Solute Exchange Research Articles

Technology Focus: Production and Facilities (December 2024)

This year has been both inspiring and exhilarating in the production and facilities domain, highlighted by a record 269 abstracts. This plethora of ideas fosters industry knowledge and promotes the exchange of innovative solutions driven by engineering advancements and data analytics. It covers the deployment of digital technologies, the journey toward decarbonization and its environmental impact, and the enhancement of energy efficiency and maintenance of asset integrity. The process of reviewing a significant number of technical abstracts based on their relevance, originality, clarity, and potential impact on the oil and gas industry is essential to ensure that JPT’s readers see papers with high-quality contributions to the production and facilities community. Comprehensive digital solutions cover the entire spectrum of production and facilities management, integrating a wide range of technologies such as advanced data analytics, Internet of Things devices, artificial intelligence, machine learning, cloud computing, automation, robotics, and digital twins. To exemplify this, paper OTC 32872 outlines learnings by evaluating the routine of a floating production, storage, and offloading vehicle crew to identify scenarios for the application of ground robots in day-to-day offshore activities, leading to a boost in productivity while reducing human exposure to risk. In the field of minimizing carbon footprint and promoting environmental sustainability, several academic papers have outlined strategies for reducing emissions led by a creative ecosystem of technologies and solutions, encompassing the deployment of methane emissions quantification at production facilities, reducing gas flaring, enhancing energy efficiency, repurposing of existing gas pipeline networks for the transport of hydrogen and hydrogen/methane blend, and using hydrogen fuel in a dual-fuel engine on a drilling rig. A notable illustration is URTeC paper 3866061, which presents continuous-monitoring point sensors for methane emissions, tracking changes in parts per million of methane in the air. Collecting raw data and applying a proprietary data-science algorithm, using a plume-dispersion model with the continuously acquired data, the evidence is reported to the operator, identifying the piece of equipment from which emissions originate and quantifying the volume and rate of the emission. In the asset-integrity-management landscape, the integration of digital technologies is playing a key role, whether through machine learning and artificial intelligence paired with fiber-optic distributed acoustic sensing technologies used to enhance pipeline integrity or rapid and reliable management of pipeline leak detection with a novel method on a multiphase-flow leak-detection model using only input and output parameters. From the standpoint of composite and nonmetallic materials, ongoing product research, development, and qualification efforts are being pursued to meet rising demand to stretch the operational envelope and enhance reliability. With the rapid advancement of carbon capture use and storage wells, paper SPE 217664 provides a guideline for such selections based on the composition of the CO2 stream, including impurities and the composition of the saline formation into which the CO2 will be injected. Recommended additional reading at OnePetro: www.onepetro.org. SPE 216229 Resource Optimization at Remote Facilities by Leveraging Advance Maintenance Practices Total Productive Maintenance, Operator-Driven Reliability, and Industry 4.0 Technologies by Muhammad Shahzad Ahmed, ADNOC, et al. OTC 34661 Unleashing the Sky Potential: Revolutionizing Construction With Drones by Chen Khian Fong, Shell, et al. SPE 217716 World’s First Demonstration of Hydrogen Blending in Dual-Fuel Engines on a Drilling Rig by W. Kernan, Caterpillar, et al.

Identifying solute loss from karst conduit to fissures under concentrated recharge conditions

