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Background: The distribution and elimination of infused crystalloid fluid is known to be affected by general anesthesia, but it is unclear whether changes differ depending on whether the patient is operated in the flat recumbent position, the Trendelenburg ("legs up") position, or the reverse Trendelenburg ("head up") position. Methods: Retrospective data on hemodilution and urine output obtained during and after infusion of 1–2 L of Ringer's solution over 30–60 min were collected from 61 patients undergoing surgery under general anesthesia and 106 volunteers matched with respect to the infusion volume and infusion time. Parameters describing fluid distribution in the anesthetized and awake subjects were compared by population volume kinetic analysis. Results: General anesthesia decreased the rate constant for urine output by 79% (flat recumbent), 91% (legs up) and 91% (head up), suggesting that laparoscopic surgery per se intensified the already strong anesthesia‐induced fluid retention. General anesthesia also decreased the rate constant governing the return of the distributed fluid to the plasma by 32%, 15%, and 70%, respectively. These results agree with laboratory data showing a depressive effect of anesthetic drugs on lymphatic pumping, and further suggest that the "legs up" position facilitates lymphatic flow, whereas the "head up" position slows this flow. Both Trendelenburg positions increased swelling of the "third fluid space". Conclusions: General anesthesia caused retention of infused fluid with preferential distribution to the extravascular space. Both Trendelenburg positions had a modifying influence on the kinetic adaptations that agreed with the gravitational forces inflicted by tilting to body. [ABSTRACT FROM AUTHOR]

Abstract Background Kinetic analysis of crystalloid fluid yields a central distribution volume (V c) of the same size as the expected plasma volume (approximately 3 L) except during general anesthesia during which V c might be only half as large. The present study examined whether this difference is due to influence of the intravascular albumin balance. Methods A population volume kinetic analysis according to a three-compartment model was performed based on retrospective data from 160 infusion experiments during which 1–2.5 L of crystalloid fluid had been infused intravenously over 20–30 min. The plasma dilution based on blood hemoglobin (Hb) and plasma albumin (Alb) was measured on 2,408 occasions and the urine output on 454 occasions. One-third of the infusions were performed on anesthetized patients while two-thirds were given to awake healthy volunteers. Results The Hb-Alb dilution difference was four times greater during general anesthesia than in the awake state (+ 0.024 ± 0.060 versus − 0.008 ± 0.050; mean ± SD; P

Background: Kinetic analysis of crystalloid fluid yields a central distribution volume (Vc) of the same size as the expected plasma volume (approximately 3 L) except during general anesthesia during which Vc might be only half as large. The present study examined whether this difference is due to influence of the intravascular albumin balance. Methods: A population volume kinetic analysis according to a three-compartment model was performed based on retrospective data from 160 infusion experiments during which 1–2.5 L of crystalloid fluid had been infused intravenously over 20–30 min. The plasma dilution based on blood hemoglobin (Hb) and plasma albumin (Alb) was measured on 2,408 occasions and the urine output on 454 occasions. One-third of the infusions were performed on anesthetized patients while two-thirds were given to awake healthy volunteers. Results: The Hb-Alb dilution difference was four times greater during general anesthesia than in the awake state (+ 0.024 ± 0.060 versus − 0.008 ± 0.050; mean ± SD; P < 0.001) which shows that more albumin entered the plasma than was lost by capillary leakage. The Hb-Alb dilution difference correlated strongly and positively with the kinetic parameters governing the rate of fluid transfer through the fast-exchange interstitial fluid compartment (k12 and k21) and inversely with the size of Vc. Simulations suggest that approximately 200 mL of fluid might be translocated from the interstitial space to the plasma despite ongoing fluid administration. Conclusions: Pronounced plasma volume expansion early during general anesthesia is associated with a positive intravascular albumin balance that is due to accelerated lymphatic flow. This phenomenon probably represents adjustment of the body fluid volumes to anesthesia-induced vasodilatation. [ABSTRACT FROM AUTHOR]

Instead of employing duplex stainless steel (DSS) alone, the current effort aims to coat the 2205 DSS with hydroxyapatite (HA) coupled with carbon nanotube (CNTs) for biomedical applications to improve corrosion performance and biocompatibility. The surface of 2205 DSS has been coated with hydroxyapatite/Multiwall carbon nanotube composite particles by using the electrophoretic deposition (EPD) process to enhance corrosion resistance, biocompatibility, and osseointegration. In order to identify the ideal values for EPD factors, the current study examines the impact of the two most significant EPD variables (potential and time) on the characteristics of the deposited layer. The scanning electron microscope (SEM) is used to determine the coating properties. Potentiodynamic and cyclic polarization tests are used in Ringer's solution to evaluate the corrosion test of coated and uncoated specimens. According to the results, the ideal suspension has 65 wt.% HA and 35 wt.% multiwall carbonnanotube (MWCNT), is coated at 50 V for 2 min, and has a homogeneous morphology, a thick structure, and no cracks. Additionally, this sample had the least amount of porosity (0.572%) and the maximum rate of corrosion (0.091 mpy), making it well suited to serve as a barrier against the localized corrosion attack caused by the numerous aggressive ions that occurred in Ringer's solution during the corrosion test. [ABSTRACT FROM AUTHOR]

In order to create alloys with exceptional properties for orthopedic uses, this study focuses on the impact of zirconium (Zr) content on the structural, electrochemical, and tribological qualities of nanostructured Ti–25Nb-xZr [x = 5, 10, 15, 20, 25, and 30 atomic (at.) %] alloys. The structural evolution was investigated using XRD and SEM techniques. The mechanical characteristics of the produced alloys, including Vickers hardness and Young's modulus, were measured. In addition, the corrosion tests were performed using the OCP, EIS, and PD methods in Ringer's solution within the independent pH range at 37 °C. A ball-on-disc tribometer was used to investigate the tribological behavior of the alloys under various loads and wet conditions using the Ringer solution. It has been verified that Zr content (at. %) in the alloys had an impact on their morphologies, structural evolution, and mechanical characteristics. According to the morphological analysis, the particle and crystallite size decreases with increasing Zr content. Young's modulus and Vickers hardness show the same tendency. The EIS data demonstrated that a single passive film formed on the alloy surfaces, and the addition of Zr enhanced the corrosion resistance of the passive films. The polarization curves demonstrate that the alloys had low corrosion current densities and large passive areas without the passive films disintegrating. Likewise, the inclusion of Zr resulted in a reduction in the corrosion and passive current density values. All of these results suggested that the titanium alloys exhibit a more noble electrochemical activity caused by Zr. From the tribological perspective, it was found that the friction coefficient of the alloys reduced with increasing Zr content.

