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The concept of water movement across cell membranes eventually lead to identification of water channels, known as 'Aquaporins'. The transport function exerted by aquaporins (AQPs) is carried out efficiently by 13 distinct isoforms of AQPs in mammals. AQPs help in regulation of physiological functions of various organ systems and have a functional role in stress associated with various pathological conditions. This review summarises the involvement of AQPs in transport of ROS and oxidative stress regulation in various organ systems. AQP1, AQP4, AQP7 and AQP9 are the major AQPs in the cardiac tissues of various animals, playing vital role in the patho-physiology of congestive heart failure, myocardial oedema, myocardial ischemia and polymicrobial sepsis. In digestive system, AQP1, AQP3, AQP4, AQP7, AQP8, AQP10 and AQP11 are localised in gastro-intestinal tract, modulating patho-physiology of pseudomembranous colitis, bile induced diarrhoea, irritable bowel syndrome and intestinal ulcers. AQPs in enteric tissues are engaged in metabolism of H2O2, providing a protective mechanism against oxidative stress. AQP1, AQP2, AQP3, AQP4 and AQP11 are major renal AQPs involved in ureteral obstruction, nephrogenic diabetes insipidus and kidney injury. In respiratory system, AQP1, AQP2, AQP4 and AQP5 are expressed in various pathological circumstances like lung injury and pulmonary inflammation due to oxidative stress. Thus, the evidences regarding the role of AQPs in oxidative stress offer a foundation for comprehending the adaptive mechanisms to oxidative injury at cellular level, which helps in strategizing breeding programmes and serves as biomarkers for efficient diagnosis. [ABSTRACT FROM AUTHOR]

The previously available coding region for the spiny dogfish (Squalus acanthias) AQP3-2 gene was amplified from cDNAs using PCR. Agarose gel electrophoresis gave a band of the AQP3-2 coding region, as well as multiple smaller splice variant bands. The main AQP3-2 band and the largest and most fluorescently intense pair of these splice variant bands were cloned and sequenced. Amplifications were performed on a range of tissue cDNAs, but AQP3-2 was only expressed in the kidney and brain. Quantitative PCR amplifications using pre-existing kidney cDNA from an environmental salinity acclimation experiment showed that the abundance of mRNA from both the main AQP3-2 transcript and the largest splice variant (Splice Variant 1) was lower in 120% seawater (SW) acclimated fish, although only the values for Splice Variant 1 were statistically significant. A custom-made affinity-purified rabbit polyclonal AQP3-2 antibody was produced, and this gave four bands of around the correct sizes (which were 27 and 32 kDa) for the complete AQP3-2 and Splice Variant 1 proteins. Two of the bands may have been N-glycosylated forms of these proteins. Other bands were also present on the Western blot. No bands were present when the antibody was pre-blocked by the peptide antigen. In tissue sections of the dogfish kidney, immunohistochemical localization experiments showed that AQP3-2 was expressed in the early distal tubule (EDT) and late distal tubule (LDT) nephron segments. The results suggest that AQP3-2 may be involved in cell volume regulation in the EDT and water and urea absorption in the LDT nephron segment. [ABSTRACT FROM AUTHOR]

The crustacean molting cycle is triggered by the elevation of ecdysteroid levels in the hemolymph during late pre‐molt. It is known that these animals absorb water through the intestine and gills to promote bodily swelling and rupture of the old exoskeleton. The participation of two membrane proteins responsible for the most uptake of water during the late pre‐molt has been shown in the gill and gut cells of the freshwater shrimp Palaemon argentinus: Na+/K+‐ATPase (NKA), which generates an osmoionic gradient, and Aquaporins (AQPs), water channels, which provide higher water permeability. Studies investigating the action of ecdysteroids on these proteins are scarce. Therefore, we investigated 20‐hydroxyecdisone (20E) in relation to the regulation of NKA and AQPs in the gill and gut cells of P. argentinus. We exposed primary cultures of both gut and gill cells to 20E. Gill cells treated with hormone in the presence of NKA‐blockers, exhibited a reduction in volume, and cells treated with 20E showed a greater expression of NKA than untreated cells. Additionally, gills cells treated with 20E showed an increase in volume (∼60%), which the aquaporin inhibitor (HgCl2) prevented. The participation of AQPs in the influx of water was corroborated by a greater expression of AQP in cells treated with 20E compared to untreated cells. Gut cells of animals in intermolt exposed to hormone (20E) maintained their initial cell volume. With the addition of HgCl2, these cells showed a reduction in volume similar to cells of animals in pre‐molt. Immunocytochemistry showed a high expression of AQP in gut cells treated with 20E. These findings suggest that 20E regulates the expression of AQP and NKA in the late pre‐molt, to provide water uptake for molting. This work offers new perspectives concerning the molting hormone, placing it as a crucial part of water uptake for ecdysis. [ABSTRACT FROM AUTHOR]