The aquifer within karst areas exhibits significant heterogeneity, accompanied by intricate runoff processes and swift hydrological responses. The solute transport process within karst conduits is influenced by various factors, including karst development characteristics and variations in hydrodynamic conditions, thereby displaying a high level of complexity. This complexity plays a crucial role in governing the safe utilization of karst water resources and the prevention of groundwater pollution. In this paper, a typical karst conduit system in southern China is chosen to investigate the influence mechanism of hydrodynamic conditions on the solute transport process within the karst conduit. This investigation is conducted through multiple sets of field artificial tracer tests. An intriguing phenomenon was observed: When the mean flow velocity of the conduit flow is either low (<200 m/h) or high (>1000 m/h), the solute concentrations and recovery rates are low. Conversely, the solute concentration and recovery rate are highest at a medium flow velocity (560 m/h), with the recovery rates ranging from 0.13 % to 92.44 %. A theoretical formula has been derived to estimate the solute loss from conduit flow to fissure flow. When the conduit is filled with water, an increase in the mean flow velocity leads to an augmentation in the amount of water recharged from the conduit into the fissures, as well as an increase in the stored solute mass, which results in a decrease in the solute recovery rate. The condition that poses the highest risk of groundwater pollution occurs at a medium flow velocity, where the solute concentration and recovery rate are all at their maximum levels. When the recharge rate at the sinkhole is very small, both the cross-sectional area and the mean flow velocity of the karst conduit are reduced. The rough bottom of the karst conduit leads to an increase in dispersivity, resulting in low solute concentration and recovery rate. The results elucidate the reasons behind the significant variations in solute recovery rates under different hydrodynamic conditions. They provide novel evidence for comprehending the water and solute exchange processes between conduits and fissures under concentrated recharge conditions. Furthermore, these findings offer a valuable reference for assessing the risk of groundwater pollution in karst areas.

Efficient and highly amplified imaging of nucleic acid targets in cellular and histopathological samples with pSABER.

In situ hybridization (ISH) is a powerful tool for investigating the spatial arrangement of nucleic acid targets in fixed samples. ISH is typically visualized using fluorophores to allow high sensitivity and multiplexing or with colorimetric labels to facilitate covisualization with histopathological stains. Both approaches benefit from signal amplification, which makes target detection effective, rapid and compatible with a broad range of optical systems. Here, we introduce a unified technical platform, termed 'pSABER', for the amplification of ISH signals in cell and tissue systems. pSABER decorates the in situ target with concatemeric binding sites for a horseradish peroxidase-conjugated oligonucleotide, enabling the localized deposition of fluorescent or colorimetric substrates. We demonstrate that pSABER effectively labels DNA and RNA targets in cultured cells and FFPE specimens. Furthermore, pSABER can achieve fivefold signal amplification over conventional signal amplification by exchange reaction (SABER) and can be serially multiplexed using solution exchange. Therefore, by linking nucleic acid detection to robust signal amplification capable of diverse readouts, pSABER will have broad utility in research and clinical settings.

Loss of aquaporin-4 impairs cerebrospinal fluid solute clearance through cerebrospinal fluid drainage pathways

The aquaporin-4 (AQP4) water channel is essential in neurofluid dynamics. AQP4 loss impairs solute exchange between the cerebrospinal fluid (CSF) and interstitial fluid (ISF). However, whether AQP4 expression affects solute clearance from the CSF space to the extracranial space remains unclear. This study aimed to investigate this using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) following the intrathecal administration of gadolinium-based contrast agents (GBCAs) to AQP4 knockout (KO) rats. AQP4 KO rats showed reduced efflux of intrathecal GBCAs to the extracranial spaces through CSF drainage pathways and increased retention of intrathecal GBCAs in the CSF space compared with the controls. These results suggest that AQP4 loss impairs solute clearance from the CSF space to the extracranial spaces via the CSF drainage pathways. This study revealed a close relationship between AQP4 expression and CSF solute clearance, contributing to a better understanding of the function of AQP4 in neurofluid dynamics.

Influence of Evaporation and High‐Frequency Seawater Inundation on Salinity Dynamics in Swash Zones

AbstractThe interactions between the atmosphere, ocean, and beach in the swash zone are dynamic, influencing water flux and solute exchange across the land‐sea interface. This study employs groundwater simulations to examine the combined effects of waves and evaporation on subsurface flow and salinity dynamics in a shallow beach environment. Our simulations reveal that wave motion generates a saline plume beneath the swash zone, where evaporation induces hypersalinity near the sand surface. This leads to the formation of a hypersaline plume beneath the swash zone during periods of wave recession, which extends vertically downward to a maximum depth of 30 cm, driven by the resulting vertical density gradients. This hypersaline plume moves approximately 2 m landward to the top of the swash zone and down the beachface due to wave‐induced seawater infiltration and is subsequently diluted by the surrounding saline groundwater. Furthermore, swash motion increases near‐surface moisture, leading to an elevated evaporation rate, with dynamic fluctuations in both moisture and evaporation rate due to high‐frequency surface inundation caused by individual waves. Notably, the highest evaporation rates on the swash zone surface do not always correspond to the greatest elevations of salt concentration within the swash zone. This is because optimal moisture is also required—neither too low to impede evaporation nor too high to dilute accumulated salt near the surface. These insights are crucial for enhancing our understanding of coastal groundwater flow, biogeochemical conditions, and the subsequent nutrient cycling and contaminant transport in coastal zones.

