Fluid Concentrations Research Articles

Proteomics of plasma-derived extracellular vesicles reveals S100A8 as a novel biomarker for Alzheimer's disease: A preliminary study

Extracellular vesicles (EVs) act as mediators for intercellular transfer of Aβ and tau proteins, promoting the propagation of these pathological misfolded proteins throughout the brain in Alzheimer's disease (AD). Levels of blood exosomal Aβ42, total Tau (t-Tau) and phosphorylated Tau (p-Tau) had a high correlation with their concentrations in cerebrospinal fluid (CSF), demonstrating that exosomal biomarkers have equal contribution as those in CSF for the diagnosis of AD. We aimed to comprehensively characterize the proteome of plasma-derived EVs to identify differentially expressed proteins (DEPs) and pathways in AD. Tandem mass tag (TMT) labeled quantitative proteomics was applied to analyze plasma-derived EV proteins in 9 AD patients and 9 healthy controls. 335 proteins were quantified, and 12 DEPs were identified including seven upregulated proteins and five down-regulated proteins. Oligomerized Aβ1–42 induced SH-SY5Y cell damage model was built to mimic the pathological changes of AD, and small interfering RNA (siRNA) against S100A8 was used to knock down S100A8 expression. Results displayed S100A8 was down regulated in plasma-derived EVs from AD patients, while enriched in EVs derived from Aβ1–42-induced SH-SY5Y cells. Furthermore, Aβ1–42-induced SH-SY5Y cells treated with S100A8 siRNA showed decreased Aβ levels in cell lysate and EVs, especially in EVs. SignificanceThe investigation aimed to comprehensively characterize the proteome of plasma-derived EVs to identify DEPs and potential biomarker of AD. S100A8 was found down regulated in plasma-derived EVs from AD patients using TMT labeled quantitative proteomics. The diagnostic value of S100A8 was also confirmed using receiver operating characteristic curve (ROC) analysis. Furthermore, Aβ1–42-induced SH-SY5Y cells treated with S100A8 siRNA showed decreased Aβ levels in cell lysate and EVs, especially in EVs. The preliminary findings suggest that suppression of S100A8 expression inhibits Aβ aggregation both in cell lysate and EVs from Aβ1–42-induced SH-SY5Y cells, and S100A8 more likely regulates Aβ aggregation via EVs. Therefore, plasma-derived EV S100A8 might be a potential biomarker of AD. Manipulation of S100A8 expression may be a novel therapeutic strategy in the treatment of AD.

Design and optimization of an electrochemical sensor based on carbon nanotubes for the reliable voltammetric detection of serotonin in complex biological fluids

Serotonin concentration in peripherical biological fluids is correlated with the insurgence of several pathologies and represents valuable information on the human physical and mental state of health. Rapid, portable, and reliable electrochemical sensors can mine this useful information in real-time and in situ. However, the main challenge that hampers their implementation is the poor operational stability in biological fluids rich in bio-macromolecules, which can induce the fouling of the electrode altering or invalidating the analytical performance of the sensor. Herein, we propose the design of a reliable and robust voltammetric sensor for detecting serotonin in plasma. The sensor is based on multiwall carbon nanotubes modified with ligand-free gold nanoparticles obtained by metal vapor synthesis, which can efficiently catalyze the oxidation of serotonin. A thin layer of molecular imprinted polymer is added to provide selectivity and antifouling properties to the sensor. By applying a design of the experiment, to optimize the experimental condition of the differential pulsed voltammetry, and adsorptive stripping to selectively pre-accumulate serotonin in the artificial receptor, we achieved serotonin detection in plasma with sensitivity (6.7 μA μmol L−1 cm−2) and limits of detection (1.0 μmol L−1) comparable to those registered in phosphate buffer solution.