Intraventricular haemorrhage is a common complication of premature birth. Survivors are often left with cerebral palsy, intellectual disability and/or hydrocephalus. Animal models suggest that brain tissue shrinkage, with subsequent vascular stretch and tear, is an important step in the pathophysiology, but the cause of this shrinkage is unknown. Clinical risk factors for intraventricular haemorrhage are biomarkers of hypoxic–ischaemic stress, which causes mature neurons to swell. However, immature neuronal volume might shift in the opposite direction in these conditions. This is because immature neurons express the chloride, salt and water transporter NKCC1, which subserves regulatory volume increases in non-neural cells, whereas mature neurons express KCC2, which subserves regulatory volume decreases. When hypoxic–ischaemic conditions reduce active ion transport and increase the cytoplasmic membrane permeability, the effects of these transporters are diminished. Consequentially, mature neurons swell (cytotoxic oedema), whereas immature neurons might shrink. After hypoxic–ischaemic stress, in vivo and in vitro multi-photon imaging of perinatal transgenic mice demonstrated shrinkage of viable immature neurons, bulk tissue shrinkage and blood vessel displacement. Neuronal shrinkage was correlated with age-dependent membrane salt and water transporter expression using immunohistochemistry. Shrinkage of immature neurons was prevented by prior genetic or pharmacological inhibition of NKCC1 transport. These findings open new avenues of investigation for the detection of acute brain injury by neuroimaging, in addition to prevention of neuronal shrinkage and the ensuing intraventricular haemorrhage, in premature infants. [ABSTRACT FROM AUTHOR]

Water serves as the primary substance in all living cells and is an essential molecule involved in numerous biological processes critical for maintaining homeostasis in the central nervous system (CNS). Disruptions in water balance can occur in conditions such as cerebral edema, where fluid accumulation results in increased intracranial pressure (ICP). Aquaporins (AQPs) are transmembrane proteins that play a vital role in the rapid transport of water across cell membranes. Various subtypes of AQPs (AQP1, AQP3, AQP4, AQP5, AQP6, AQP7, AQP8, AQP9, and AQP11) have been identified in brain tissue. This review summarizes the latest advancements in our understanding of the critical role of AQPs in regulating water transport in brain edema. Abundant evidence indicates that AQP4, the most prevalent AQP in the CNS, regulates brain water transport and contributes to both cytotoxic and vasogenic edema, suggesting that AQP4 may serve as a potential therapeutic target for brain edema. Additionally, some studies have indicated that AQP1 plays a significant role in the formation of cerebrospinal fluid (CSF) and the maintenance of steady-state ICP. However, to date, these findings have not been translated into clinical practice. There is an urgent need to develop specific AQP inhibitors and activators to explore the potential benefits of modulating the functions of AQP1 and AQP4 in the context of brain edema.

The biophysics of water, has been debated over more than a century. Although its importance is still underestimated, significant breakthroughs occurred in recent years. The influence of protein condensation on water availability control was documented, new findings on water-transport proteins emerged, and the way water molecules rearrange to minimize free energy at interfaces was deciphered, influencing membrane thermodynamics. The state of knowledge continued to progress in the field of deep-sea marine biology, highlighting unknown effects of high hydrostatic pressure and/or temperature on interactions between proteins and ligands in extreme environments, and membrane structure adaptations. The role of osmolytes in protein stability control under stress is also discussed here in relation to fish egg hydration/buoyancy. The complexity of water movements within the cell is updated, all these findings leading to a better view of their impact on many cellular processes. The way water flow and osmotic gradients generated by ion transport work together to produce the driving force behind cell migration is also relevant to both marine biology and cancer research. Additional common points concern water dynamic changes during the neoplastic transformation of cells and tissues, or embryo development. This could improve imaging techniques, early cancer diagnosis, and understanding of the molecular and physiological basis of buoyancy for many marine species. [ABSTRACT FROM AUTHOR]

The biophysics of water, has been debated over more than a century. Although its importance is still underestimated, significant breakthroughs occurred in recent years. The influence of protein condensation on water availability control was documented, new findings on water-transport proteins emerged, and the way water molecules rearrange to minimize free energy at interfaces was deciphered, influencing membrane thermodynamics. The state of knowledge continued to progress in the field of deep-sea marine biology, highlighting unknown effects of high hydrostatic pressure and/or temperature on interactions between proteins and ligands in extreme environments, and membrane structure adaptations. The role of osmolytes in protein stability control under stress is also discussed here in relation to fish egg hydration/buoyancy. The complexity of water movements within the cell is updated, all these findings leading to a better view of their impact on many cellular processes. The way water flow and osmotic gradients generated by ion transport work together to produce the driving force behind cell migration is also relevant to both marine biology and cancer research. Additional common points concern water dynamic changes during the neoplastic transformation of cells and tissues, or embryo development. This could improve imaging techniques, early cancer diagnosis, and understanding of the molecular and physiological basis of buoyancy for many marine species.