Biofilm Growth in Porous Media Well Approximated by Fractal Multirate Mass Transfer With Advective‐Diffusive Solute Exchange

AbstractBiofilm growth in porous media changes not only the hydrodynamic properties of the medium (reduction in porosity and permeability, and increase in dispersivity), but also the transport itself (breakthrough curves display increasingly fast first arrivals and long tails). These features are well reproduced by multicontinuum models (Multi‐Rate Mass Transfer, MRMT) which can be used to describe reactive transport in heterogeneous porous media and facilitate the simulation of reactions that are localized within biofilms. Here, we present a conceptual and numerical model of biochemical reactive transport with dynamic biofilm growth based on MRMT formulations. Mass exchange between mobile water and immobile biofilm aggregates is represented by a memory function, which simplifies definition of MRMT parameters. We successfully tested this model on two sets of laboratory data and found that (a) a basic model based on the growth of uniformly sized biofilm aggregates fails to reproduce laboratory tracer tests and rate of biofilm growth, while a fractal growth model, which we obtain by integrating the memory functions of biofilm aggregates with a power law distribution, does; (b) the biofilm memory function evolves as the biofilm grows; and (c) the early time portion of eluted volume tracer breakthrough curves are independent of flow rate, whereas the tail becomes heavier when the flow rate is decreased, which implies that both advection controlled and diffusion controlled mass exchange coexist in biofilms. These findings imply that porous media biofilms are essentially different from those developing in human tissues or open spaces.

The Power of Hidden Teams: Leveraging Informal Relationships to Drive Organizational Success

This article explores the importance of informal networks, or "hidden teams", that exist within organizations alongside formal hierarchical structures, as research has shown these organic relationship-based networks play a key role in knowledge sharing, innovation, and driving work forward through efficient exchange of ideas and solutions across boundaries in communities of practice and "invisible colleges", while teams that bridge different professional communities are better able to solve complex problems. The article provides recommendations for how leaders can identify, support, and leverage hidden teams to drive business success by mapping networks through analysis and employee surveys to uncover natural collaborations, supporting hidden teams through dedicating time and space for collaboration, cross-pollinating memberships, institutionalizing information flows, and recognizing contributions, as demonstrated through two case studies where a technology company and healthcare system identified existing hidden teams, formalized roles and support, and achieved rapid, grassroots change and meaningful business impacts, suggesting that viewing informal networks as assets that break down silos and strengthen connections across groups can empower change and improve organizational performance.

Differences in Changes of Mobility Patterns Across the Globe—Evidence From a Natural Experiment

ABSTRACTThe impact of population mobility and transportation choices on the environment is significant. Sustainable mobility policies require an understanding of evolving mobility patterns. This study examines global mobility variations across countries using COVID‐19 Community Mobility Reports. Employing the k‐medoids algorithm and Dynamic Time Warping, we analyzed mobility dynamics. Results reveal diverse changes in population mobility. Around 52 Global North countries exhibit approximately 10% reduction in professional activity‐related traffic post‐COVID‐19. Regarding urban green space mobility, only 29 countries exhibit strong seasonality, with summer traffic in the northern hemisphere peaking at about 150% higher than winter traffic. Three groups of countries are identified concerning public transport mobility: returning to pre‐pandemic levels, experiencing a 25% increase, and nearly doubling from pre‐pandemic levels. This underscores the key determinants for sustainable mobility policy implementation. Fifteen highly developed countries share similar mobility patterns across six areas studied, facilitating the exchange of sustainable mobility solutions and best practices. This research underscores the importance of understanding and addressing evolving mobility patterns for effective environmental policy planning.