The effect of endocrine-disrupting chemicals in follicular fluid: The insights from oocyte to fertilization

Endocrine-disrupting chemicals (EDCs) exhibited the detriment in female reproductive health. Our objective was to investigate the individual and mixture effects of EDCs present in follicular fluid, the environment in which oocytes grow and develop, on early reproductive outcomes. We recruited 188 women seeking reproduction examination from the Study of Exposure and Reproductive Health (SEARCH) cohort between December 2020 and November 2021. We assessed the concentrations of 7 categories of 64 EDCs in follicular fluid, and measured early reproductive outcomes, including retrieved oocytes, mature oocytes, normal fertilized oocytes, and high-quality embryos. In this study Monomethyl phthalate (MMP) (2.17 ng/ml) were the compounds found in the highest median concentrations in follicular fluid. After adjusting for multiple testing, multivariate regression showed that multiple EDCs were significantly negatively associated with early assisted reproduction outcomes. For example, MMP showed a significant negative correlation with the number of high quality embryos (β: −0.1, 95 % CI: −0.15, −0.04). Specifically, eight types of EDCs were significantly negatively associated with four early assisted reproductive outcomes (β range: −0.2 ∼ -0.03). In the mixed exposure model, we found that mixtures of EDC were significantly negatively correlated with all four outcomes. In the quantile g-computation (QGCOMP) model, for each interquartile range increase in the concentration of EDC mixtures, the number of oocytes retrieved, mature oocytes, normally fertilized oocytes, and high-quality embryos decreased by 0.46, 0.52, 0.77, and 1.2, respectively. Moreover, we identified that phthalates (PAEs) predominantly contributed to the negative effects. Future research should validate our findings.

Customized flexible platform - starting point for the development of wearable sensor for the direct electrochemical detection of kynurenic acid in biological samples

Kynurenic acid (KA) is an active metabolite of tryptophan with notable biological effects, such as antioxidant, neuroprotective, and anti-inflammatory properties. It often undergoes changes of the concentration in biological fluids in chronic diseases. Thus, detecting KA is of great importance for diagnosing inflammatory and neurodegenerative conditions, monitoring disease progression, and assessing responses to pharmacological treatment.This study aimed to design a tailored, flexible platform for sensitive and direct electrochemical detection of KA in biological fluids. Carbon-based electrodes were custom-printed in the lab using specialized inks and flexible substrates. The working electrodes were further functionalized with graphene oxide and subsequently electrochemically reduced to increase the sensitivity toward the analyte. An optimized differential pulse voltammetry protocol was developed for KA detection. The elaborated platform was firstly characterized and then evaluated regarding the analytical performances. It showed a good limit of detection (3 nM and demonstrated the capability to detect KA across a broad concentration range (0.01–500 μM). Finally, the elaborated flexible platform, was succesfully applied for KA determination in serum and saliva samples, in comparison with an optimized HPLC-UV method.The developed platform is the first example of in-lab printed flexible platform reported in literature so far for KA detection. It is also the first study reported in the literature of detection of KA in raw saliva collected from 10 subjects. The sensitivity towards the target analyte, coupled with the adaptability and portability, showcases the potential of this platform for thus illustrating great potential for further development of wearable sensors and biomedical applications.

Synthetic Chemicals as Potential Tracers of Impacts of Fracturing Fluids on Groundwater

Application of hydraulic fracturing to produce “unconventional” oil and gas from shale formations and other low-permeability geological units has raised concerns about the potential environmental impacts, including potential adverse effects of fracturing fluids (FF) on groundwater. In this study, laboratory batch test experiments and new analytical methods were developed to analyze FF chemicals as potential indicators (tracers) to detect impacts of fracturing fluids on groundwater. The tests, conducted over 101–196 days, included FF with synthetic chemicals (~40,000–4,000,000 µg/L), placed in batches with groundwater and sediment at 5° and 25 °C, along with sterile controls. Using the new methods, measurable concentrations of the FF chemicals were many orders in magnitude lower (~3000 to 3,000,000 X) compared to their concentrations in synthetic fracturing fluids, indicating that these chemicals are excellent candidates as indicators of FF contamination in groundwater, if they are relatively persistent, and not prone to extensive loss by sorption during migration in the subsurface. Variable sorption and degradation of the chemicals was observed in both batch and column tests. Sorption was negligible (sorption coefficient, Kd~0.0) for some synthetic chemicals (polyethylene glycol, ethanolamines, isopropanol, and ethyl hexanol) in some tests. At the other extreme, strong sorption was observed for some of the higher molecular weight cocamido propyl betaine (max Kd = 1.17) and polyethylene glycol (max Kd = 1.12) components, and triethanolamine (max Kd = 0.47) in other tests. Apparent loss by degradation was observed for each chemical in some tests, but negligible in others. The shortest apparent half-lives were for isopropanol and ethyl hexanol at 25 °C (t½ < 11 days), and the most persistent synthetic chemicals were polyethylene glycols (t½ ≥ 182 d) and the ethanolamines (t½ ≥ 212 d). Of the potentially diagnostic FF chemicals investigated, the relatively hydrophilic and persistent lower molecular weight polyethylene glycols are some of the most promising as potential indicators of contamination of groundwater by FF.