The present research investigated the effect of nanobubbles in Ringer's solution on calcified plaque within ex vivo coronary and peripheral artery tissue. The goal of the work was to determine whether nanobubbles generated using an alternating magnetic field (AMF) system can reproducibly reduce the size of plaque obstructions in ex vivo pericardial tissue specimens compared to that in an untreated control. Nanoparticle tracking analysis (NTA) measurements were used to first confirm that AMF can produce nanobubbles in Ringer's solution as well as it does in water. Experiments were performed in which ex vivo human coronary artery and peripheral artery tissues containing plaque were exposed to Ringer's solution with and without the presence of AMF generated nanobubbles. Measurements on intravascular optical coherence tomography (IVOCT) images consistently indicated that plaque volume is significantly reduced in the presence of nanobubbles. A theory of induced dissolution by nanobubble/nanoparticle cluster formation provides a causal explanation for the observed reductions in plaque size.

The porous hydroxyapatite coatings with a spherical structure were formed on commercially pure titanium (CP-Ti) by the micro-arc oxidation (MAO) in an alkaline electrolyte (hydroxyapatite + 1 M potassium hydroxide) at the applied voltage of 140, 160, 180 V and deposition time of 1 and 2 min. It was determined that by increasing voltage from 140 to 160 V the Ca/P ratio increases from 1.54 to 1.69, i.e., the composition of hydroxyapatite (HA) approaches to the biological one that accelerates formation of the interfacial bond between the implant and bone tissue. It was shown that increasing deposition time from 1 to 2 min at the voltage of 140 V promotes increasing Ca/P ratio. The corrosion resistance of CP-Ti with HA coatings was studied in Ringer's solution at a temperature of 37 °C. The best corrosion protection was observed for the coating deposited at 160 V, 1 min, when the thickness of the coating and HA formation is the highest. [ABSTRACT FROM AUTHOR]

The effect of hygrothermal aging on the tribological and mechanical behaviors of UHMWPE biocomposites reinforced with different weight fractions of mollusc shell (MS) particles was investigated. The developed MS-UHMWPE biocomposites samples were subjected to accelerated hygrothermal aging in Ringer's solution at 80°C. The results showed that hygrothermal aging increases the tribological behavior of these biocomposites. The effect of hygrothermal aging on the wear resistance depends on the reinforcement rate of the MS particles. The mechanical properties of the MS-UHMWPE biocomposite were affected by hygrothermal aging as well as by the weight content of the added MS particles. The modulus of elasticity increased with increasing MS particle content for all tested materials. A scenario of the wear mechanism of aged biocomposites will be proposed. [ABSTRACT FROM AUTHOR]

The formation of hydroxyapatite coating on BT6 titanium alloy under the combined treatment: nitriding and plasma-electrolytic oxidation in an alkaline electrolyte (hydroxyapatite + 1M potassium hydroxide) was investigated. Such treatment promotes the growth of the Ca10 (PO4)6(OH)2 hydroxyapatite phase, that can be attributed to an increase of the centers of hydroxyapatite crystallization on the pre-nitrided surface. The hydroxyapatite coating on pre-nitrided surface provided higher hydrophilicity and better corrosion resistance in Ringer's solution at a temperature of 37°C. [ABSTRACT FROM AUTHOR]

Aim To evaluate the association of intravenous fluid (IVF) therapy on the length of time from arrival at the emergency department (ED) until awakening in cases of acute alcohol intoxication. Methods This single‐center, prospective, observational study was conducted in the ED of the Self‐Defense Forces Central Hospital during October 1, 2018 to July 31, 2019. Patients with 1,000 mL bolus of lactated Ringer's solution and those without bolus were compared. The primary outcome was the length of time until awakening. Secondary outcomes were the length of stay in the ED and occurrence of conditions requiring extra care. Predictors of the occurrence of any event requiring extra care were identified. Results We included 201 patients, of whom 109 received IVF and 92 did not. No significant difference existed in the baseline characteristics between the groups. The median length of time until awakening did not significantly differ between the groups (P = 0.77). Multivariable regression analysis adjusted by age, sex, hemoglobin, blood alcohol concentration, and initial Glasgow Coma Scale (GCS) score demonstrated that the regression coefficient of IVF for length of time until awakening was −9.55 (95% confidence interval [CI], −36.2 to 17.2). Hemoglobin (regression coefficient, 10.1; 95% CI, 0.38–19.9) and initial GCS score (regression coefficient, −7.51; 95% CI, −10.8 to −4.21) were significantly associated with length of time. Conclusion IVF therapy was not associated with the length of time until awakening in patients with acute alcohol intoxication in the ED. Routine IVF administration was unnecessary.

Objective: Acute and hard-to-heal wounds are a significant burden to both a patient's quality of life and resources in healthcare systems. Here, we evaluate the outcomes of a non-comparative case series study in which Ringer's solution-preactivated polyacrylate dressings were used to treat acute and hard-to-heal wounds (the presence of Ringer's solution provides a wound dressing that allows, upon application, the immediate hydration of the underlying wound tissue). Method: Patients with acute and hard-to-heal wounds were enrolled into an open-labelled, non-comparative observational study. Patients were treated with Ringer's solution-preactivated polyacrylate dressings to enable wound debridement and wound cleansing for up to 12 weeks. Results: A total of 303 patients were enrolled in the study and 278 were included in the analysis. Wound size decreased, from a median of 3.6cm2 (interquartile range (IQR): 1.2–9.3] at baseline to a median of 2.6cm2 (IQR: 1.1–7.8] at 84 days. Relative wound area reduction (WAR) was 43.1% at 84 days and estimated probability of achievement of a WAR of ≥40% and ≥60% was 68.7% and 53.4%, respectively. Median time to achieve a WAR of ≥40% and ≥60% was 54 days and 75 days, respectively. The median percentage of wound area covered by fibrin had decreased from 50.0% to 10% and granulation tissue had increased from 25% to 50% after 84 days. In addition, periwound skin condition, local signs of infection and pain all showed improvement. The majority of the wounds were assessed as 'healed' or 'better' at the conclusion of the evaluation period. Conclusion: Based on the findings of this study, the use of Ringer's solution-preactivated polyacrylate dressings in daily practice has the potential to improve clinical outcomes, including healing, in patients with acute and hard-to-heal wounds. [ABSTRACT FROM AUTHOR]

Dynamic friction coefficient (COF) of the reciprocating sliding contact of the conventional UHMWPE, was investigated in four different environments (dry contact; distilled water; pure Ringer's solution and with PMMA particles), at five values of low normal load (0.1–1 N) and three values of sliding speed (4 - 12 mm/s). Significant differences of COF values occurred at the lowest load (0.1 N), whereas sliding speed did not influence COF values. Addition of PMMA particles in Ringer's solution produced significant increase of COF values, especially at the lowest load of 0.1 N. For the dry contact and the highest load (1 N), steady state was reached shortly after the beginning of the test and friction coefficient had uniform behaviour. In the case of wet environment and the lowest load, steady state was not reached and the friction coefficient exhibited non-reproducible random behaviour. According to the Hertz theory, 0.5 N load corresponded to the elastic stress of 48.7 MPa, thus surpassing the values of the elastic limits, hardness and true yield stress of the UHMWPE, and the behaviour of the friction coefficient was drastically different below and above this load value. It can be assumed that below the 0.5 N load, viscoelastic response, accompanied with plastic deformation is dominant, with transition to mainly plastic deformation for the higher loads. [ABSTRACT FROM AUTHOR]