Aquaporins (AQPs) allow the diffusion of hydrogen peroxide (H2O2) and act as ROS scavenging systems, which are important for controlling the redox state of cells. Recently, cerium oxide nanoparticles were found to increase the water and H2O2 permeability by modulating AQPs. To further analyze the action of nanoparticles (NPs) on AQP, we examined the effect of the NPs presenting different core compositions (CeO2, Gd2O3, Fe3O4, and TiO2), hydrodynamic sizes, and surface functionalization. The NPs produced an increase in H2O and H2O2 permeability as a general trend. The hydrodynamic sizes of the NPs in the range of 22–100 nm did not produce any significant effect. The chemical nature of the NPs' core did not modify the effect and its intensity. On the other hand, the NPs' functionalized surface plays a major role in influencing both water and H2O2 permeability. The results suggest that NPs can play a significant role in controlling oxidative stress in cells and might represent an innovative approach in the treatment of a number of pathologies associated with an increased oxidative status. [ABSTRACT FROM AUTHOR]

This study aims to assess and analyze the water quality of water channels in Al-Harthah district, southern Iraq, using eight key physical and chemical indicators. These indicators include ambient air temperature, water temperature, electrical conductivity, water transparency, pH, dissolved oxygen, total dissolved solids, and oxidation-reduction potential. Measurements were conducted at 124 sampling stations during both winter and summer of the year 2022. Aquameter and Seechi disk were used for measurements. The study found an increase in electrical conductivity, total dissolved solids, and oxidation-reduction potential values, along with a decrease in dissolved oxygen quantity and water transparency. These values tend to increase in summer compared to winter, indicating that the water quality in the study area tends towards salinity, turbidity, and oxidizing environment. The study also indicated some statistical correlations among the studied variables. [ABSTRACT FROM AUTHOR]

المدن المائية مصطلح يطلق على التجمعات العمرانية المتداخلة مع المسطحات المائية، أشهرها مدينتي البندقية بإيطاليا وامستردام بهولندا التي تتسم بالقنوات المائية والكباري. ويوجد مدن حديثة مثل جزيرة النخلة الصناعية بدبي، والمنتجعات السياحية بالمالديف المشتهرة بالبناء على دعامات فوق الماء. وتنتشر في مصر التجمعات المائية مثل بعض قري الصيادين في البحيرات الشمالية ومنطقة المكس بالإسكندرية ومدينة الجونة بالغردقة. ويساعد دمج القنوات والمساحات المائية في المدن علي زيادة النشاط الاقتصادي والسياحة والنقل بتكلفة وتلوث أقل، وتوفر إطلالات جمالية وراحة حرارية، ويمكن ان تساعد على مواجهة مخاطرارتفاع مستوي سطح البحر.وبالرغم من انتشار المدن المائية وتعدد فوائدها وأنواعها، مازال لا يوجد تعريف أو تصنيف متفق عليه، فنجد المصطلح يطلق على أي تجمع متداخل مع الماء، بالرغم من وجود اختلاف في السمات والخصائص بين تجمعاتها. وهنا يأتي دور البحث في تحديد وتصنيف الأنماط الرئيسية للمدن المائية، واستنتاج خصائص وسمات كل نوع، لكي يساهم في فهم المدن المائية القائمة وتطويرها والحفاظ عليها أو تخطيط وتصميم مدن مائية جديدة على أساس علمي واضح. ولقد قام البحث من خلال منهج وصفي تحليلي تحديد هيكل عام لتصنيف أنواع المدن المائية من خلال تحليل مقارن لخمسة وثلاثين حالة دراسية حول العالم. ولقد تم تطبيق هذا الهيكل على الحالات الدراسية من خلال منهج تطبيقي تحليلي لتحديد للأنماط الرئيسية للمدن المائية. وخلص البحث الي أن التصنيف الرئيسي لأنماط المدن المائية هو الذي ينبني على طرق التخطيط والتشكيل العمراني للمدينة وهي (مدن القنوات، مدن الجزر الاصطناعية، المدن العائمة، مدن القوائم). كما تم استنتاج السمات الرئيسية لكل لنوع من خلال دراسة مقارنة بين الأنماط الرئيسية للمدن المائية والهيكل العام للتصنيف. Water cities are urban communities that overlap water bodies, most notably cities such as Venice in Italy and Amsterdam in the Netherlands, which are characterized by aqueducts and bridges. There are modern cities, such as Dubai's Palm Jumeirah Artificial Island, as well as tourist attractions in the Maldives famous for their pillars built on water. Water communities are widely distributed in Egypt, such as some fishermen's villages in the northern lakes, Al Max area in Alexandria, and the city of El Gouna in Hurghada. The integration of aqueducts and water bodies in cities helps increase economic activity, tourism and transportation at lower cost and pollution. It provides scenic views and thermal comfort and helps address the risks of rising sea levels. Despite the wide distribution of water cities and their variety of strengths and types, no agreed definition or classification has yet been reached. The term refers to any community overlapped with water, although there were differences in features and characteristics between its communities. The research identifies and classifies the main types of water cities, and deduces the features and characteristics of each type, in order to help understand, develop and protect the existing water cities or plan and design new water cities on a clear scientific basis. Using a descriptive and analytical approach, the research identifies a general structure of water city typology through a comparative analysis of thirty-five case studies around the world. It is done by applying the analytical methods to identify the main types of water cities. The research concluded that the main classification of water city models is mainly based on urban planning and urban formation methods, namely (canal city, artificial island city, floating city, stilt city). The main characteristics of each type are deduced through the comparative study of the main types of water cities and the overall structure of the classification.