Accuracy of gravity based automatic infusion system applied to chemoport for intravenous infusion.

191 Background: When a vesicant drug is administered to the peripheral vein, a gravity drip method rather than an peristaltic infusion pump is recommended. In addition, it is reported that the gravity based pump has less particle generation than the peristaltic pump that injects fluid through constant peristaltic movement. However, it is pointed out that the disadvantage of gravity based pump is that the rate of administration can easily change according to the change in the location of the injection site. We evaluate the accuracy of new gravity based pump (pressure-sensitive speed control fluid injection device, Accudrip made by Hanvit MD ) at various injection rates and hanging heights common to hospital settings. Methods: The accuracy and safety of the intravenous (IV) flow controller were evaluated for patients receiving IV chemotherapy in the oncology department. It was verified whether the accurate injection rate could be maintained even in various fluid heights, fluid amounts, and types of anticancer drugs that could affect the injection rate. Various anticancer drugs, including immune checkpoint inhibitor, were mixed with 250 ml/500 ml of normal saline and administered for 30 min/60 min, and glucose 500 ml/1000 ml was administered for 60 min/120 min to measure accuracy, each progressed 25 times. Medical staff were surveyed on the ease and limitations of medical practice for each peristaltic infusion pump and new gravity based pump. In addition, side effects occurring in patients during fluid administration were recorded. Results: The mean degree of error in the estimated end time of gravity based automatic infusion system was 3.09% (2.09 ~ 4.10). The error of the gravity based automatic infusion system was statistically significant depending on the patient age (p=.001) and the infusion time (p=.016), but the degree of error according to the type of fluids (p=.302) and fluid concentration (p=.844) was not statistically significant. Among the subjects of the study, nurses' satisfaction with the application of gravity based pump was 4.10 (±0.62) out of 5, and among the general characteristics of nurses, age ( p<.078), and working department (p<.91) did not show a statistically significant difference, but work experience ( p <.021) showed a statistically significant difference. Conclusions: The accuracy of Gravity based automatic infusion system was determined because the degree of error in the expected end time of infusion was not significant according to the infusion variable. In a survey of nurses who have used gravity based pump directly, it was found that the ease of use and satisfaction were similar to those of the conventional peristaltic pump. These findings will contribute greatly to the precise drug administration (over or under-administration) and minimization of adverse events in real-world hospital settings.

A Novel Electrochemical Method to Detect HIV in Saliva

Human Immunodeficiency Virus (HIV) is a global epidemic that causes acquired immunodeficiency syndrome (AIDS) with time. Approximately 14% (one in seven) of HIV-infected people do not know their HIV status till 2022 [1]. These people have a higher chance of spreading HIV without knowing its consequences. So, there is an unmet need for more HIV testing techniques to isolate and identify all HIV-infected people as soon as after their infection. Till now, there are no available techniques to detect HIV in saliva due to HIV’s low concentrations and the inhibition properties of saliva. We developed a nickel-based electrochemical method to detect HIV in saliva for the first time. This method does not require any biorecognition element for the detection, thus making it label-free. The difference in current responses during the chronoamperometry helps to distinguish HIV from saliva. It happens due to the blocking of the formation of NiOOH in the presence of HIV on the nickel surface. This method has high sensitivity and exhibits a linear current trend with increasing concentrations of HIV culture fluid. Also, it has a lower detection limit of around 50 copies/mL and a high selectivity of HIV over Epstein-Barr Virus (EBV), which is the most common co-infection for HIV patients. Also, the most common route to transmit EBV is through saliva. So, this novel method will create a new opportunity for the commercialization of non-invasive HIV testing techniques that minimize the spreading rate of HIV by fastening HIV testing.[1] “Global HIV & AIDS statistics — Fact sheet.” Accessed: Nov. 26, 2023. [Online]. Available: https://www.unaids.org/en/resources/fact-sheet