This study aims to investigate the anticorrosive properties of Zr2.5Nb alloy intended for possible applications in the human body; it was tested for 2 days in Ringer solution (an artificial analogue for human blood, considered the most corrosive body fluid). For Zr2.5Nb samples, in situ electrochemical measurements to assess the anticorrosive properties were applied, such as open circuit potential (OCP), polarization resistance (Rp), potentiodynamic polarization (PD) and cyclic voltammetry (CV). The electrochemical results show that the Zr2.5Nb alloy shows a positive and stable trend according to the open circuit potential, but with a modest corrosion rate in the form of pitting, deduced from the analysis of the polarization resistance and cyclic voltammetry data. [ABSTRACT FROM AUTHOR]

The long-term performance of steels is affected by the simultaneous actions of wear and corrosion, known as tribocorrosion. The tribocorrosion behavior of fully austenitic steels: Fe-Mn-xAl-C (x = 0, 3.5 and 8.3 wt.%) in Ringer's solution was investigated by using a pin on disk tribometer adapted with a three-electrode corrosion cell. Open circuit potential and coefficient of friction evolution as well as polarization curves were measured. Corrosion rates were calculated by the Tafel extrapolation method, and wear rates were calculated by using a linear profilometer. Pure and total wear rates were higher for the 3Al alloy due to the greater precipitation and embedded calcium minerals, hydroxides, and oxides on the surface, to the detachment of the deformed layer and its adhesion to the counterbody. Additionally, the 8Al alloy exhibited the lowest tendency to corrosion and corrosion rate and the greatest synergistic effect, indicating that this alloy is more sensitive to this effect than the other alloys. For the three materials, the change in the wear rate due to corrosion had a greater contribution to the synergy than the change in corrosion rate due to wear and the damage in the materials was derived mainly from pure mechanical wear. [ABSTRACT FROM AUTHOR]

A search for a sorbent capable of simultaneously extracting both phosphate anions and ammonium cations from a highly competitive medium like the biological environment of the human's body was realized. For this purpose a comparative study of a sorption of ammonium and phosphate ions from aquatic environments in the absence of any backgrounds electrolytes and from Ringer's solution by activated charcoal, its oxidized forms and mineral amorphous sorbents - powdered titanium silicate, as well as spherically granular hydrous zirconium silicate and titanium dioxide, obtained by original methods of synthesis, as well as some of their ion-substituted forms in comparison with commercially available silica gel was carried out. The features of the sorption of ammonium cations and phosphate anions by the studied sorbents are discussed. It was established that sorption properties of the sorbents depend strongly from their chemical nature. It determines a selectivity of ion-exchange and a possibility of chemosorption processes in Ringer's solution. A relationship between the sorption of calcium cations and phosphate anions from Ringer's solution was supposed which made it possible to assume the chemosorption mechanism. Based on the sorption mechanism understanding the sorption properties of titanium silicate with respect to phosphate anions were considerable improved by converting the initial sample into Ca- and Ce-ion-substituted forms without significant loss of its high sorption properties toward ammonium cations. [ABSTRACT FROM AUTHOR]

Introduction: Investigations of responses of animals and humans to changes of plasma volume are usually reported as average responses of groups of individuals. This ignores considerable quantitative variation between individuals. We examined the hypothesis that individual responses follow a common temporal pattern with variations reflecting different parameters describing that pattern., Methods: We illustrate this approach using data of Hahn, Lindahl and Drobin (Acta Anaesthesiol Scand.2011, 55:987-94) who measured urine volume and haemoglobin dilution of 10 female subjects during intravenous Ringer infusions for 30 min and subsequent 3.5 h. The published time courses were digitised and analysed to determine if a family of mathematical functions accounted for the variation in individual responses., Results: Urine excretion was characterised by a time delay (Td) before urine flow increased and a time course of cumulative urine excretion described by a logarithmic function. This logarithmic relation forms the theoretical basis of a family of linear relations describing urine excretion as a function of Td. Measurement of Td enables estimation of subsequent values of urine excretion and thereby the fraction of infused fluid retained in the body., Conclusion: The approach might be useful for physiologists and clinical investigators to compare the response to infusion protocols when both test and control responses can be described by linear relations between cumulative urine volume at specific times and Td. The approach may also be useful for clinicians by complementing strategies to guide fluid therapy by enabling the later responses of an individual to be predicted from their earlier response., (© 2024 The Author(s). Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.)

Large osteochondral defects are a major challenge in orthopedics, for which osteochondral allograft (OCA) transplantation is nowadays considered as an option, especially in young patients. However, a major issue with OCA is the need for graft storage, which ensures adequate cartilage integrity over time. The aim of this study was to test how long a Ringer-based storage solution can provide good graft quality after explantation and thus meet the requirements for OCA. For this purpose, human osteochondral allografts of the knee and ankle were analyzed. Live/Dead analysis was performed and glycosaminoglycan, as well as hydroxyproline content, were measured as crucial chondrocyte integrity factors. Furthermore, biomechanical tests focusing on stress relaxation and elastic compression modulus were performed. The critical value of 70% living chondrocytes, which corresponds to a number of 300 cells/mm², was reached after an average of 16 weeks of storage. In addition, a constant cell shrinkage was observed over time. The amount of glycosaminoglycan and hydroxyroline showed a slight and constant decrease over time, but no significant differences when compared from Day 0 to the values at Weeks 40-43. Biomechanical testing also revealed no significant differences at the different time points. Therefore, the results show that the Ringer-based storage solution at 4°C is able to provide a chondrocyte survival of 70% until Week 16. This is comparable to previously published storage solutions. Therefore, the study contributes to the establishment of a Ringer-based osteochondral allograft transplantation system for countries where medium-based storage solution cannot be approved., (© 2024 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

Electrochemical characteristics and semiconducting behavior of additively manufactured electron beam melted (EBM) and wrought (WR) Ti–6Al–4V (Ti-G5) are compared in Ringer's physiological solution. X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) confirmed the α + β structure of the tested materials, with two different microstructure types of "bimodal" and "basket-weave" for WR and EBM, respectively. Potentiodynamic polarization (PDP) revealed that the corrosion current density for EBM (icorr = 0.27 ± 0.06 μA cm−2) is less than the WR (icorr = 0.70 ± 0.05 μA cm−2). Moreover, potentiostatic polarization (PS) that was employed to form the passive layers at three different potentials of 300, 500, and 700 mVAg/AgCl, showed that the passive films on the EBM sample are thinner. This finding was confirmed by electrochemical impedance spectroscopy (EIS). Furthermore, through Mott–Schottky (M–S) analysis, donor densities on WR passive films were found to be ~ 1.5 times larger than EBM. Although PS and EIS confirmed that the passive layer on EBM is thinner, it provides higher corrosion resistance than WR. The passive layer on both samples were found to have n-type characteristics with a duplex structure. [ABSTRACT FROM AUTHOR]