Ice condition monitoring (ICM) is critical for the operation and maintenance of water supply infrastructure in cold regions. Existing approaches either depend on ground-level sensors or satellite photography for ICM, which suffer from high maintenance costs or inadequate precision. Computer vision (CV) has the potential to tackle the limitations by providing a precise and scalable solution based on near-shore cameras and increasingly affordable drones. To explore the potential of CV for ICM, this paper presents a systematic study of salient image features for differentiating typical ice evolvement phases throughout the freeze–thaw cycle. First, ice condition during the freeze–thaw cycle is studied to provide a categoric system of typical ice stages. Second, multiple image feature descriptors are proposed to characterize the distinction between different ice conditions. Finally, with the proposed descriptors as input, two support vector machines (SVMs) are trained to classify the ice condition for automatic ICM. Experiments have been implemented to identify salient features for ice characterization. It was found that the SVMs can achieve 71.9 and 77.3% accuracy for the prediction of ice stage and ice flow strength, respectively. Future research is suggested to develop the research findings into practical solutions for webcams or drone-based automatic ICM. HIGHLIGHTS Computer vision is used to monitor ice conditions in water supply infrastructure.; Image features are handcrafted to characterize different ice conditions.; Effectiveness of the features is quantified and evaluated by correlation analysis.;

Despite of the major role of aquaporin (AQP) water channels in controlling transmembrane water fluxes, alternative ways for modulating water permeation have been proposed. In the Central Nervous System (CNS), Aquaporin-4 (AQP4) is reported to be functionally coupled with the calcium-channel Transient-Receptor Potential Vanilloid member-4 (TRPV4), which is controversially involved in cell volume regulation mechanisms and water transport dynamics. The present work aims to investigate the selective role of TRPV4 in regulating plasma membrane water permeability in an AQP4-independent way. Fluorescence-quenching water transport experiments in Aqp4-/- astrocytes revealed that cell swelling rate is significantly increased upon TRPV4 activation and in the absence of AQP4. The biophysical properties of TRPV4-dependent water transport were therefore assessed using the HEK-293 cell model. Calcein quenching experiments showed that chemical and thermal activation of TRPV4 overexpressed in HEK-293 cells leads to faster swelling kinetics. Stopped-flow light scattering water transport assay was used to measure the osmotic permeability coefficient (Pf, cm/s) and activation energy (Ea, kcal/mol) conferred by TRPV4. Results provided evidence that although the Pf measured upon TRPV4 activation is lower than the one obtained in AQP4-overexpressing cells (Pf of AQP4 = 0.01667 ± 0.0007; Pf of TRPV4 = 0.002261 ± 0.0004; Pf of TRPV4 C 4aPDD = 0.007985 ± 0.0006; Pf of WT = 0.002249 ± 0.0002), along with activation energy values (Ea of AQP4 = 0.86 ± 0.0006; Ea of TRPV4 C 4aPDD = 2.73 ± 1.9; Ea of WT = 8.532 ± 0.4), these parameters were compatible with a facilitated pathway for water movement rather than simple diffusion. The possibility to tune plasma membrane water permeability more finely through TRPV4 might represent a protective mechanism in cells constantly facing severe osmotic challenges to avoid the potential deleterious effects of the rapid cell swelling occurring via AQP channels. [ABSTRACT FROM AUTHOR]