Solid-State Electrodes Towards a Real-Time Sensor Array for Health Monitoring

The healthcare industry has been transformed by advances in biotechnology, resulting in improved health outcomes. Central to this has been advances in medical diagnostics that can both monitor patients as well as provide actionable data at the point-of-care. However, further improvements are needed to maximize the utility of diagnostics at times where acute care may be required, such as when individuals are unstable after experiencing physical trauma. When medical resources are limited, the ability to rapidly and effectively triage patients that have experienced trauma is critical to maximizing health outcomes. Notably, individuals that have experienced significant trauma can degrade quickly. Therefore, continuous monitoring approaches are needed that can provide critical biometric and biomarker information that will enable updating of the triage in real-time.At present time, patients are assessed continuously using biometric monitoring. However, biometrics are often a lagging indicator to biochemical markers, and thus while easier to measure, less informative. Currently, the ISTAT-8 is a point-of-care unit to perform an automated, rapid biochemical panel that can assess the patient’s ability to maintain homeostasis by monitoring eight biomarkers. However, the ISTAT-8 captures biochemical data only at a point in time instead of continuously; this is a drawback, as the health of patients who have undergone trauma can improve or deteriorate rapidly. Therefore, a continuous biochemical monitoring solution is needed to allow for triage to happen in real-time.Advances in biotechnology have for the first time made real-time biochemical sensing a reality. Unfortunately, commercial continuous biochemical sensors to-date are limited to subcutaneous continuous glucose monitors (CGMs). CGMs monitor glucose concentrations in the interstitial fluid (ISF), which strongly correlates to blood values. While the CGM is now commonly used, the current devices are not easily multiplexed. Therefore, a scalable, easy to insert system is needed to perform multiplexed measurements; microneedle-based platforms have the promise to enable sensing in the ISF leveraging five or more distinct sensors.Here we present a solid-state platform that can enable multiplexed sensing leveraging hollow, wicking microneedles in fluidic contact with solid-state electrodes. Our approach leverages optimized sensor formulations and electrode materials fabricated onto a printed circuit board (PCB). The putative sensor array can be produced in a modular fashion leveraging scalable technologies and processes. Notably, this talk focuses on methods and approaches to fabricate an array of solid-state sensors that are capable of detecting ions and metabolites over extended periods (> 1 week) and can be readily integrated with microneedles for sensing interstitial fluid.

Evaluation of the Efficiency of Neural Enolase (NSA) in the Diagnosis of Viral Encephalitis: A Medical Review

Encephalitis is an inflammation that occurs in the brain when a virus in some cases, bacteria attack it directly, and can also be triggered by other factors. It is an inflammatory process of the meninges, the membranes that cover the central nervous system. Enolase isoenzyme found in neuronal and neuroendocrine tissues. Its levels in tissues other than erythrocytes are negligible. Its measurement is useful for monitoring tumors of neuroendocrine origin, such as neuroblastoma, pheochromocytoma, medullary thyroid carcinoma, small cell lung carcinoma, melanoma, and some pancreatic tumors. NSE concentrations in cerebrospinal fluid (CSF) are often elevated in diseases that result in relatively rapid neuronal destruction. This review aims to evaluate the efficiency of neural enolase (NSA) in diagnosing viral encephalitis. The methodology used an integrative literature review and a synthesis process to develop the study, expand the understanding of knowledge, and achieve the expected results. The integrative literature review is a method that aims to synthesize results obtained in research on a topic or issue, in a systematic, ordered, and comprehensive way. It is called integrative because it provides broader information on a subject/problem, thus constituting a body of knowledge. To carry out the study, a search for scientific articles was carried out through the Virtual Health Library, in the SCIELO, LILACS, and PUBMED databases, using the terminologies registered in the Health Sciences descriptors, encephalitis, enolase, virus, and diagnosis.