In the present study, the effect of thermal oxidation (TO) treatment duration on the fretting wear behavior of Ti6Al4V alloy in Ringer's solution was investigated. The treatment was carried out on Ti6Al4V coupons at 650 °C for different treatment durations of 16 h, 24 h, and 48 h in air. Fretting wear tests were carried out in Ringer's solution on TO-treated and untreated coupons using a ball-on-flat contact configuration with the following test parameters: displacement amplitude of 50 ± 5 μm, a normal load of 0.98 N, frequency of 5 Hz, counter body of alumina ball of 10 mm diameter. TiO2 layer formed due to TO treatment has been found to influence friction coefficient and the fretting wear resistance. TO treatment for 48 h resulted in about 80% reduction in wear rate compared to that of the untreated coupons. [ABSTRACT FROM AUTHOR]

Continuous glucose monitoring (CGM) represents an integral of modern diabetes management, however, there is still a lack of sensor performance data when rapidly consuming different liquids and thus changing total body water. 18 healthy adults (ten females, age: 23.1 ± 1.8 years, BMI 22.2 ± 2.1 kg·m−2) performed four trial visits consisting of oral ingestion (12 mL per kg body mass) of either a 0.9% sodium chloride, 5% glucose or Ringer's solution and a control visit, in which no liquid was administered (control). Sensor glucose levels (Dexcom G6, Dexcom Inc., San Diego, CA, USA) were obtained at rest and in 10-min intervals for a period of 120 min after solution consumption and compared against reference capillary blood glucose measurements. The overall MedARD [IQR] was 7.1% [3.3–10.8]; during control 5.9% [2.7–10.8], sodium chloride 5.0% [2.7–10.2], 5% glucose 11.0% [5.3–21.6] and Ringer's 7.5% [3.1–13.2] (p < 0.0001). The overall bias [95% LoA] was 4.3 mg·dL−1 [−19 to 28]; during control 3.9 mg·dL−1 [−11 to 18], sodium chloride 4.8 mg·dL−1 [−9 to 19], 5% glucose 3.6 mg·dL−1 [−33 to 41] and Ringer's solution 4.9 mg·dL−1 [−13 to 23]. The Dexcom G6 CGM system detects glucose with very good accuracy during liquid solution challenges in normoglycemic individuals, however, our data suggest that in people without diabetes, sensor performance is influenced by different solutions. [ABSTRACT FROM AUTHOR]

The chaya (Cnidoscolus aconitifolius) is a green, leafy vegetable domesticated since ancient Mayan culture, offering an abundance of valuable metabolites. This study investigated how three different extracts from Chaya leaves inhibit the corrosion of pure magnesium in Ringer's solution. Various techniques, such as scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were employed to analyze the chemical, morphological, and structural aspects of the products formed on the magnesium surface after a 14-day exposure. The in vitro corrosion behavior was studied through open-circuit potential measurements and electrochemical impedance spectroscopy during immersion tests in physiological Ringer's solution with each extract. Polarization curves were also obtained to determine j corr and E corr. Different morphologies were observed on the surfaces of the substrates due to each extract's polarity. However, the results showed that the three chaya extracts retard, to some extent, the corrosion process, reducing the pH (from 9 to 6) and j corr (from 18.2 to 1.12 µAcm−2) in comparison to untreated samples. The ethyl acetate-derived extract exhibited the highest percentage of inhibition (92.9%) according to the impedance results. These extracts could be a promising alternative for developing potential temporary implants for the human body and diverse industrial applications. [Display omitted] • Green corrosion inhibitors were extracted from Chaya leaves. • Chaya leaf extracts inhibit the corrosion of pure Mg in Ringer's solution. • The Chaya extract in ethyl acetate exhibited 92.9% of inhibition. • XPS confirmed the adsorption of organic components on the surfaces. • All three extracts efficiently regulate the local pH. [ABSTRACT FROM AUTHOR]

BackgroundOptical coherence tomography (OCT) is an important modality used in coronary intervention. However, OCT requires a high amount of contrast media, limiting its extensive application in clinical practice. This study compared OCT images of coronary lesions obtained using contrast media and very-low contrast combined Ringer's solution (VLCCR) in patients with acute coronary syndrome (ACS).MethodsThirty ACS patients with a total of 36 native lesions and stenoses from 70 to 90% were included in this study. Two kinds of flushing media (a contrast medium and VLCCR) were used in succession in a random order for OCT image pullback of each lesion. VLCCR method is using low volume contrast (4–5 ml) injected into the guiding catheter previously combination with injector infused Ringer's solution instead of pure contrast medium. The safety of procedure was evaluated by recording the patients ‘symptoms, changes of ECG, blood pressure and heart rate. OCT images were analyzed to determine the image clarity. Lumen area and diameter were also measured and the consistency between the two media was compared.ResultsOCT procedure using either contrast or VLCCR did not show any peri-procedural adverse events. There was no difference in changes of blood pressure and heart rate in both procedures, however, VLCCR procedure showed less procedure-related symptoms and ECG changes. We found that the percentage of clear image frame was equivalent between the contrast and VLCCR media (98.0 vs. 96.9%, P = 0.90). We also observed a high degree of similarity between the different lesion phenotypes of ACS for both media. There was a linear correlation of the phenotypes obtained with these two different methods, and a significant correlation was observed between measurements obtained with contrast and VLCCR without correction for the refractive index of VLCCR (correlation coefficients ranged between 0.829 and 0.948).ConclusionsOCT imaging using VLCCR for blood clearance is feasible and safe and provides similar imaging quality compared to OCT imaging obtained using radiographic contrast media for ACS patients.

