Applying Super-Resolution and Tomography Concepts to Identify Receptive Field Subunits in the Retina.

Spatially nonlinear stimulus integration by retinal ganglion cells lies at the heart of various computations performed by the retina. It arises from the nonlinear transmission of signals that ganglion cells receive from bipolar cells, which thereby constitute functional subunits within a ganglion cell's receptive field. Inferring these subunits from recorded ganglion cell activity promises a new avenue for studying the functional architecture of the retina. This calls for efficient methods, which leave sufficient experimental time to leverage the acquired knowledge for further investigating identified subunits. Here, we combine concepts from super-resolution microscopy and computed tomography and introduce super-resolved tomographic reconstruction (STR) as a technique to efficiently stimulate and locate receptive field subunits. Simulations demonstrate that this approach can reliably identify subunits across a wide range of model variations, and application in recordings of primate parasol ganglion cells validates the experimental feasibility. STR can potentially reveal comprehensive subunit layouts within only a few tens of minutes of recording time, making it ideal for online analysis and closed-loop investigations of receptive field substructure in retina recordings.

The sodium-bicarbonate cotransporter Slc4a5 mediates feedback at the first synapse of vision.

Feedback at the photoreceptor synapse is the first neuronal circuit computation in vision, which influences downstream activity patterns within the visual system. Yet, the identity of the feedback signal and the mechanism of synaptic transmission are still not well understood. Here, we combined perturbations of cell-type-specific genes of mouse horizontal cells with two-photon imaging of the result of light-induced feedback in cones and showed that the electrogenic bicarbonate transporter Slc4a5, but not the electroneutral bicarbonate transporter Slc4a3, both expressed specifically in horizontal cells, is necessary for horizontal cell-to-cone feedback. Pharmacological blockage of bicarbonate transporters and buffering pH also abolished the feedback but blocking sodium-proton exchangers and GABA receptors did not. Our work suggests an unconventional mechanism of feedback at the first visual synapse: changes in horizontal cell voltage modulate bicarbonate transport to the cell, via Slc4a5, which leads to the modulation of feedback to cones.

Attitudes and Barriers of Emergency Nurses and Physicians Toward Family Presence During Resuscitation in Iran: A Cross-Sectional Study.

INTRODUCTION: Implementing family presence during resuscitation poses many challenges in developing countries, especially in developing countries like Iran, where cultural and contextual factors play significant roles. This study examined the attitudes and barriers of Muslim emergency nurses and physicians toward family presence during resuscitation in Iran. METHODS: A cross-sectional study included 300 physicians and 500 nurses. Data were analyzed using descriptive and analytic statistics. RESULTS: The overall score of physicians' attitudes toward family presence during resuscitation was higher than nurses' (P = .001). Female nurses had a higher attitude score than male nurses (P = .001). Other demographic variables were not significant with nurses' attitudes toward family presence during resuscitation. The most significant barriers to family presence during resuscitation included increased stress on staff and unwanted events during cardiopulmonary resuscitation. The attitude of Iranian physicians and nurses toward family presence during resuscitation is becoming more positive, with more than half of them agreeing with both the concept and the practice. DISCUSSION: The findings suggest that hospitals should develop and adopt policies to ensure consistent performance when implementing family presence during resuscitation and that the procedure is safe and effective.

The landscape of clinical trials in corneal regeneration: A systematic review of tissue engineering approaches in corneal disease.

The limited availability of a healthy donor cornea and the incidence of allograft failure led researchers to seek other corneal substitutes via tissue engineering. Exploring the trend of clinical trials of the cornea with the vision of tissue engineering provides an opportunity to reveal future potential corneal substitutes. The results of this clinical trial are beneficial for future study designs to overcome the limitations of current therapeutic approaches. In this study, registered clinical trials of bio-based approaches were reviewed for corneal regeneration on March 22, 2024. Among the 3955 registered trials for the cornea, 392 trials were included in this study, which categorized in three main bio-based scaffolds, stem cells, and bioactive macromolecules. In addition to the acellular cornea and human amniotic membrane, several bio-based materials have been introduced as corneal substrates such as collagen, fibrin, and agarose. However, some synthetic materials have been introduced in recent studies to improve the desired properties of bio-based scaffolds for corneal substitutes. Nevertheless, new insights into corneal regenerative medicine have recently emerged from cell sheets with autologous and allogeneic cell sources. In addition, the future perspective of corneal regeneration is described through a literature review of recent experimental models.