Ultralong Room Temperature Phosphorescence Emission From Gels Induced by Multiple Confinement Effects

AbstractThe construction of ultra‐long room temperature phosphorescence (RTP) gels has always been a serious challenge because the dispersing medium would significantly deteriorate their rigidity, resulting in triplet excitons consumption by non‐radiative transitions. In this paper, eutectogel with ultra‐long RTP emission is successfully constructed by rebuilding the damaged rigid system with solvent exchange. Specifically, the formation of cyclic borate via the B─O click reaction between 1,3,5‐tris(4‐phenylboronic acid)benzene (TPPB) and poly(vinyl alcohol) (PVA) matrix is demonstrated to be favorable for RTP emission, with the resulting films possessing an afterglow duration of 26 s and a lifetime of up to 2.92 s. Based on this, deep eutectic solvents (DES)‐based RTP gel is successfully prepared by cyclic freezing‐thawing and solvent exchange of aqueous solution of TPPB functionalized PVA obtained by click reaction. The obtained gel exhibited an afterglow of up to 8 s and RTP lifetime of 902 ms under ambient conditions. Further analyses showed that the introduction of DES reconstructed interactions between polymer chains damaged by water and enhanced the rigidity of the system, thus promoting RTP emission.

Frenkel defects facilitate oriented 1O2 formation in birnessite for enhanced catalytic oxidation of formaldehyde

Defect strategy is one of the most effective approaches for enhancing the efficiency of Mn-based catalysts in removing formaldehyde (HCHO) under ambient conditions. Herein, the interlayer Mn-O octahedra in birnessite synergistically form with Mn vacancies through proton exchange in acidic solutions, creating surface Frenkel defects. As evidenced by highly combined physicochemical characterization and density functional theory calculations, surface Frenkel defects are highly active sites on the surface of birnessite. The surface Frenkel defects can induce surface electronic reconstruction, generating strong electrophilicity, which promotes the evolution of superoxide radicals (O2•−) into singlet oxygen (1O2). In-situ quenching DRIFTS indicates that 1O2 is the most important ROS in the oxidation process of HCHO. Additionally, the surface Frenkel defects enhance the adsorption of HCHO, promoting the dehydrogenation of HCHO to form CO, which is then rapidly oxidized to CO2 and H2O under the action of 1O2. This provide a more effective kinetic and thermodynamic catalytic pathway. The defect-rich birnessite (R-Bir) achieved complete HCHO removal in the dynamic test at 10 ppm within 10 hours, significantly outperforming defect-free birnessite (F-Bir) and most previously reported catalysts. This study precisely reveals the catalytic mechanism of HCHO over R-Bir and provides valuable insights for the design of high-performance environmental catalysts.

Influence of boric acid on the speciation of iron (III) in aqueous solutions

During the work, the speciation of iron (III) was studied at the concentration of ~ 1∙10–5 mol/dm3 in aqueous solutions in the presence of boric acid at a concentration of 5–20 g/dm3 in a wide pH range using ion exchange, ultrafiltration and centrifugation methods. The regions of existence of ionic and nonionic forms of iron (III) were determined by ion exchange in solutions with different boric acid concentrations. Experimental data have shown that the pH of the onset of iron (III) colloid formation shifts in the presence of boric acid. The formation of complex compounds of iron (III) with polyborate ions in the neutral – slightly alkaline pH region was established by ultrafiltration and centrifugation. As shown in the paper, the increase in the concentration of boric acid in solution leads to the increase in the region of existence of the supposed complexes. The identified features of the behavior of iron (III) in solutions containing boric acid determine the possibility of using ion exchange and membrane separation methods for purifying solutions. Information about the physical-chemical properties of various metal-ions can provide optimal conditions for the purification of liquid radioactive waste at various nuclear industry facilities.