This study aims to evaluate the microstructure and corrosion resistance of selective laser-melted 17-4 precipitation hardening (PH) martensitic stainless steel and the corresponding wrought specimen in Ringer's solution. The results showed that the selective laser melting (SLM) process improved the corrosion behavior of the alloy in the solution. Microscopic studies revealed that the wrought sample has fine lath martensite with elongated δ-ferrite stringers, while selective laser-melted (SLMed) alloy did not show any obvious phase. However, at higher magnifications, the SLMed specimen exhibited a fine cellular/columnar microstructure owing to the high cooling rate in the SLM technique and uniform distribution of elements. In addition, corrosion studies emphasized that the SLMed alloy possessed a higher charge transfer resistance than the wrought sample. Charge transfer resistances of the SLMed and the wrought sample were about 14.1 and 1.5 KΩ cm2, respectively. Moreover, corrosion current density of the SLMed alloy after 100 h of immersion was about ten times lower than the wrought one. The improved electrochemical behavior of SLMed 17-4 PH stainless steel can be attributed to the reduction of nonuniform distribution of alloying elements such as Nb during the solidification process as a consequence of high cooling rate of the SLMed alloy. Moreover, the development of galvanic cells and a low anode/cathode area ratio are other factors related to the decreased corrosion performance of the wrought alloy. [ABSTRACT FROM AUTHOR]

Background: Crystalloid fluid infused during the induction of spinal anesthesia is involved in a complex set of physiological responses, including vasodilatation, reactive vasoconstriction, and changes in mean arterial pressure (MAP). The present evaluation compares the modeled capillary leakage in anesthetized versus nonanesthetized body regions. Methods: Ten female volunteers (mean age, 29 years) received 25 ml/kg of Ringer's acetate over 60 min during experimental spinal anesthesia. Blood hemoglobin was measured repeatedly in the radial artery (reference), arm (cubital) vein, and leg (femoral) vein for 240 min. Each pattern of data served as a dependent variable in volume kinetic analyses that used mixed models software and MAP as covariate. Results: The capillary leakage of fluid from the plasma to the extravascular space peaked at 17 ml/min when MAP was 100 mmHg, and the two venous curves were virtually identical. At MAP 60 mmHg, the rate was reduced to 10‐12 ml/min when assessed in arterial blood and leg vein blood, but only 5 mmHg in blood collected from the arm vein. The distribution half‐life of infused fluid was then 40 min in the leg and 80 min in the arm. These results suggest that vasoconstriction in nonanesthetized body regions halves the capillary leakage that is observed in vasodilated, anesthetized body regions. Conclusion: Graded hypotension during spinal anesthesia reduced the capillary filtration of fluid as determined by volume kinetic analysis. The effect was twice as great when venous blood was sampled from a nonanesthetized body region than from an anesthetized body region. [ABSTRACT FROM AUTHOR]

Abstract Background The water volume of the endothelial glycocalyx layer has been estimated at 0.7 to 1.7 L using tracer methods of unclear value. The present study attempts to measure this fluid volume by analyzing the kinetics of a crystalloid fluid load. Methods An intravenous infusion of approximately 1 L of Ringer’s acetate was administered to 35 healthy volunteers, and the central volume of distribution of the water volume was calculated from the urinary excretion and frequent measurements of the fluid-induced hemodilution using mixed-effects modeling software. Comparisons were made with the plasma volume derived from three published anthropometric regression equations based on isotope measurements. In a second analysis, up to 2.5 L of Ringer’s was administered to 60 volunteers selected from a cohort of 160 to have as similar hematocrits as possible to the volunteers whose data were used to create the anthropometric equations. Results Volume kinetics showed that the infused crystalloid fluid occupied a larger central fluid space than was estimated with the isotope measurements. The first analysis of the 35 subjects indicated a mean difference of 0.51 L in males and 0.49 L in females. The second, larger analysis showed a mean excess volume of 0.43 L, which was approximately 15% of the circulating plasma volume. Conclusions A crystalloid fluid load expands a 0.4–0.5 L larger central fluid space than the circulating plasma volume. The excess volume is probably located in the glycocalyx layer.

The study was aimed to investigate the positive impact of bicarbonate Ringer's solution on postoperative outcomes in patients who underwent laparoscopic right hemihepatectomy. Patients in the two groups were infused with lactated Ringer's solution (LRS, n = 38) and the bicarbonate Ringer's solution (BRS, n = 38) at a rate of 5 ml·kg -1 ·h -1 . The stroke volume was monitored and 200 ml of hydroxyethyl starch with 130/0.4 sodium chloride injection (Hes) of a bolus was given in the first 5-10 min. The main outcome was to test lactic acid (LAC) concentration before and after surgery. The concentrations of LAC in the LRS group were higher than in the BRS group at 2 h after operation began, at the end of the operation and 2 h after the operation. Overall, the parameters including pH, base excess (BE), HCO 3 - , aspartate transaminase (AST) and alanine transaminase (ALT) were improved. The values of bilirubin in the LRS group were higher and albumin were lower than in the BRS group at post-operation 1st and 2nd day (P<0.05). The time of prothrombin time (PT) and activated partial thromboplastin time (APTT) in the LRS group were longer than that in the BRS group at post-operation 1st and 2nd day (P<0.05). Likewise, the concentrations of Mg 2+ , Na + and K + also varied significantly. The length of hospital was reduced, and the incidence of premature ventricular contractions (P = 0.042) and total complications (P = 0.016) were lower in group BRS. TRIAL REGISTRATION: The study was registered at clinicalTrials.gov with the number ChiCTR2000038077 on 09/09/2020., (© 2024. The Author(s).)

Abstract: Background: Normal saline solution (NSS) and Ringer's acetate solution (RAS) are commonly given to critically ill patients as a fundamental fluid therapy. However, the effect of RAS and NSS on sepsis patient outcomes remains unknown. Methods: We conducted a single-center prospective open-label parallel controlled trial to enroll adult patients (>18 years old) diagnosed with sepsis. Participants received either RAS or NSS for intravenous infusion for 5 days. The primary outcome was the incidence of major adverse kidney events within 28 days (MAKE28). Secondary outcomes included 30-/90-day mortality, acute kidney injury, and hyperchloremia. The patients were then reclassified as NSS-only, RAS-only, and RAS + NSS groups according to the type of fluid they had received before enrollment. Thereafter, a secondary post hoc analysis was performed. Results: Two hundred fifty-five septic patients were screened, and 143 patients (51.0% in RAS group and 49.0% in NSS group) were enrolled in the study. Each group received a median of 2 L of fluid administration during five interventional days. Of the patients, 39.3% had received 500 mL (500-1,000 mL) of balanced salt solutions (BSSs) before intensive care unit (ICU) admission. There was no statistical difference among the RAS and NSS group on the primary outcome MAKE28 in the initial analysis (23.3% vs. 20.0%; OR, 1.2 [0.6 to 2.2]; P = 0.69). MAKE28 was observed in 23.3% of RAS-only versus 27.3% of NSS-only group patients (0.82 [0.35-1.94], P = 0.65) in the secondary post hoc analysis. The patients in the NSS-only group had a longer invasive mechanical ventilation days and a trend toward the accumulation of serum chloride. Conclusion: This study observed no statistically significant difference on MAKE28 and secondary outcomes among sepsis patients receiving RAS and NSS. However, it is unclear whether the large amount of fluid resuscitation before ICU admission and carrier NSS narrowed the difference between BSSs and NSSs., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Shock Society.)