Left atrial and ventricular deformation: alterations and predictive value of echocardiography parameters in end-stage renal disease patients after kidney transplantation.

Aims: End-stage renal disease (ESRD) patients are prone to alterations in cardiac haemodynamics specifically on the left ventricle (LV) and left atrial (LA) functions usually due to factors like uraemia, fluid overload, and inflammation. While studies on LV function in ESRD exist, research on LA function is limited. Successful kidney transplant (KTx) is believed to reverse pathological cardiac remodelling, and monitoring changes in cardiac strain before and after transplantation may guide pre- and post-transplant care. This study has two main objectives: to investigate alterations in LA and LV strain and other echocardiographic parameters after KTx and to identify independent factors predicting impaired strain parameters post-KTx. Methods and results: We conducted a prospective cohort study of 49 ESRD patients who underwent KTx. Echocardiography was performed at baseline and at 3 months after KTx. LV end-diastolic volume, LV end-systolic volume, LV end-diastolic diameter, LV ejection fraction (LVEF), E/e', maximum LA volume index (LAVi), LV global longitudinal strain (LVGLS), and all LA strain values, including booster (LASb), conduit (LAScd), and reservoir (LASr), improved significantly after KTx (P < 0.05). Regarding independent predictors of impaired LA and LV strains, pre-KTx values of LVEF, LAVi, and NT-proBNP were associated with LVGLS impairment after KTx; pre-KTx values of LAVi and LVEF were associated with LASr impairment after KTx. Conclusion: The present study provided valuable evidence on the effects of KTx on uraemic cardiomyopathy demonstrated by LA strain and LV strain improvements and indicated pre-KTx LVEF and LAVi as significant independent predictors of LVGLS and LASr impairment after KTx.

Correction: ECM-based bioadhesive hydrogel for sutureless repair of deep anterior corneal defects.

Correction for 'ECM-based bioadhesive hydrogel for sutureless repair of deep anterior corneal defects' by Safieh Boroumand et al., Biomater. Sci., 2024, https://doi.org/10.1039/d4bm00129j.

Improvement in right heart function following kidney transplantation in esrd patients: insights from speckle tracking echocardiography analysis.

Chronic kidney disease (CKD) is commonly associated with unfavorable cardiovascular outcomes and remains the leading cause of mortality in individuals with end-stage renal disease (ESRD). Despite substantial knowledge about the impact of CKD on the left heart, the right heart, which holds significant clinical relevance, has often been overlooked and inadequately assessed in ESRD patients who have undergone kidney transplant (KTx). This study aimed to evaluate the effects of KTx on the right heart chambers in ESRD patients. 57 adult KTx candidates were enrolled in this prospective longitudinal study, while 49 of them were included in the final assessment. Patients underwent a comprehensive cardiac assessment, including conventional echocardiography, speckle tracking echocardiography, and three-dimensional heart modeling both before and after surgery. Echocardiographic assessments showed significant increases in right ventricular (RV) ejection fraction, RV fractional area change (RVFAC), tricuspid annular plain systolic excursion, RV fractional shortening, right atrial (RA) reservoir, conduit, and booster strains, and RV global longitudinal strain (RVGLS). Moreover, significant reductions in RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), RV stroke volume, RV end-diastolic diameter (RVEDD) in mid-cavity view, systolic pulmonary artery pressure was observed (all P values < 0.05). However, no significant difference was found in S velocity, as well as RVEDD in basal and apex-to-annulus view. Moreover, pre-KTx measurements of RVGLS, RVEDD (apex-to-annulus diameter), RV fractional shortening, and S velocity were predictors of RVGLS after KTx. RA conduit strain was also identified as a predictor of RA conduit strain after KTx. Additionally, age, RVEDV, RVESV, RVFAC, and RA reservoir strain before KTx were identified as independent predictors of RA reservoir strain after KTx. The findings of this study demonstrate a significant improvement in right heart function following KTx. Furthermore, strain analysis can provide valuable insights for predicting right heart function after KTx.

ECM-based bioadhesive hydrogel for sutureless repair of deep anterior corneal defects.