Associations between Non-Essential Trace Elements in Women's Biofluids and IVF Outcomes in Euploid Single-Embryo Transfer Cycles.

Previous studies have found inconsistent associations between heavy metals and metalloids (cadmium, lead, mercury, and arsenic), and reproductive outcomes. The biofluid concentrations of ten non-essential trace elements (Hg, Pb, As, Ba, Sr, Rb, Cs, Sn, Ni, and Co) were evaluated in 51 Spanish women undergoing ICSI, PGT-A, and SET/FET. Nine out of ten non-essential elements were detectable in follicular fluid, whole blood, and urine collected the day of vaginal oocyte retrieval (VOR) and the day of embryo transfer and then analyzed by ICP-MS or Tricell DMA-80 for mercury. Elevated mercury and strontium concentrations in follicular fluid were associated with poor ovarian response and preimplantation outcomes. Worst preimplantation outcomes were also identified in women with elevated whole-blood strontium or mercury, urinary arsenic, barium, and tin the day of VOR. High concentrations of urinary rubidium on VOR day were linked with enhanced fertilization and blastocyst development. Excessive titanium in whole blood was associated with lower odds of implantation, clinical pregnancy, and achieving a live birth in a given IVF cycle. Excessive urinary arsenic on the day of embryo transfer was associated with lower odds of live birth. Although these preliminary results need to be confirmed in larger populations, distinguishing organic and inorganic element forms, our findings show that some non-essential elements have a detrimental impact on human IVF outcomes.

Experimental and Theoretical Studies of Nano-Silica Solutions in Narrow Flow Paths Applied to Sealing Cement Cracks

Summary A cement crack is a typical cause of oil and gas well failure. Cracks weaken cement, reducing zonal isolation and fluid leakage. Nanoparticle (NP) gels are being tested for fracture treatment. When crushed into cracks, the flow behavior of NP problem solutions should be predicted. The potential efficacy of utilizing NP gels as a remedial measure for fractures is currently under investigation. It would be advantageous to determine if the flow behavior of solutions for NP problems can be anticipated when they are compressed into crevices. This study aimed to analyze the behavior of nano-silica solutions as they flow through ducts with rectangular cross-sections and varying crack dimensions. The introduction of NP solutions into the core leads to a decrease in pressure, which suggests that the nano-silica has been effectively transported through the crack. As the size of the fracture decreases, there is a corresponding increase in pressure drops, while the flow rate experiences a concurrent increase. This study presents responses of a pressure gradient to fluid concentration for a range of fracture widths, heights, and flow rates. The prediction of laminar flow in ducts is based on the linear correlation between the flow rate and the pressure gradient. Furthermore, the reduced pressure gradient indicates enhanced fluid flow within the fracture because of the amplified slot width. The fluid flow model proposed by Guo et al. (2022) was utilized to conduct a comparative analysis with the experimental data. Compared with test data, the model differs by roughly 90%. The technical cause of the flow model-observed data discrepancies is unknown. The flow model did not account for friction between NPs-NPs and NPs-walls in rough ducts. An empirical correlation has been found that quantifies the ratio as a function of nonsilica solution flow rate, cross-sectional geometry parameters, and nano-silica concentration. The correlation was calculated using nonlinear regression. The empirical relation and actual ratio have a significant correlation, as shown by R2 = 0.8965. In practice, Guo et al.’s (2022) hydraulic model’s pressure drops should be multiplied by the empirical correlation’s ratio to reduce errors.