Improved longevity of actomyosin in vitro motility assays for sustainable lab-on-a-chip applications

AbstractIn the in vitro motility assay (IVMA), actin filaments are observed while propelled by surface-adsorbed myosin motor fragments such as heavy meromyosin (HMM). In addition to fundamental studies, the IVMA is the basis for a range of lab-on-a-chip applications, e.g. transport of cargoes in nanofabricated channels in nanoseparation/biosensing or the solution of combinatorial mathematical problems in network-based biocomputation. In these applications, prolonged myosin function is critical as is the potential to repeatedly exchange experimental solutions without functional deterioration. We here elucidate key factors of importance in these regards. Our findings support a hypothesis that early deterioration in the IVMA is primarily due to oxygen entrance into in vitro motility assay flow cells. In the presence of a typically used oxygen scavenger mixture (glucose oxidase, glucose, and catalase), this leads to pH reduction by a glucose oxidase-catalyzed reaction between glucose and oxygen but also contributes to functional deterioration by other mechanisms. Our studies further demonstrate challenges associated with evaporation and loss of actin filaments with time. However, over 8 h at 21–26 °C, there is no significant surface desorption or denaturation of HMM if solutions are exchanged manually every 30 min. We arrive at an optimized protocol with repeated exchange of carefully degassed assay solution of 45 mM ionic strength, at 30 min intervals. This is sufficient to maintain the high-quality function in an IVMA over 8 h at 21–26 °C, provided that fresh actin filaments are re-supplied in connection with each assay solution exchange. Finally, we demonstrate adaptation to a microfluidic platform and identify challenges that remain to be solved for real lab-on-a-chip applications.

Parallelization of Curved Inertial Microfluidic Channels to Increase the Throughput of Simultaneous Microparticle Separation and Washing

The rising global need for clean water highlights the importance of efficient sample preparation methods to separate and wash various contaminants such as microparticles. Microfluidic methods for these purposes have emerged but they mostly deliver either separation or washing, with very low throughputs. Here, we investigate parallelization of a curved-channel particle separation and washing device in order to increase its throughput for sample preparation. A curved microchannel applies inertial forces to focus larger 10 µm microparticles at the inner wall of the channel and separate them from smaller 5 µm microparticles at the outer wall. At the same time, Dean flow recirculation is used to exchange the carrier solution of the large microparticles to a clean buffer (washing). We increased the number of curved channels in a stepwise manner from two to four to eight channels in two different arraying designs, i.e., rectangular and polar arrays. We examined efficient separation of target 10 µm particles from 5 µm particles, while transferring the larger microparticles into a clean buffer. Dean flow recirculation studies demonstrated that the rectangular arrayed device performs better, providing solution exchange efficiencies of more than 96% on average as compared to 89% for the polar array device. Our 8-curve rectangular array device provided a particle separation efficiency of 98.93 ± 0.91%, while maintaining a sample purity of 92.83 ± 1.47% at a high working flow rate of 12.8 mL/min. Moreover, the target particles were transferred into a clean buffer with a solution exchange efficiency of 96.81 ± 0.54% in our 8-curve device. Compared to the literature, our in-plane parallelization design of curved microchannels resulted in a 13-fold increase in the working flow rate of the setup while maintaining a very high performance in particle separation and washing. Our microfluidic device offers the potential to enhance the throughput and the separation and washing efficiencies in applications for biological and environmental samples.

Whole-cell multi-target single-molecule super-resolution imaging in 3D with microfluidics and a single-objective tilted light sheet.

Multi-target single-molecule super-resolution fluorescence microscopy offers a powerful means of understanding the distributions and interplay between multiple subcellular structures at the nanoscale. However, single-molecule super-resolution imaging of whole mammalian cells is often hampered by high fluorescence background and slow acquisition speeds, especially when imaging multiple targets in 3D. In this work, we have mitigated these issues by developing a steerable, dithered, single-objective tilted light sheet for optical sectioning to reduce fluorescence background and a pipeline for 3D nanoprinting microfluidic systems for reflection of the light sheet into the sample. This easily adaptable novel microfluidic fabrication pipeline allows for the incorporation of reflective optics into microfluidic channels without disrupting efficient and automated solution exchange. By combining these innovations with point spread function engineering for nanoscale localization of individual molecules in 3D, deep learning for analysis of overlapping emitters, active 3D stabilization for drift correction and long-term imaging, and Exchange-PAINT for sequential multi-target imaging without chromatic offsets, we demonstrate whole-cell multi-target 3D single-molecule super-resolution imaging with improved precision and imaging speed.