Corneal transplantation is the gold standard treatment for corneal-related blindness; however, this strategy faces challenges such as limited donor cornea, graft rejection, suture-related complications, and the need for specialized equipment and advanced surgical skills. Development of tissue adhesives for corneal regeneration is of great clinical value. However, currently available corneal tissue sealants pose challenges, such as lack of safety, biocompatibility, and desired mechanical properties. To meet these requirements simultaneously, a bovine stromal corneal extracellular matrix (dCor) was used to design a bioadhesive photocurable hydrogel based on gelatin methacrylate (GelMA) and polyethylene glycol diacrylate (PEGDA) hydrogels (dCor/Gel-PEG). Integration of dCor into the dual networks of GelMA and PEGDA (Gel-PEG) led to a bioadhesive hydrogel for curing corneal defects, which could be crosslinked by Irgacure 2959 within 5 min ultraviolet irradiation. The viability of corneal stromal stem cells (CSSCs) was improved on the dCor/Gel-PEG hydrogel in comparison to the Gel-PEG hydrogel. The gene expression profile supported the keratocyte differentiation of CSSCs seeded on dCor/Gel-PEG via increased KERA and ALDH, with inhibited myofibroblast transdifferentiation via decreased α-SMA due to the presence of dCor. Interestingly, the dCor/Gel-PEG hydrogel exhibited favorable mechanical performance in terms of elasticity and bioadherence to the host corneal stroma. Ex vivo and in vivo examinations proved the feasibility of this hydrogel for the sutureless reconstruction of deep anterior corneal defects with promising histopathological results.

A Simple Non-Embedded Single Capillary Device for On-Demand Complex Emulsion Formation.

This study includes an examination of the design, fabrication, and experimentation of a rudimentary droplet generator. The device has potential applications in on-demand double and higher-order emulsions as well as tailored emulsions with numerous cores. The phenomenon of a pendant double droplet creation is observed when an inner phase is transported through a capillary, while a middle phase envelops the external surface of the capillary. This leads to the occurrence of a pinching-off process at the tip of the pulled capillary. Following this, the double droplet is introduced into a container that is filled with the outer phase. The present study examines the force equilibrium throughout the droplet break-up process and aims to forecast the final morphology of the droplets within the container by considering the impact of interfacial tension ratios. The shell thickness in a core-shell formation can be calculated based on the inner and middle phase flow rates as well as the middle droplet formation period. The present platform, which enables the simple production of double and higher emulsions, exhibits promising prospects for the controlled manufacturing of complex emulsions. This technology holds potential for various applications, including the experimental exploration of collision behavior or electro-hydrodynamics in emulsions as well as millimeter-size engineered microparticle fabrication.

Comparison of aloe vera gel dressing with conventional dressing on pressure ulcer pain reduction: a clinical trial.

BACKGROUND: Aloe Vera has a strong analgesic and anti-inflammatory effect, and its use effectively controls pain. This study aimed to determine the effect of Aloe Vera gel versus saline on pain relief of pressure ulcers. METHODS: This study is a double-blind, randomized clinical trial conducted in Valiasr Hospital in Arak, Markazi Province, in the center of Iran from May 2020 to April 2022. Using the available sampling method, 95 patients with pressure ulcers were assessed for eligibility, 64 patients were selected, 33 patients were placed in the experimental and 34 patients in control. For the experimental group, the ulcers were first cleaned with normal saline to remove the slough and then the already prepared Aloe Vera gel was evenly applied. For control groups, the ulcers were first washed with normal saline to remove off the slough and then covered with a sterile cotton gage, and the wound was tightly bandaged with a cotton roll to keep the "daily dressing" in place. A visual pain scale was used to assess the patient's pain level. Data analysis was done using SPSS 17. Descriptive statistics, ANOVA, and greenhouse tests were used. The significance level was 0.05. RESULTS: The results showed that the average pain score in both groups had a downward trend; that is, both dressings effectively reduced pressure ulcer pain (P < 0.001). The greenhouse test results showed that the difference between the two groups was significant (P < 0.001). CONCLUSION: The results showed the effect of Aloe Vera gel in reducing pressure ulcer pain. Dressing with Aloe Vera gel is preferable to reducing pain during dressing changes in patients with pressure ulcers. TRIAL REGISTRATION: Iranian Registry of Clinical Trials IRCT20180715040478N2, 2021-08-17.