Inertial drag combined with non‐uniform heat generation/absorption effects on the hydromagnetic flow of polar nanofluid over an elongating permeable surface due to the impose of chemical reaction

AbstractThe pivotal role of Brownian and thermophoresis in investigating the flow characteristic of polar nanofluid is important nowadays due to various engineering applications. The enhanced thermal and transport properties in the field of biomedical nanomedicine for hyperthermia treatments, and for enhancing the efficiency of heat exchange processes in cooling electronic devices, heat exchangers, and automotive engines the use of Brownian and thermophoresis is important. Therefore, the present study reveals the importance of Darcy–Forchheimer inertial drag combined with the space‐ and temperature‐dependent heat generation/absorption on the flow of polar nanofluid over an elongating surface. The surface is considered to be permeable for which the hydromagnetic flow in the presence of thermal radiation specifically, Brownian and thermophoresis affects the flow phenomena significantly. The proposed flow model designed with the aforementioned physical properties is standardized into the set of nonlinear ordinary equations by the implementation of suitable similarity rules. Further, the characteristics of various physical quantities are deployed by solving the system by using traditional Rung–Kutta fourth‐order technique. Further, the analysis of several factors is deployed briefly via graphically, and simulation of rate coefficients is presented through tables. The important outcomes of the study are deployed as the inclusion of thermal and solutal buoyancy enhances the velocity distribution, whereas reverse impact is observed for the increasing inertial drag. Also, space‐ and temperature‐dependent heat source augments the temperature profile but Lewis number decelerates the fluid concentration significantly.

Comparision of interleukin-1β concentrations in posttreatment endodontic disease and other pulpal and periapical conditions - A clinical study.

To evaluate interleukin (IL)-1β concentrations in periapical tissue fluid (PTF) in persistent apical periodontitis requiring endodontic retreatment and to compare the levels of IL-1β with chronic apical periodontitis, symptomatic irreversible pulpitis (SIP), normal pulpal, and periapical tissues. The patients were selected based on inclusion and exclusion criteria and divided into 4 groups based on the pulpal and periapical status: Posttreatment endodontic diseases (PTED): Teeth with PTED due to failed primary root canal treatment having periapical radiolucency. PNAP: Teeth requiring root canal treatment due to pulpal necrosis having periapical radiolucency. SIP: Teeth with symptoms of SIP with healthy periapical tissues). Intentional root canal treatment (IRCT): Teeth requiring IRCT (healthy pulp and periapical tissues). The access cavity was redefined and the preexisting filling was removed using H-files. The root canals were minimally enlarged followed by collection of PTF using paper points, in the case of group PTED. For groups PNAP, SIP, and IRCT, conventional access cavity preparation was done followed by enlargement of canals till 20, 0.02. PTF was collected using 15, 0.02 size absorbent points 2 mm beyond the apex. Levels of IL-1β was assessed by enzyme-linked immunosorbent assay. A statistically significant difference was seen in levels of IL-1β in all the groups. The highest concentration was seen in group PTED (85.07 ± 11.57 pg/mL) followed by group PNAP (37.60 ± 10.94 pg/mL), group SIP (8.40 ± 1.99 pg/mL), and the least was seen in group IRCT (3.47 ± 1.36 pg/mL). The levels of IL-1β were highest in PETD cases followed by PNAP, SIP, and IRCT. This indicates the severity of inflammation in PETD cases as compared to other endodontic diseases.

Numerical evaluation for the peristaltic flow in the proximity of double-diffusive convection of non-Newtonian nanofluid under the MHD

This article mainly studies the 2-D propagation of a non-compressible Eyring-Powell nanofluid flow through a stretched wedge under the Magneto-hydrodynamic effect. Equations for temperature, concentration, double-diffusive convection and momentum are taken into consideration. Since solving the dimensionless equations associated with our study is an uphill task, we utilize the MATLAB bvp4c solver to illustrate the graphical performance of different parameters. This manuscript may be significant in the projects in the field of industry and medicine. The manuscript's noteworthy features include the magnetic field, heat source-sink parameter, double diffusivity, and solar radiation process. The main finding is that the local fluid parameter k1 and magnetic field parameter M decelerate the velocity of nanofluid. Because different nanoparticles have different effects on fluids, the fluid's temperature exhibits multiple behaviors, therefore by escalating the Prandtl number initially, it increases and then decelerates due to the presence of nanoparticles. The concentration of fluid declines as the Schmidt number rises. The double diffusivity of Eyring-Powell nanofluid improves with magnification in the fluid's Schmidt number Sc and Prandtl number Pr.