Introduction: Aquaporins (AQPs) are constituted by a water‑channel protein family that is distributed among different tissues. Its expression has been shown to have a significant correlation with the aggressiveness of tumors as well as prognosis. Aim: The current narrative review aimed to highlight the role of AQPs in maintaining homeostasis in cellular functioning and their expressions in diseased states and other conditions. Methods: A search was performed after entering Boolean operators with words such as “AQPs” AND “Oral health.” Research papers or systematic reviews which were published in PubMed indexed or those with Medline citations and within the past 10 years were included in the study. Results: A total of forty articles were selected during the initial screening of search engines, of which 37 articles were included in the review, while three papers were excluded, of which 1 was nonpeer reviewed and two papers did not fulfill selected inclusion criteria. Discussion: AQPs are important intramembranous transportation channels that play a significant role in both physiological and pathological conditions of the orofacial complex. The present review provides an overview of the pathophysiology involving AQPs that can help scientists to design treatment therapeutics for various disease conditions. [ABSTRACT FROM AUTHOR]

Despite of the major role of aquaporin (AQP) water channels in controlling transmembrane water fluxes, alternative ways for modulating water permeation have been proposed. In the Central Nervous System (CNS), Aquaporin-4 (AQP4) is reported to be functionally coupled with the calcium-channel Transient-Receptor Potential Vanilloid member-4 (TRPV4), which is controversially involved in cell volume regulation mechanisms and water transport dynamics. The present work aims to investigate the selective role of TRPV4 in regulating plasma membrane water permeability in an AQP4-independent way. Fluorescence-quenching water transport experiments in Aqp4–/– astrocytes revealed that cell swelling rate is significantly increased upon TRPV4 activation and in the absence of AQP4. The biophysical properties of TRPV4-dependent water transport were therefore assessed using the HEK-293 cell model. Calcein quenching experiments showed that chemical and thermal activation of TRPV4 overexpressed in HEK-293 cells leads to faster swelling kinetics. Stopped-flow light scattering water transport assay was used to measure the osmotic permeability coefficient (Pf, cm/s) and activation energy (Ea, kcal/mol) conferred by TRPV4. Results provided evidence that although the Pf measured upon TRPV4 activation is lower than the one obtained in AQP4-overexpressing cells (Pf of AQP4 = 0.01667 ± 0.0007; Pf of TRPV4 = 0.002261 ± 0.0004; Pf of TRPV4 + 4αPDD = 0.007985 ± 0.0006; Pf of WT = 0.002249 ± 0.0002), along with activation energy values (Ea of AQP4 = 0.86 ± 0.0006; Ea of TRPV4 + 4αPDD = 2.73 ± 1.9; Ea of WT = 8.532 ± 0.4), these parameters were compatible with a facilitated pathway for water movement rather than simple diffusion. The possibility to tune plasma membrane water permeability more finely through TRPV4 might represent a protective mechanism in cells constantly facing severe osmotic challenges to avoid the potential deleterious effects of the rapid cell swelling occurring via AQP channels.

The altered expression of known brain Aquaporin (AQP) channels 1, 4 and 9 has been correlated with neuropathological AD progression, but possible roles of other AQP classes in neurological disease remain understudied. The levels of transcripts of all thirteen human AQP subtypes were compared in healthy and Alzheimer's disease (AD) brains by statistical analyses of microarray RNAseq expression data from the Allen Brain Atlas database. Previously unreported, AQPs 0, 6 and 10, are present in human brains at the transcript level. Three AD-affected brain regions, hippocampus (HIP), parietal cortex (PCx) and temporal cortex (TCx), were assessed in three subgroups: young controls (n = 6, aged 24–57); aged controls (n = 26, aged 78–99); and an AD cohort (n = 12, aged 79–99). A significant positive correlation (p < 10−10) was seen for AQP transcript levels as a function of the subject's age in years. Differential expressions correlated with brain region, age, and AD diagnosis, particularly between the HIP and cortical regions. Interestingly, three classes of AQPs (0, 6 and 8) upregulated in AD compared to young controls are permeable to H2O2. Of these, AQPs 0 and 8 were increased in TCx and AQP6 in HIP, suggesting a role of AQPs in AD-related oxidative stress. The outcomes here are the first to demonstrate that the expression profile of AQP channels in the human brain is more diverse than previously thought, and transcript levels are influenced by both age and AD status. Associations between reactive oxygen stress and neurodegenerative disease risk highlight AQPs 0, 6, 8 and 10 as potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO)-based membranes have been widely studied for realizing efficient wastewater treatment, due to their easily functionalizeable surfaces and tunable interlayer structures. However, the irregular structure of water channels within GO-based membrane has largely confined water permeance and prevented the simultaneously improvement of purification performance. Herein, we purposely construct the well-structured three-dimensional (3D) water channels featuring regular and negatively-charged properties in the GO/SiO2 composite membrane via in situ close-packing assembly of SiO2 nanoparticles onto GO nanosheets. Such regular 3D channels can improve the water permeance to a record-high value of 33,431.5 ± 559.9 L·m−2·h−1 (LMH) bar−1, which is several-fold higher than those of current state-of-the-art GO-based membranes. We further demonstrate that benefiting from negative charges on both GO and SiO2, these negatively-charged 3D channels enable the charge selectivity well toward dye in wastewater where the rejection for positive-charged and negative-charged dye molecules is 99.6% vs. 7.2%, respectively. The 3D channels can also accelerate oil/water (O/W) separation process, in which the O/W permeance and oil rejection can reach 19,589.2 ± 1,189.7 LMH bar−1 and 98.2%, respectively. The present work unveils the positive role of well-structured 3D channels on synchronizing the remarkable improvement of both water permeance and purification performance for highly efficient wastewater treatment. [ABSTRACT FROM AUTHOR]