Investigating the expression level of miR-17-3p, miR-101-3p, miR-335-3p, and miR-296-3p in the peripheral blood of patients with acute myocardial infarction.

The role of inflammation has been proven in acute myocardial infarction (AMI) pathogenesis. Due to the effect of NLRP3 gene expression in the inflammation process of MI, we aimed to explore the expression changes and diagnostic power of four inflammation-related miRNAs including miR-17-3p, miR-101-3p, miR-335-3p, miR-296-3p and their potential target, NLRP3, in ST-segment elevation myocardial infarction (STEMI), and non-STEMI (NSTEMI) patients as two major classes of AMI. The expression level of these genes were evaluated in 300 participants equally divided into three groups of STEMI, NSTEMI, and control using quantitative real-time PCR. The expression level of NLRP3 was upregulated in STEMI and NSTEMI patients compared to control subjects. Besides, the expression levels of miR-17-3p, miR-101-3p, and miR-296-3p were significantly downregulated in STEMI and NSTEMI patients compared to controls. The increased expression of NLRP3 had a very strong inverse correlation with miR-17-3p in patients with STEMI and with miR-101-3p in the STEMI and NSTEMI patients. ROC curve analysis showed that the expression level of miR-17-3p had the highest diagnostic power for discrimination between STEMI patients and controls. Remarkably, the combination of all markers resulted in a higher AUC. In summary, there is a significant association between the expression levels of miR-17-3p, miR-101-3p, miR-335-3p, miR-296-3p, and NLRP3 and the incidence of AMI. Although the miR-17-3p expression level has the highest diagnostic power to distinguish between STEMI patients and control subjects, the combination of these miRNAs and NLRP3 could serve as a novel potential diagnostic biomarker of STEMI.

Epidemiological, clinical, and economic burden of myocardial infarction patients in Iran during the COVID-19 pandemic.

Background: To define changes in AMI case rates, patient demographics, cardiovascular comorbidities, treatment approaches, in-hospital outcomes, and the economic burden of COVID-19 during the pandemic. Methods: We conducted a multicenter, observational survey with selected hospitals from three medical universities in Tehran city. A data collection tool consisting of three parts. The first part included socio-demographic information, and the second part included clinical information, major complications, and in-hospital mortality. Finally, the third part was related to the direct medical costs generated by AMI in COVID-19 and non-COVID-19 patients. The study cohort comprised 4,560 hospitalizations for AMI (2,935 for STEMI [64%] and 1,625 for NSTEMI [36%]). Results: Of those hospitalized for AMI, 1,864 (76.6 %) and 1,659 (78 %) were male before the COVID-19 outbreak and during the COVID-19 era, respectively. The length of stay (LOS), was significantly lower during the COVID-19 pandemic era (4.27 ± 3.63 vs 5.24 ± 5.17, p = 0.00). Results showed that there were no significant differences in terms of patient risk factors across periods. A total of 2,126 AMIs were registered during the COVID-19 era, with a 12.65 % reduction (95 % CI 1.5-25.1) compared with the equivalent time in 2019 (P = 0.179). The risk of in-hospital mortality rate for AMI patients increased from 4.9 % in 2019 to 7.0 % in the COVID-19 era (OR = 1.42; 95 % CI 1.11-1.82; P = 0.004). Major complications were registered in 9.7 % of cases in 2020, which is higher than the rate of 6.6 % reported in 2019 (OR = 1.46, 95 % CI 1.11-1.82; P = 0.000). Total costs in hospitalized AMI-COVID patients averaged $188 more than in AMI patients (P = 0.020). Conclusion: This cross-sectional study found important changes in AMI hospitalization rates, worse outcomes, and higher costs during the COVID-19 periods. Future studies are recommended to examine the long-term outcomes of hospitalized AMI patients during the COVID-19 era.

Response surface methodology (RSM) for optimizing ozone-assisted process parameters for formaldehyde removal.