Simultaneous high-throughput particle-bacteria separation and solution exchange via in-plane and out-of-plane parallelization of microfluidic centrifuges

Inertial microfluidic devices have gained attention for point-of-need (PoN) sample preparation. Yet, devices capable of simultaneous particle-bacteria solution exchange and separation are low in throughput, hindering their applicability to PoN settings. This paper introduces a microfluidic centrifuge for high-throughput solution exchange and separation of microparticles, addressing the need for processing large sample volumes at elevated flow rates. The device integrates Dean flow recirculation and inertial focusing of microparticles within 24 curved microchannels assembled in a three-layer configuration via in-plane and out-of-plane parallelization. We studied solution exchange and particle migration using singleplex and duplex samples across devices with varying curve numbers (2-curve, 8-curve, and 24-curve). Processing 5 and 10 μm microparticles at flow rates up to 16.8 ml/min achieved a solution exchange efficiency of 96.69%. In singleplex solutions, 10 and 5 μm particles selectively migrated to inner and outer outlets, demonstrating separation efficiencies of 99.7% and 90.3%, respectively. With duplex samples, sample purity was measured to be 93.4% and 98.6% for 10 and 5 μm particles collected from the inner and the outer outlets, respectively. Application of our device in biological assays was shown by performing duplex experiments where 10 μm particles were isolated from Salmonella bacterial suspension with purity of 97.8% while increasing the state-of-the-art particle solution exchange and separation throughput by 16 folds. This parallelization enabled desirable combinations of high throughput, low-cost, and scalability, without compromising efficiency and purity, paving the way for sample preparation at the PoN in the future.

Studying the Pulmonary Endothelium in Health and Disease: An Official American Thoracic Society Workshop Report.

Lung endothelium resides at the interface between the circulation and the underlying tissue, where it senses biochemical and mechanical properties of both the blood as it flows through the vascular circuit and the vessel wall. The endothelium performs the bidirectional signaling between the blood and tissue compartments that is necessary to maintain homeostasis while physically separating both, facilitating a tightly regulated exchange of water, solutes, cells, and signals. Disruption in endothelial function contributes to vascular disease, which can manifest in discrete vascular locations along the artery-to-capillary-to-vein axis. Although our understanding of mechanisms that contribute to endothelial cell injury and repair in acute and chronic vascular disease have advanced, pathophysiological mechanisms that underlie site-specific vascular disease remain incompletely understood. In an effort to improve the translatability of mechanistic studies of the endothelium, the American Thoracic Society convened a workshop to optimize rigor, reproducibility, and translation of discovery to advance our understanding of endothelial cell function in health and disease.

With No Lysine (K) Kinases and Sodium Transporter Function in Solute Exchange with Implications for BP Regulation as Elucidated through Drosophila.

Like other multicellular organisms, the fruit fly Drosophila melanogaster must maintain homeostasis of the internal milieu, including the maintenance of constant ion and water concentrations. In mammals, the with no lysine (K) (WNK)-Ste20-proline/alanine rich kinase/oxidative stress response 1 kinase cascade is an important regulator of epithelial ion transport in the kidney. This pathway regulates SLC12 family cotransporters, including sodium-potassium-2-chloride, sodium chloride, and potassium chloride cotransporters. The WNK-Ste20-proline/alanine rich kinase/oxidative stress response 1 kinase cascade also regulates epithelial ion transport via regulation of the Drosophila sodium-potassium-2-chloride cotransporter in the Malpighian tubule, the renal epithelium of the fly. Studies in Drosophila have contributed to the understanding of multiple regulators of WNK pathway signaling, including intracellular chloride and potassium, the scaffold protein Mo25, hypertonic stress, hydrostatic pressure, and macromolecular crowding. These will be discussed together, with implications for mammalian kidney function and BP control.