Resuscitation solution is one of the main interventions provided for septic shock patients, although there is no general consensus regarding the optimal type of solution. Therefore, a trometamol-balanced solution (TBS) was designed as a resuscitation solution. The aim of this study is to assess the effects of TBS versus Ringer's solution (RS) in a rat septic model. Septic shock was induced in 16 male Wistar-Kyoto rats through lipopolysaccharide (LPS) induction; these rats were assigned at a ratio of 1:1 to RS and TBS groups. Blood examinations were performed using an Abbott i-STAT analyzer with CG4+ (for pH, pressure of carbon dioxide, pressure of oxygen, total carbon dioxide, bicarbonate, base excess, oxygen saturation, and lactate) and CG6+ (for sodium, potassium, chloride, blood glucose, blood urea nitrogen, hematocrit, and hemoglobin) and enzyme-linked immunosorbent assay kits (calcium, magnesium, creatinine, aspartate aminotransferase, alanine aminotransferase, bilirubin, and albumin) during the septic state. The biochemical parameters, electrolytes, and blood gas parameters implied similar trends and the majority of data showed no considerable changes between groups after LPS-induced septic shock. However, the pH values of the TBS group were more stable compared with those of the RS group. This indicated that TBS might be more effective in metabolic acidosis alleviation. In summary, TBS is safe and feasible in this study and may offer advantages in septic shock cases without hepatic diseases. Future research will focus on applying TBS in other different animal disease models and the clinical usage of TBS. [ABSTRACT FROM AUTHOR]

High entropy alloys (HEAs) have received tremendous attention in different applications because of their excellent corrosion resistance and superior mechanical properties. In the present work, a novel TiNbMoMnFe high entropy alloy system was synthesized and deposited on AISI 316L by DC magnetron sputtering system. The microstructure of the resulting thin film was evaluated by grazing incidence X-ray diffraction and field emission electron microscope. It was found that the thin film microstructure is composed of a crystalline solid solution (grain size of 76 nm) and an amorphous phase. The electrochemical investigations in Ringer's solution revealed that a thin film of 670 nm thick high entropy alloy has a low corrosion current density of 0.024 μA cm−2, approximately 30% lower than that of the uncoated 316L. Meanwhile, the HEA thin film showed the highest pitting corrosion resistance and stability of the passive film. The wettability examinations exhibited that the coated sample has a high contact angle of 90° in contrast to 60° for the uncoated ones. In summary, the TiNbMoMnFe high entropy alloy thin film shows great potential for use in biomaterial applications. [ABSTRACT FROM AUTHOR]

This study aims to investigate the anticorrosive properties of Zr2.5Nb alloy intended for possible applications in the human body; it was tested for 2 days in Ringer solution (an artificial analogue for human blood, considered the most corrosive body fluid). For Zr2.5Nb samples, in situ electrochemical measurements to assess the anticorrosive properties were applied, such as open circuit potential (OCP), polarization resistance (Rp), potentiodynamic polarization (PD) and cyclic voltammetry (CV). The electrochemical results show that the Zr2.5Nb alloy shows a positive and stable trend according to the open circuit potential, but with a modest corrosion rate in the form of pitting, deduced from the analysis of the polarization resistance and cyclic voltammetry data.

The long-term performance of steels is affected by the simultaneous actions of wear and corrosion, known as tribocorrosion. The tribocorrosion behavior of fully austenitic steels: Fe-Mn-xAl-C (x = 0, 3.5 and 8.3 wt.%) in Ringer’s solution was investigated by using a pin on disk tribometer adapted with a three-electrode corrosion cell. Open circuit potential and coefficient of friction evolution as well as polarization curves were measured. Corrosion rates were calculated by the Tafel extrapolation method, and wear rates were calculated by using a linear profilometer. Pure and total wear rates were higher for the 3Al alloy due to the greater precipitation and embedded calcium minerals, hydroxides, and oxides on the surface, to the detachment of the deformed layer and its adhesion to the counterbody. Additionally, the 8Al alloy exhibited the lowest tendency to corrosion and corrosion rate and the greatest synergistic effect, indicating that this alloy is more sensitive to this effect than the other alloys. For the three materials, the change in the wear rate due to corrosion had a greater contribution to the synergy than the change in corrosion rate due to wear and the damage in the materials was derived mainly from pure mechanical wear.

• Hypovolemia with edema is common in preeclampsia, but the reason is unclear. • The distribution of infused fluid was studied by volume kinetic analysis. • The rate of distribution of Ringeŕs solution was normal. • The return flow from the interstitial space to the plasma was markedly decreased. • Decreased return flow promotes hypovolemia, edema, and hypoalbuminemia. Hypovolemia and peripheral edema are frequent components of preeclampsia. The level of the dysregulation of the body fluid distribution is unclear, which complicates the choice of infusion fluid during surgery. The present fluid kinetic study challenges whether the maldistribution of fluid is due to increased capillary leakage or to poor return of already distributed fluid, which occurs via lymphatic pathways. Ringeŕs solution was infused in 10 awake non-pregnant women, eight healthy pregnant women, and in eight women with mild-to-moderately severe preeclampsia. Distribution and redistribution of the infused fluid was calculated with mixed models kinetics based on the excreted urine volumes and 675 measurements of hemodilution. Differences in fluid kinetics between the three groups were studied with covariance analysis. The return flow of fluid volume to the plasma after distribution (rate parameter k 21) was almost zero in women with preeclampsia, while the rate was normal in the other two groups (P < 0.001). By contrast, the capillary leakage rate of fluid in response to the infusion (k 12) was normal. The urinary excretion (k 10) was moderately accelerated. Decreased flow of extravascular fluid to the plasma was the key disturbance in women with preeclampsia. Such decreased flow alone promotes hypovolemia, peripheral edema, and hypoalbuminemia, and may be explained by inhibition of lymphatic pumping and/or a decreased interstitial hydrostatic pressure due to the presence of vasoactive and inflammatory signal molecules. The moderately accelerated urine flow may be due to "pressure diuresis" in response to hypertension. [ABSTRACT FROM AUTHOR]