Formaldehyde, a volatile organic compound (VOC), is one of the main gaseous pollutants from commercial cooking. The present study evaluated the effectiveness of a laboratory-scale ozone-assisted indirect plasma method for formaldehyde removal using response surface methodology (RSM). A dielectric barrier discharge (DBD) reactor was used for ozone generation. Inlet HCHO concentration, ozone concentration, and residence time were considered the design parameters, and formaldehyde removal efficiency (response 1) and energy yield (response 2) were considered response parameters. The optimized models showed a positive correlation between the predicted and experimental outcomes. Inlet ozone concentration, the most significant parameter in the removal efficiency model, represented a positive correlation with this response in most parts of the operating region. The optimal point with the highest desirability (i.e., D1 point) was obtained at the inlet HCHO concentration of 120 ppm, inlet ozone concentration of 40 ppm, and reaction time of 11.35 s within the parameter ranges studied, resulting in 64% removal efficiency and 2.64 g/kWh energy yield. At the point with the second highest desirability (D2), 100% removal efficiency along with 0.7 g/kWh energy yield was achieved indicating the very good performance of the process. The indirect plasma approach used in this study presented a successful performance in terms of removal efficiency along with acceptable energy yield compared to other plasma-assisted processes reported in the literature. The results suggested that ozone-assisted indirect plasma treatment can be utilized as an efficient alternative method for formaldehyde removal in commercial kitchens, while efficiency or energy yield should be prioritized for optimizing operating conditions.

Evaluation of Systolic Function using Global Longitudinal Strain in Isolated Obese and Overweight People.

BACKGROUND: The association of obesity with left ventricular (LV) diastolic dysfunction is fully understood, but there are few investigations regarding its effect on LV systolic function in the absence of other risk factors. This study aimed to identify the global longitudinal strain (GLS) changes in isolated overweight and obese people in the absence of other risk factors. METHODS: A total of 120 individuals, including 60 obese, 30 overweight, and 30 healthy controls with no underlying disease and no history of hypertension, diabetes, CAD, or CKD were included in the study. Echocardiographic findings were measured, including apical 2-, 3- and 4-chamber GLS, GLS total, LV diameter, interventricular septum thickness, and PAP. These findings were then compared between the three groups (obese, overweight, and normal controls). RESULTS: Analyses showed that LV diameter in healthy controls was significantly lower compared to overweight (p = 0.02) and obese (p < 0.0001) participants. Also, the interventricular septal thickness was significantly increased in overweight (p = 0.007) and obese (p < 0.0001) individuals compared to healthy controls. The mean and standard deviation (Mean ± SD) of total GLS values were - 22.29% ± 1.89% for normal weight, -22.09% ± 1.91% for overweight, and -19.88% ± 2.34% for obese individuals. The total GLS of obese participants was significantly lower than overweight and normal controls (p < 0.0001). It was observed that the GLS values were significantly lower in people with BMI higher than 40. The mean ± SD of total GLS values were -20.68% (1.84%) for BMI ≤ 40 patients and -18.51% (2.52%) for BMI > 40 patients. CONCLUSION: Data revealed that all GLS values had a moderately strong correlation with BMI values. Also, subclinical LV dysfunction was detected in overweight and obese subjects.

Trivalvular nonbacterial thrombotic endocarditis in a patient with colon adenocarcinoma: a case report.

BACKGROUND: Nonbacterial thrombotic endocarditis is a rare complication of prothrombotic states such as neoplasms that can cause valvular dysfunction and life-threatening complications. Nonbacterial thrombotic endocarditis usually affects the left-sided valves; however, only a minority of cases involving the tricuspid valve have been reported in medical literature. CASE PRESENTATION: The current report describes trivalvular involvement by nonbacterial thrombotic endocarditis in a 54-year-old Azeri female patient with metastatic colorectal carcinoma. This case underlines the necessity of evaluating nonbacterial thrombotic endocarditis as a possible consequence in cancer patients. When thromboembolic events are found in the presence of a hypercoagulable state (such as malignancy) and no growth on blood cultures, nonbacterial thrombotic endocarditis could be suspected as the cause. CONCLUSION: It is critical to achieve early diagnosis in such a setting to initiate treatment plans and prevent further complications rapidly.

Nanoscale vibration could promote tenogenic differentiation of umbilical cord mesenchymal stem cells.