Deciphering simplified regional anticoagulation with citrate in intermittent hemodialysis: a clinical and computational study

Regional citrate anticoagulation use in intermittent hemodialysis is limited by the increased risk of metabolic complications due to faster solute exchanges than with continuous renal replacement therapies. Several simplifications have been proposed. The objective of this study was to validate a mathematical model of hemodialysis anticoagulated with citrate that was then used to evaluate different prescription scenarios on anticoagulant effectiveness (free calcium concentration in dialysis filter) and calcium balance. A study was conducted in hemodialyzed patients with a citrate infusion into the arterial line and a 1.25 mmol/L calcium dialysate. Calcium and citrate concentrations were measured upstream and downstream of the citrate infusion site and in the venous line. The values measured in the venous lines were compared with those predicted by the model using Bland and Altman diagrams. The model was then used with 22 patients to make simulations. The model can predict the concentration of free calcium, bound to citrate or albumin, accurately. Irrespective of the prescription scenario a decrease in free calcium below 0.4 mmol/L was obtained only in a fraction of the dialysis filter. A zero or slightly negative calcium balance was observed, and should be taken into account in case of prolonged use.

Mitochondrial permeability transition dictates mitochondrial maturation upon switch in cellular identity of hematopoietic precursors

The mitochondrial permeability transition pore (mPTP) is a supramolecular channel that regulates exchange of solutes across cristae membranes, with executive roles in mitochondrial function and cell death. The contribution of the mPTP to normal physiology remains debated, although evidence implicates the mPTP in mitochondrial inner membrane remodeling in differentiating progenitor cells. Here, we demonstrate that strict control over mPTP conductance shapes metabolic machinery as cells transit toward hematopoietic identity. Cells undergoing the endothelial-to-hematopoietic transition (EHT) tightly control chief regulatory elements of the mPTP. During EHT, maturing arterial endothelium restricts mPTP activity just prior to hematopoietic commitment. After transition in cellular identity, mPTP conductance is restored. In utero treatment with NIM811, a molecule that blocks sensitization of the mPTP to opening by Cyclophilin D (CypD), amplifies oxidative phosphorylation (OXPHOS) in hematopoietic precursors and increases hematopoiesis in the embryo. Additionally, differentiating pluripotent stem cells (PSCs) acquire greater organization of mitochondrial cristae and hematopoietic activity following knockdown of the CypD gene, Ppif. Conversely, knockdown of Opa1, a GTPase critical for proper cristae architecture, induces cristae irregularity and impairs hematopoiesis. These data elucidate a mechanism that regulates mitochondrial maturation in hematopoietic precursors and underscore a role for the mPTP in the acquisition of hematopoietic fate.

Poly (ethylene imine)-mediated dihydroxy-functionalized resin with enhanced adsorption capacity for the extraction of boron from salt lake brine

Boron selective resin is a crucial material used for extracting boron from salt lake brine, but the adsorption capacity of resin remains to be improved. In this work, a boron selective resin with high adsorption capacity was created by modifying branched poly (ethylene imine) (PEI) on chloromethyl polystyrene resin, followed by reacting with D-(+)-gluconic acid δ-lactone. The influence of surface hydroxyl content on adsorption capacity of the resin was investigated by varying molecular weights of PEI during modification. The adsorption mechanism of boric acid was explored by changing pH and composition of solution, and by analyzing the adsorption thermodynamic and kinetic behaviors. Furthermore, the selectivity of resin was assessed by the effects of coexisting ions on the adsorption rate of boric acid. The results show that PEI modification effectively increases the content of hydroxyl on the surface of the resin so as to enhance the adsorption capacity of the resin towards boric acid up to 39.4 mg/g. Also, the adsorption rate can still reach up to 75 % even in the presence of 400 times coexisting ion, showing a good selectivity. Furthermore, the adsorption of boric acid is primarily driven by boronate affinity rather than an anion exchange in alkaline solution. Finally, the dynamic extraction of boric acid was carried out, and gives an enrichment factor of up to 39.6 on fixed bed, demonstrating a potential of the resin in the field of boron extraction.