Some aquaporins (AQPs) allow the diffusion of hydrogen peroxide (H2O2), the most abundant ROS, through the cell membranes. Therefore, the possibility of regulating the AQP-mediated permeability to H2O2, and thus ROS scavenging, appears particularly important for controlling the redox state of cells in physiological and pathophysiological conditions. Several compounds have been screened and characterized for this purpose. This study aimed to analyze the effect of cerium oxide nanoparticles (CNPs) presenting antioxidant activity on AQP functioning. HeLa cells express AQP3, 6, 8, and 11, able to facilitate H2O2. AQP3, 6, and 8 are expressed in the plasma membrane and intracellularly, while AQP11 resides only in intracellular structures. CNPs but not cerium ions treatment significantly increased the water and H2O2 permeability by interacting with AQP3, 6, and especially with AQP8. CNPs increased considerably the AQP-mediated water diffusion in cells with oxidative stress. Functional experiments with silenced HeLa cells revealed that CNPs increased the H2O2 diffusion mainly by modulating the AQP8 permeability but also the AQP3 and AQP6, even if to a lesser extent. Current findings suggest that CNPs represent a promising pharmaceutical agent that might potentially be used in numerous pathologies involving oxidative stress as tumors and neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Forward osmosis (FO) membranes have the advantages of low energy consumption, high water recovery rate, and low membrane pollution trend, and they have been widely studied in many fields. However, the internal concentration polarization (ICP) caused by the accumulation of solutes in the porous support layer will reduce permeation efficiency, which is currently unavoidable. In this paper, we doped Graphene oxide (GO) nanoparticles (50~150 nm) to a polyamide (PA) active layer and/or polysulfone (PSF) support layer, investigating the influence of GO on the morphology and properties of thin-film composite forward osmosis (TFC-FO) membranes. The results show that under the optimal doping amount, doping GO to the PA active layer and PSF support layer, respectively, is conducive to the formation of dense and uniform nano-scale water channels perpendicular to the membrane surface possessing a high salt rejection rate and low reverse solute flux without sacrificing high water flux. Moreover, the water channels formed by doping GO to the active layer possess preferable properties, which significantly improves the salt rejection and water permeability of the membrane, with a salt rejection rate higher than 99% and a water flux of 54.85 L·m−2·h−1 while the pure PSF-PA membrane water flux is 12.94 L·m−2·h−1. GO-doping modification is promising for improving the performance and structure of TFC-FO membranes. [ABSTRACT FROM AUTHOR]

We studied cell recruitment following optic tectum (OT) injury in zebrafish (Danio rerio), which has a remarkable ability to regenerate many of its organs, including the brain. The OT is the largest dorsal layered structure in the zebrafish brain. In juveniles, it is an ideal structure for imaging and dissection. We investigated the recruited cells within the juvenile OT during regeneration in a Pdgfrβ-Gal4:UAS-EGFP line in which pericytes, vascular, circulating, and meningeal cells are labeled, together with neurons and progenitors. We first performed high-resolution confocal microscopy and single-cell RNA-sequencing (scRNAseq) on EGFP-positive cells. We then tested three types of injury with very different outcomes (needle (mean depth in the OT of 200 µm); deep-laser (depth: 100 to 200 µm depth); surface-laser (depth: 0 to 100 µm)). Laser had the additional advantage of better mimicking of ischemic cerebral accidents. No massive recruitment of EGFP-positive cells was observed following laser injury deep in the OT. This type of injury does not perturb the meninx/brain–blood barrier (BBB). We also performed laser injuries at the surface of the OT, which in contrast create a breach in the meninges. Surprisingly, one day after such injury, we observed the migration to the injury site of various EGFP-positive cell types at the surface of the OT. The migrating cells included midline roof cells, which activated the PI3K-AKT pathway; fibroblast-like cells expressing numerous collagen genes and most prominently in 3D imaging; and a large number of arachnoid cells that probably migrate to the injury site through the activation of cilia motility genes, most likely being direct targets of the FOXJ1a gene. This study, combining high-content imaging and scRNAseq in physiological and pathological conditions, sheds light on meninges repair mechanisms in zebrafish that probably also operate in mammalian meninges. [ABSTRACT FROM AUTHOR]