Therapeutic drug monitoring of polymyxin B cerebrospinal fluid concentrations in patients with carbapenem-resistant Gram-negative bacteria-induced central nervous system infection.

Central nervous system (CNS) infections caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) present a major health and economic burden worldwide. This multicentre prospective study aimed to assess the feasibility and usefulness of CSF therapeutic drug monitoring (TDM) after intrathecal/intraventricular administration of polymyxin B in patients with CNS infections. Forty-two patients treated with intrathecal/intraventricular administration of polymyxin B against CR-GNB-induced CNS infections were enrolled. CSF trough level (Cmin) was collected beginning on Day 2 post-polymyxin B initiation and thereafter. The primary outcomes were clinical cure and 28-day all-cause mortality. All patients started with intrathecal/intraventricular administration of polymyxin B at a dose of 5 g/day, corresponding to a median CSF Cmin of 2.93 mg/L (range, 0.21-25.74 mg/L). Clinical cure was 71.4%, and the median CSF Cmin of this group was higher than that of clinical failure group [3.31 (IQR, 1.73-5.62) mg/L versus 2.25 (IQR, 1.09-4.12) mg/L; P = 0.011]. In addition, with MICs ≤ 0.5 mg/L, maintaining polymyxin B CSF Cmin above 2.0 mg/L showed a higher clinical cure rate (P = 0.041). The 28-day all-cause mortality rate was 31.0% and had no association with CSF Cmin. After intrathecal/intraventricular administration of polymyxin B, CSF concentrations fluctuated considerably inter- and intra-individual. Polymyxin B CSF Cmin above 2.0 mg/L was associated with clinical cure when MICs were ≤ 0.5 mg/L, and the feasibility of TDM warrants additional clinical studies.

Numerical simulation of a partially ionized Oldroyd-B nanofluid flow driven by two homocentric rotating disks with motile microorganisms

Nanofluids are assumed to be an excellent source of enhanced heat transfer with advanced thermophysical characteristics. Nanofluids are the backbone of the heating and cooling in the industrial processes. This research delves into the dynamics of a partially ionized Oldroyd-B nanofluid flowing between stretchable rotating disks. The study investigates heat transfer mechanisms incorporating a modified Fourier law and convective heat conditions. The viscoelastic fluid model presented here allows for the examination of relaxation and retardation times. Furthermore, the heat and mass transport of the Oldroyd-B nanofluid is characterized using a Buongiorno model, which considers thermophoresis and Brownian diffusion effects. Additionally, the study explores the impact of gyrotactic microorganisms in nanofluids, potentially enhancing environmental management strategies. The governing equations transform into dimensionless forms using Von Karman similarity variables. Numerical investigation of the anticipated model is conducted using the bvp4c scheme in MATLAB. The variation of different parameters in the dimensionless equations is illustrated through graphs and in tabulated format. The results indicate that increasing thermophoresis and Lewis numbers lead to a decrease in fluid concentration. Moreover, the temperature of the fluid rises at the lower disk and declines at the upper disk relative to the Biot number. The proposed model is validated through comparison with closely related published work.

Calcium carbonate crystallization process analysis on a heat transfer surface

This paper explores the growth process of calcium carbonate crystallization fouling on a heat surface using finite element methods to solve physical equations such as momentum, energy, and concentration diffusion, incorporating the impact of bulk crystallization on the concentration of scaling ions. The simulation uses deformation geometry, moving grids, and automatic re-meshing methods to study the dynamic growth of fouling layers and the spatiotemporal changes in fluid velocity, temperature, and concentration field-related parameters caused by it. Results indicate that the deposition interface temperature increases along the flow direction under constant heat flux conditions, leading to an increase in deposition rate. When the interface temperature exceeds 340 K, the fouling deposition rate becomes highly sensitive to temperature changes. The fouling thickness also increases along the flow direction, causing the heat transfer surface near the outlet to face a more severe heat transfer deterioration caused by scaling. Under constant temperature conditions, the deposition rate increases rapidly near the inlet and varies less along the flow direction. When the wall temperature remains constant, scaling is more likely to occur at the fluid inlet as the fluid temperature increases. This model also examines the effects of changes in the porosity of the fouling layer and ion interactions in composite salt solutions on the growth characteristics of the fouling layer.