Regulation of mesenchymal stem cell (MSC) fate for targeted cell therapy applications has been a subject of interest, particularly for tissues such as tendons that possess a marginal regenerative capacity. Control of MSCs' fate into the tendon-specific lineage has mainly been achieved by implementation of chemical growth factors. Mechanical stimuli or 3-dimensional (D) scaffolds have been used as an additional tool for the differentiation of MSCs into tenocytes, but oftentimes, they require a sophisticated bioreactor or a complex scaffold fabrication technique which reduces the feasibility of the proposed method to be used in practice. Here, we used nanovibration to induce the differentiation of MSCs toward the tenogenic fate solely by the use of nanovibration and without the need for growth factors or complex scaffolds. MSCs were cultured on 2D cell culture dishes that were connected to piezo ceramic arrays to apply nanovibration (30-80 nm and 1 kHz frequency) over 7 and 14 d. We observed that nanovibration resulted in significant overexpression of tendon-related markers in both gene expression and protein expression levels, while there was no significant differentiation into adipose and cartilage lineages. These findings could be of assistance in the mechanoregulation of MSCs for stem cell engineering and regenerative medicine applications.

Diversity of Ganglion Cell Responses to Saccade-Like Image Shifts in the Primate Retina.

Saccades are a fundamental part of natural vision. They interrupt fixations of the visual gaze and rapidly shift the image that falls onto the retina. These stimulus dynamics can cause activation or suppression of different retinal ganglion cells, but how they affect the encoding of visual information in different types of ganglion cells is largely unknown. Here, we recorded spiking responses to saccade-like shifts of luminance gratings from ganglion cells in isolated marmoset retinas and investigated how the activity depended on the combination of presaccadic and postsaccadic images. All identified cell types, On and Off parasol and midget cells, as well as a type of Large Off cells, displayed distinct response patterns, including particular sensitivity to either the presaccadic or the postsaccadic image or combinations thereof. In addition, Off parasol and Large Off cells, but not On cells, showed pronounced sensitivity to whether the image changed across the transition. Stimulus sensitivity of On cells could be explained based on their responses to step changes in light intensity, whereas Off cells, in particular, parasol and the Large Off cells, seem to be affected by additional interactions that are not triggered during simple light-intensity flashes. Together, our data show that ganglion cells in the primate retina are sensitive to different combinations of presaccadic and postsaccadic visual stimuli. This contributes to the functional diversity of the output signals of the retina and to asymmetries between On and Off pathways and provides evidence of signal processing beyond what is triggered by isolated steps in light intensity.SIGNIFICANCE STATEMENT Sudden eye movements (saccades) shift our direction of gaze, bringing new images in focus on our retinas. To study how retinal neurons deal with these rapid image transitions, we recorded spiking activity from ganglion cells, the output neurons of the retina, in isolated retinas of marmoset monkeys while shifting a projected image in a saccade-like fashion across the retina. We found that the cells do not just respond to the newly fixated image, but that different types of ganglion cells display different sensitivities to the presaccadic and postsaccadic stimulus patterns. Certain Off cells, for example, are sensitive to changes in the image across transitions, which contributes to differences between On and Off information channels and extends the range of encoded stimulus features.

Ce(III) and La(III) ions adsorption using Amberlite XAD-7 resin impregnated with DEHPA extractant: response surface methodology, isotherm and kinetic study.

In this paper, the removal efficiency of Cerium (Ce(ΙΙΙ)) and lanthanum (La(ΙΙΙ)) ions from aqueous solution using Amberlite XAD-7 resin impregnated with DEHPA(XAD7-DEHPA) was studied in the batch system. The adsorbent ( XAD7-DEHPA) was characterized by SEM-EDX, FTIR and BET analysis Techniques. The response surface methodology based on the central composite design was applied to model and optimize the removal process and evaluate operating parameters like adsorbent dose (0.05-0.065), initial pH (2-6) and temperature (15-55). Variance analysis showed that the adsorbent dose, pH and temperature were the most effective parameters in the adsorption of Ce(ΙIΙ)and La(IΙI) respectively. The results showed that the optimum adsorption condition was achieved at pH = 6, the optimum amount of absorbent and the equilibrium time equal to 0.6 gr and 180 min, respectively. According to the results, the adsorption percentage of Ce(ΙIΙ) and La(ΙΙΙ) ions onto the aforementioned resin were 99.99% and 78.76% respectively. Langmuir, Freundlich, Temkin and sips isotherm models were applied to describe the equilibrium data. From the results, Langmuir isotherm (R2 (Ce) = 0.999, R2 (La) = 0.998) was found to better correlate the experimental rate data. The maximum adsorption capacity of the adsorbent ( XAD7-DEHPA) for both Ce(IΙI) and La(III) was found to be 8.28 and 5.52 mg g-1 respectively. The kinetic data were fitted to pseudo-first-order, pseudo-second-order and Intra particle diffusion models. Based on the results, the pseudo-first-order model and Intra particle diffusion model described the experimental data as well. In general, the results showed that ( XAD7-DEHPA) resin is an effective adsorbent for the removal of Ce(IΙI) and La(III) ions from aqueous solutions due to its high ability to selectively remove these metals as well as its reusability.