The traditional irrigation systems in the Upper Indus Basin (UIB) are frequently disrupted by climate-induced hazards, affecting irrigated agriculture – one of the major livelihood sources in the region. The recent scholarship lacks systematic data on various aspects that make the mountain irrigation systems susceptible to climate variabilities. Therefore, we investigated the climate vulnerability of irrigations systems at selected sites of the UIB, using a tailored 'multidimensional indices' approach. The sites represented a cross-section of socio-hydrological and physiographic attributes. The data on multiple dimensions of vulnerability and corresponding indicators were acquired through household surveys, using a semi-structured questionnaire. The findings revealed a 'medium-high' level of vulnerability of irrigation systems, which is a great concern, given the fragility of the mountainous ecosystems. Overall, the level of vulnerably didn't vary across the sites, presumably due to physiographic and socio-cultural similarities, however, the various dimensions of vulnerability differed across the sites. The study concludes that appropriate adaptation measures are necessary to reduce the vulnerability of irrigation systems, especially by enhancing institutional resilience. This can be achieved by building capacities of local institutions and enhancing government's financial, technical, and policy support for local communities in maintaining the traditional irrigation systems under the changing climatic conditions. [ABSTRACT FROM AUTHOR]

Achiral 2‐hydroxy‐N‐(diphenylmethyl)acetamide (HNDPA) crystallizes in the P61 chiral space group as a hydrate, building up permeable chiral crystalline helical water channels. The crystallization‐driven chiral self‐resolution process is highly robust, with the same air‐stable crystalline form readily obtained under a variety of conditions. Interestingly, the HNDPA supramolecular helix inner pore is filled by a helical water wire. The whole edifice is mainly stabilized by robust hydrogen bonds involving the HNDPA amide bonds and CH...π interactions between the HNDPA phenyl groups. The crystalline structure shows breathing behavior, with completely reversible release and re‐uptake of water inside the chiral channel under ambient conditions. Importantly, the HNDPA channel is able to transport water very efficiently and selectively under biomimetic conditions. With a permeability per channel of 3.3 million water molecules per second in large unilamellar vesicles (LUV) and total selectivity against NaCl, the HNDPA channel is a very promising functional nanomaterial for future applications. [ABSTRACT FROM AUTHOR]

The physiological variations during the crustacean molting cycle have intrigued researchers for many years. Maintaining osmotic homeostasis in the face of hemolymph dilution and dealing with dynamic intracellular and extracellular calcium fluctuations are challenges these animals continuously confront. It has recently been shown that water channels present in the cell membrane (aquaporins) are essential for water uptake during premolt and postmolt. This study aims to investigate whether hypoosmotic shock and intracellular and extracellular calcium variations can lead to translocation of Aquaporin 1 (AQP‐1) from the intracellular region to the plasma membrane during premolt and postmolt, thus allowing increased water flow in these stages. For this, we investigate in vitro the rapid change of AQP‐1 positions in the abdominal muscle cells in the freshwater shrimp, Palaemon argentinus. Using cell volume analysis and immunohistochemistry, we show that hypoosmotic conditions and an elevation of the intracellular and extracellular calcium concentrations are concurrent with the translocation of AQP‐1 to the plasma membrane. These results indicate that calcium flux and hypoosmotic shock may be regulators of AQP 1 in the translocation process. [ABSTRACT FROM AUTHOR]

G-protein-coupled receptors (GPCRs) are involved in a wide range of physiological processes, and they have attracted considerable attention as important targets for developing new medicines. A central and largely unresolved question in drug discovery, which is especially relevant to GPCRs, concerns ligand selectivity: Why do certain molecules act as activators (agonists) whereas others, with nearly identical structures, act as blockers (antagonists) of GPCRs? To address this question, we employed all-atom, long-timescale molecular dynamics simulations to investigate how two diastereomers (epimers) of dihydrofuroaporphine bind to the serotonin 5-HT1A receptor and exert opposite effects. By using molecular interaction fingerprints, we discovered that the agonist could mobilize nearby amino acid residues to act as molecular switches for the formation of a continuous water channel. In contrast, the antagonist epimer remained firmly stabilized in the binding pocket.