Kinetic analysis of fluid volume shifts can identify two interstitial fluid compartments with different turnover rates, but how they are connected to the bloodstream is unknown. Retrospective data were retrieved from 217 experiments where 1.5 L of Ringer's solution (mean) had been administered by intravenous infusion over 30 min to awake and anesthetized humans (mean age 40 years). Urinary excretion and hemoglobin-derived plasma dilution served as input variables in a volume kinetic analysis using mixed models software. Possible modes of connection between the two interstitial fluid compartments and the bloodstream were judged by covariance analysis between kinetic rate constants, physiological variables, and time factors. The return flow of already distributed fluid to the plasma via a fast-exchange interstitial compartment was inhibited ongoing infusion of fluid (−38 %), which was probably due to increase of the venous pressure during volume loading. Ongoing infusion also greatly retarded the entrance of fluid to the slow-exchange compartment (−85 %), which suggests that infused Ringer's first had to enter the fast-exchange compartment. A high mean arterial pressure markedly increased the urine output and, to a lesser degree, also the rate of entrance of fluid to the fast-exchange compartment. Moreover, a high blood hemoglobin concentration retarded the rate of entrance of fluid to the fast-exchange compartment. The fast-exchange but not the slow-exchange interstitial fluid compartment was affected by intravascular events, which suggests that only the fast-exchange compartment is directly connected to the circulating blood. • The interstitial space contains two functional interstitial fluid compartments. • They are either placed in parallel or in series with the plasma volume. • Covariance analyses were performed in 217 infusion experiments. • Only the fast-exchange compartment was affected by intravascular events. • The results suggest a serial connection between the three fluid compartments. [ABSTRACT FROM AUTHOR]

Continuous glucose monitoring (CGM) represents an integral of modern diabetes management, however, there is still a lack of sensor performance data when rapidly consuming different liquids and thus changing total body water. 18 healthy adults (ten females, age: 23.1 ± 1.8 years, BMI 22.2 ± 2.1 kg·m−2) performed four trial visits consisting of oral ingestion (12 mL per kg body mass) of either a 0.9% sodium chloride, 5% glucose or Ringer’s solution and a control visit, in which no liquid was administered (control). Sensor glucose levels (Dexcom G6, Dexcom Inc., San Diego, CA, USA) were obtained at rest and in 10-min intervals for a period of 120 min after solution consumption and compared against reference capillary blood glucose measurements. The overall MedARD [IQR] was 7.1% [3.3–10.8]; during control 5.9% [2.7–10.8], sodium chloride 5.0% [2.7–10.2], 5% glucose 11.0% [5.3–21.6] and Ringer’s 7.5% [3.1–13.2] (p < 0.0001). The overall bias [95% LoA] was 4.3 mg·dL−1 [−19 to 28]; during control 3.9 mg·dL−1 [−11 to 18], sodium chloride 4.8 mg·dL−1 [−9 to 19], 5% glucose 3.6 mg·dL−1 [−33 to 41] and Ringer’s solution 4.9 mg·dL−1 [−13 to 23]. The Dexcom G6 CGM system detects glucose with very good accuracy during liquid solution challenges in normoglycemic individuals, however, our data suggest that in people without diabetes, sensor performance is influenced by different solutions.

A corrosion study of high purity magnesium in two simulated physiological solutions (Ringer's solution and Hank's solution) is reported. The electrochemical behavior of pure magnesium rotating disc electrode (RDE) was examined using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques. The rotation affects the potentiodynamic polarisation curves and makes a shift in the anodic branches because of the dissolution of the corrosion layer. The EIS results showed the presence of three-time constant attributed to formation of the protective film on the Mg surface, the faradic process and the adsorption phenomena. The formation of a compact layer on magnesium surface, offers a higher corrosion protective ability for Mg. The thickness of this layer increase subsequently with increase in immersion time. The magnesium surface morphology was characterized by scanning electron microscopy (SEM). The composition and the microstructure of the corrosion product film were carried out using X-ray photoelectric spectroscopy (XPS) and X-ray diffraction (XRD). Brucite, calcite and magnesium calcite were detected in both medium, while aggregated particles containing a high concentration of phosphorus were formed on Mg in Hunk's solution. [ABSTRACT FROM AUTHOR]

Background: Volume replacement with crystalloid fluid is the conventional treatment of hemorrhage. We challenged whether a standardized amount of 5% or 20% albumin could be a viable option to maintain the blood volume during surgery associated with major hemorrhage. Therefore, the aim of this study was to quantify and compare the plasma volume expansion properties of 5% albumin, 20% albumin, and Ringer-lactate, when infused during major surgery., Methods: In this single-center randomized controlled trial, fluid replacement therapy to combat hypovolemia during the hemorrhagic phase of cystectomy was randomly allocated in 42 patients to receive either 5% albumin (12 mL/kg) or 20% albumin (3 mL/kg) over 30 min at the beginning of the hemorrhagic phase, both completed by a Ringer-lactate replacing blood loss in a 1:1 ratio, or Ringer-lactate alone to replace blood loss in a 3:1 ratio. Measurements of blood hemoglobin over 5 h were used to estimate the effectiveness of each fluid to expand the blood volume using the following regression equation: blood loss plus blood volume expansion = factor + volume of infused albumin + volume of infused Ringer-lactate., Results: The median hemorrhage was 848 mL [IQR: 615-1145]. The regression equation showed that the Ringer-lactate solution expanded the plasma volume by 0.18 times the infused volume while the corresponding power of 5% and 20% albumin was 0.74 and 2.09, respectively. The Ringer-lactate only fluid program resulted in slight hypovolemia (mean, - 313 mL). The 5% and 20% albumin programs were more effective in filling the vascular system; this was evidenced by blood volume changes of only + 63 mL and - 44 mL, respectively, by long-lasting plasma volume expansion with median half time of 5.5 h and 4.8 h, respectively, and by an increase in the central venous pressure., Conclusion: The power to expand the plasma volume was 4 and almost 12 times greater for 5% albumin and 20% albumin than for Ringer-lactate, and the effect was sustained over 5 h. The clinical efficacy of albumin during major hemorrhage was quite similar to previous studies with no hemorrhage., Trial Registration: ClinicalTrials.gov NCT05391607, date of registration May 26, 2022., (© 2024. The Author(s).)

Background: The choice of fluid resuscitation in Traumatic Hemorrhagic shock (THS) remains a critical aspect of patient management. Bicarbonated Ringers solution (BRS) has shown promise due to its composition resembling human Extracellular Fluid and its potential benefits on hemodynamics., Objective: To evaluate the efficacy, mortality rates, hemodynamic effects, and adverse outcomes of Sodium Bicarbonate Ringer's Solution in the treatment of hemorrhagic shock, as compared to other relevant interventions., Method: A comprehensive examination of the available literature was performed by conducting systematic searches in prominent databases such as Cochrane, EMBASE, MEDLINE, and PubMed. The process employed predefined criteria to extract relevant data and evaluate the quality of the studies. The outcome measures considered encompassed survival rates, mortality, mean arterial pressure (MAP), heart rate (HR), and adverse events., Result: The meta-analysis of three studies showed that compared to the other crystalloids, the use of BRS had an odds ratio for survival of 1.86 (95% CI: 0.94, 3.71; p = 0.08; I 2  = 0%), an odds ratio for total adverse events of 0.14 (95% CI: 0.06, 0.35; p < 0.0001; I 2  = 22%), a mean difference in heart rate of -4.49 (95% CI: -7.55, -1.44; p = 0.004; I 2  = 13%), and a mean difference in mean arterial pressure of 2.31 (95% CI: -0.85, 5.47; p = 0.15; I 2  = 66%)., Conclusion: BRS demonstrated a significant reduction in complications, including adult respiratory distress syndrome (ARDS), Multiple Organ Dysfunction (MODS), and Total Adverse Effects, when compared to other solutions in the treatment of THS. Additionally, THS patients resuscitated with BRS experienced a notable decrease in heart rate. The findings suggest BRS may contribute to organ stability and potential survival improvement due to its similarity to human Extracellular Fluid and minimal impact on the liver., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)