Computational fluid dynamics simulation of two-phase flow patterns in a serpentine microfluidic device.

In the current research work, the flow behavior of a liquid-liquid extraction (LLE) process in a serpentine microchannel was analyzed. The simulation was performed using a 3D model and the results were found to be consistent with experimental data. The impact of the flow of chloroform and water on the flow model was also examined. The data indicate that once the aqua and organic phases flow rates are low and similar, a slug flow pattern is observed. However, as the overall flow rate raises, the slug flow transforms into parallel plug flow or droplet flow. An increment in the aqua flows while maintaining a constant organic phase flow rate results in a transition from slug flow to either droplet flow or plug flow. Finally, the patterns of flow rate in the serpentine micro-channel were characterized and depicted. The results of this study will provide valuable insights into the behavior of two-phase flow patterns in serpentine microfluidic devices. This information can be used to optimize the design of microfluidic devices for various applications. Furthermore, the study will demonstrate the applicability of CFD simulation in investigating the behavior of fluids in microfluidic devices, which can be a cost-effective and efficient alternative to experimental studies.

Ce(ΙΙΙ) and La(ΙΙΙ) ions adsorption through Amberlite XAD-7 resin impregnated via CYANEX-272 extractant.

The goal of this paper is to investigate the ability of Amberlite XAD-7 (AXAD-7) resin impregnated with CYANEX-272 (di-2,4,4-trimethylpentyl phosphonic acid) to remove cerium (Ce(ΙΙΙ)) and lanthanum (La(ΙΙΙ)) ions from aqueous solutions in the batch scheme. The prepared adsorbent material was determined utilizing FTIR, SEM-EDX, and BET methods. The impact of three individual process variable factors involving feed solution pH (2-6), adsorbent dose (0.05-0.65), and process temperature (15-55 °C) on the simultaneous removal of Ce(ΙΙΙ) and La(ΙΙΙ) ions was evaluated via response surface methodology (RSM) according to the central composite design (CCD). The modeling of Ce(ΙΙΙ) and La(ΙΙΙ) ions adsorption was performed using the quadratic model and was evaluated using a coefficient of determination for both ions. The optimization data revealed that the adsorption amount of Ce(ΙΙΙ) and La(ΙΙΙ) ions removal under optimal conditions were 99.75% and 69.98%, respectively. Equilibrium and kinetic investigations were also conducted to define the removal performance of the calculated adsorbent for Ce(ΙΙΙ) and La(ΙΙΙ) ions removal. Various isotherms models such as Langmuir, Freundlich, Temkin, and Sips were examined at 25 °C to analyze the equilibrium isotherm data. The data revealed that the Sips approach is compatible with the experimental data. The highest adsorption capacity of the resin for Ce(ΙΙΙ) and La(ΙΙΙ) ions were 11.873 mg g-1 and 7.324 mg g-1, correspondingly. The kinetic study of the Ce(ΙΙΙ) and La(ΙΙΙ) adsorption process was conducted via pseudo-first-order, pseudo-second-order, and intraparticle diffusion models(IDMs). Based on the data obtained, kinetic data were fitted well to a pseudo-second-order rate correlation. According to the obtained results, the (AXAD-7) resin impregnated with CYANEX-272 performed well in removing both Ce(ΙΙΙ) and La(ΙΙΙ) ions from aqueous solutions with well stability during several adsorption-desorption cycles and well regeneration and excellent metallic ions recovery.