Sex-specific associations of kynurenic acid with neopterin in Alzheimer’s disease

BackgroundSex differences in neuroinflammation could contribute to women’s increased risk of Alzheimer’s disease (AD), providing rationale for exploring sex-specific AD biomarkers. In AD, dysregulation of the kynurenine pathway (KP) contributes to neuroinflammation and there is some evidence of sex differences in KP metabolism. However, the sex-specific associations between KP metabolism and biomarkers of AD and neuroinflammation need to be explored further.MethodsHere we investigate sex differences in cerebrospinal fluid concentrations of seven KP metabolites and sex-specific associations with established AD biomarkers and neopterin, an indicator of neuroinflammation. This study included 311 patients with symptomatic AD and 105 age-matched cognitively unimpaired (CU) controls, followed for up to 5 years.ResultsWe found sex differences in KP metabolites in the AD group, with higher levels of most metabolites in men, while there were no sex differences in the CU group. In line with this, more KP metabolites were significantly altered in AD men compared to CU men, and there was a trend in the same direction in AD women. Furthermore, we found sex-specific associations between kynurenic acid and the kynurenic acid/quinolinic acid ratio with neopterin, but no sex differences in the associations between KP metabolites and clinical progression.DiscussionIn our cohort, sex differences in KP metabolites were restricted to AD patients. Our results suggest that dysregulation of the KP due to increased inflammation could contribute to higher AD risk in women.

ICTP concentration in cervical-vaginal fluid as a potential marker of membrane collagen degradation before labor.

Numerous physical and chemical processes lead to rupture of membranes. Within the fetal membranes there are numerous types of metalloproteinases, which cause collagen type I degradation. The C-terminal telopeptide of colagen type I (ICTP) is the breakdown product of type I collagen. The aim of the study was to determine whether ICTP is secreted into the vaginal-cervical fluid (VCF) in the case of physiological rupture of the membranes of the fetus before delivery. The study was conducted in March 2021 at the Department of Obstetrics and Perinatology of the Jagiellonian University in Cracow, Poland. Twenty-three cases were included in the study. During routine gynecological examination with the use of specula, VCF was collected twice in a volume of 50 µL. The obtained material was then subjected to enzyme immunoassay using the Human C-telopeptide of type I collagen (ICTP) ELISA Kit (Catalog Number. CSB-E10363h). The concentration of ICTP in the sample was calibrated. The concentration range that the device can detect was 25 ng /mL-800 ng/mL. The presence of ICTP in the VCF was confirmed. The minimum concentration was 43.72 ng/mL, the maximum was 762.59, in five cases the concentration was outside the maximum scale of the device. ICTP was confirmed in the VCF of pregnant women before physiological delivery. Further studies are required to accurately evaluate ICTP as a marker of the processes of collagen degradation in fetal membranes in the mechanism of physiological labor and premature rupture of the membranes.

Thiophene-based modified graphite electrode for the voltammetric detection of 2-aminoindane in oral fluid

New psychoactive substances, including 2-aminoindane, pose significant health risks due to their availability and structural similarity to amphetamines. Current detection methods are limited by lengthy analysis times and complex sample preparation. To address this, we present the first voltammetric determination of 2-aminoindane in oral fluid using a graphite electrode modified with a methoxyphenylthiophene-based layer. The electrochemically deposited layer was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and both infrared and Raman spectroscopies. After the electropolymerization of methoxyphenylthiophene, the electrode was homogeneously covered with shorter oligomers of the substituted polythiophene. Cyclic and square-wave voltammetry were used to gain insight into the interaction between the modified electrode and 2-aminoindane. The modification of the electrode surface enables to record the oxidation of the primary amino group at 0.85 V, with an additional signal assigned to specific interactions being observed at 1.33 V. Determination of a 1.0 × 10–4 M 2-aminoindane concentration in oral fluids was possible, with a recovery ranging from 98 to 100%.Graphical abstract