This study aimed to explore the impact of different pH values of resuscitation fluid on traumatic hemorrhagic shock (THS), focusing on their effects on glycocalyx and inflammation. A rat model of THS was induced by hemorrhage from a left femur fracture, while an oxygen-glucose deprivation/reoxygenation (OGD/R)-induced HULEC-5a cell model was considered as an in vitro THS model. The lung tissue pathology and glycocalyx structure were assessed through hematoxylin-eosin (H&E) staining and transmission electron microscope examination. The levels of glycocalyx-related factors and inflammation-related factors were determined by enzyme-linked immunosorbent assay (ELISA). The expression of glycocalyx-related proteins, cell junction-related proteins, and proteins involved in the PI3K/Akt/NF-κB signaling pathway was analyzed by western blot. The results showed that both sodium bicarbonate Ringer's solution (BRS) and lactate Ringer's solution (LRS) were effective in restoring mean arterial pressure and heart rate in THS rats. However, LRS has a stronger impact on promoting inflammation and damaging the glycocalyx compared with BRS. In OGD/R-induced HULEC-5a cells, a pH of 7.4 and 6.5 increased inflammation and disrupted the glycocalyx, while a pH of 8.1 had no significant effect on inflammation or glycocalyx. Furthermore, the PI3K/Akt/NF-κB signaling pathway was activated by fluid resuscitation and different pH values. However, the activating effect of BRS and pH 8.1 on the PI3K/Akt/NF-κB signaling pathway was milder compared with LRS and pH6.5. In conclusion, an alkaline recovery environment was more beneficial for the treatment of THS., (© 2023 Wiley Periodicals LLC.)

Featured Application: A potential application of this work is in the corrosion and tribocorrosion behaviors of Ti alloys after surface modification. Ti alloys are prone to corrosion and wear due to the hostile environment in bodily fluids, but the Ti-45Nb alloy is considered to be a promising titanium alloy with excellent biocompatibility and resistance to physiological corrosion. In this study, Nb ions were implanted into a TA3 alloy and the effect on the biological corrosion as well as tribocorrosion behavior of TA3 in Ringer's solution was systematically investigated. The surface microstructure and XRD results revealed that the implanted samples showed a smoother surface due to the sputtering and radiation damages, and the Nb ions mainly existed in the alloy as the solid solution element. The electrochemical polarization tests showed that the implantation of Nb ions can increase the corrosion potential of the samples, showing a better thermodynamic stability. The tribocorrosion tests showed that the implanted samples exhibited a better thermodynamic stability in a corrosive environment accompanied by wear behavior, and the worn surface showed fewer pitting pits, indicating a better corrosion resistance. However, the abrasive wear and oxidation wear degree of the sample increased because of partial softening of the surface and brittle passivation film. [ABSTRACT FROM AUTHOR]

Background: The water volume of the endothelial glycocalyx layer has been estimated at 0.7 to 1.7 L using tracer methods of unclear value. The present study attempts to measure this fluid volume by analyzing the kinetics of a crystalloid fluid load. Methods: An intravenous infusion of approximately 1 L of Ringer's acetate was administered to 35 healthy volunteers, and the central volume of distribution of the water volume was calculated from the urinary excretion and frequent measurements of the fluid-induced hemodilution using mixed-effects modeling software. Comparisons were made with the plasma volume derived from three published anthropometric regression equations based on isotope measurements. In a second analysis, up to 2.5 L of Ringer's was administered to 60 volunteers selected from a cohort of 160 to have as similar hematocrits as possible to the volunteers whose data were used to create the anthropometric equations. Results: Volume kinetics showed that the infused crystalloid fluid occupied a larger central fluid space than was estimated with the isotope measurements. The first analysis of the 35 subjects indicated a mean difference of 0.51 L in males and 0.49 L in females. The second, larger analysis showed a mean excess volume of 0.43 L, which was approximately 15% of the circulating plasma volume. Conclusions: A crystalloid fluid load expands a 0.4–0.5 L larger central fluid space than the circulating plasma volume. The excess volume is probably located in the glycocalyx layer. [ABSTRACT FROM AUTHOR]

The wear resistance of a plate–screw tribo pair used to fix bone fractures was investigated using the pin-on-plate configuration under conditions of dry friction and friction in Ringer's solution. The nitrided and oxynitrided plates of Ti–6Al–4V titanium alloy in friction pairs with Fe–18Cr–10Ni–1Ti stainless steel were used. It was determined that under dry friction conditions, regardless of load, the nitrided Ti–6Al–4V titanium alloy provides a lower friction coefficient than the oxynitrided one; friction is implemented according to the adhesive wear mechanism. The use of Ringer's solution during friction tests leads to an adhesive–oxidative wear mechanism that decreases the friction coefficient in friction pairs of nitrided (oxynitrided) Ti–6Al–4V titanium alloy–Fe–18Cr–10Ni–1Ti stainless steel. In addition, the oxidative portion in the wear mechanism for an oxynitrided surface is greater, which decreases the adhesive wear in such a friction pair. [ABSTRACT FROM AUTHOR]

Among the ceramic materials available for load-bearing bioimplant applications, yttria-stabilized zirconia (Y-TZP) holds great potential owing to its superior mechanical properties (e.g., fracture toughness ~ 4.5 MPam1/2). However, the degradation concern of Y-TZP over long exposure to body fluids limits its applications. To overcome this limitation, the current work focuses on developing stabilized zirconia ceramics doped with Al2O3 and CeO2 through an easily available low-cost sintering technique. The microstructural, tribological, and degradation properties of Al2O3- and CeO2-doped 3Y-TZP bioceramic were investigated. The volumetric wear and roughness values of Al2O3- and CeO2-doped 3Y-TZP samples were found to be much lower compared to undoped 3Y-TZP samples. Relative densities of above 97.5% of the theoretical densities (> 6.1 g/cm−3) were obtained in 3Y-TZP sintered at 1450 °C. Low-temperature degradation resistance was observed when immersing the samples in Ringer's solution at 37 °C over a period of 24 weeks. The weight loss and SEM images of the samples were analyzed to generate the samples' degradation patterns. The results indicate that the incorporation of dopants is technically beneficial in terms of ceramic sample aging. [ABSTRACT FROM AUTHOR]