Progressing climate change necessitates the search for solutions of plant protection against the effects of water deficit. One of these solutions could be silicon supplementation. The aim of the study was to verify the hypothesis that silicon changes aquaporin expression and antioxidant system activity in a direction which may alleviate the effects of drought stress in oilseed rape. The accumulation of BnPIP1, BnPIP2-1-7 and BnTIP1;1 aquaporins and the expression of their genes, the level of catalase, superoxide dismutase activities and hydrogen peroxide content as well as total non-enzymatic antioxidant activity were analyzed in leaf tissue from control and silicon-treated oilseed rape plants growing under well-watered and drought conditions. Silicon was applied in two forms – pure silicon and a silicon complex. It was shown that under drought conditions, both pure silicon and the silicon complex (with Fe) significantly increased the accumulation of aquaporins and improved the activity of enzymatic and non-enzymatic components of the antioxidant system, while under well-watered conditions, these effects were observed only in the case of the silicon complex. The presented study proves that silicon supplementation in oilseed rape improves the regulation of water management and contributes to the protection against oxidative stress caused by drought. • Silicon supplementation in oilseed rape alleviates the effects of drought stress. • Silicon improves the activity of antioxidative enzymes in drought. • Silicon increases the accumulation of PIP and TIP aquaporins in oilseed rape. [ABSTRACT FROM AUTHOR]

The altered expression of known brain Aquaporin (AQP) channels 1, 4 and 9 has been correlated with neuropathological AD progression, but possible roles of other AQP classes in neurological disease remain understudied. The levels of transcripts of all thirteen human AQP subtypes were compared in healthy and Alzheimer’s disease (AD) brains by statistical analyses of microarray RNAseq expression data from the Allen Brain Atlas database. Previously unreported, AQPs 0, 6 and 10, are present in human brains at the transcript level. Three AD-affected brain regions, hippocampus (HIP), parietal cortex (PCx) and temporal cortex (TCx), were assessed in three subgroups: young controls (n = 6, aged 24–57); aged controls (n = 26, aged 78–99); and an AD cohort (n = 12, aged 79–99). A significant positive correlation (p < 10−10) was seen for AQP transcript levels as a function of the subject’s age in years. Differential expressions correlated with brain region, age, and AD diagnosis, particularly between the HIP and cortical regions. Interestingly, three classes of AQPs (0, 6 and 8) upregulated in AD compared to young controls are permeable to H2O2. Of these, AQPs 0 and 8 were increased in TCx and AQP6 in HIP, suggesting a role of AQPs in AD-related oxidative stress. The outcomes here are the first to demonstrate that the expression profile of AQP channels in the human brain is more diverse than previously thought, and transcript levels are influenced by both age and AD status. Associations between reactive oxygen stress and neurodegenerative disease risk highlight AQPs 0, 6, 8 and 10 as potential therapeutic targets.

Plant PIP aquaporins play a central role in controlling plant water status. The current structural model for PIP pH‐gating states that the main pH sensor is located in loopD and that all the mobile cytosolic elements participate in a complex interaction network that ensures the closed structure. However, the precise participation of the last part of the C‐terminal domain (CT) in PIP pH gating remains unknown. This last part has not been resolved in PIP crystal structures and is a key difference between PIP1 and PIP2 paralogues. Here, by a combined experimental and computational approach, we provide data about the role of CT in pH gating of Beta vulgaris PIP. We demonstrate that the length of CT and the positive charge located among its last residues modulate the pH at which the open/closed transition occurs. We also postulate a molecular‐based mechanism for the differential pH sensing in PIP homo‐ or heterotetramers by performing atomistic molecular dynamics simulations (MDS) on complete models of PIP tetramers. Our findings show that the last part of CT can affect the environment of loopD pH sensors in the closed state. Results presented herein contribute to the understanding of how the characteristics of CT in PIP channels play a crucial role in determining the pH at which water transport through these channels is blocked, highlighting the relevance of the differentially conserved very last residues in PIP1 and PIP2 paralogues. [ABSTRACT FROM AUTHOR]

Throughout the history, water served and sustained societies, and it was considered one of the crucial factors for their development. People have shaped their flow, form, and function for the development of settlements and civilizations and have created socio-economic and cultural structures around them. Looking at the historical development of the city of Prizren, the city has been spread and developed around the river, which passes in the middle of it. The clean and flowing water from the river was one of the most important factors in the development of the city. The city of Prizren was also known for its sophisticated system of water channels used to have that played a very important role in the urban area. The water channels were branched from the river and scattered throughout the neighborhoods of the city. Further, these channels branched into smaller channels, which carried water through small public streets to each house in Prizren. The paper deals with the revitalization method to restore these historical water channels in the Historic Center of Prizren to modern requirements, from which the greatest benefit would have the citizens of Prizren in social, economic, spatial, and environmental aspects. [ABSTRACT FROM AUTHOR]

Aquaporins (AQPs), as transmembrane proteins, were primarily identified as water channels with the ability of regulating the transmission of water, glycerol, urea, and other small‐sized molecules. The classic view of AQPs involvement in therapeutic plan restricted them and their regulators into managing only a narrow spectrum of the diseases such as diabetes insipidus and the syndrome of inappropriate ADH secretion. However, further investigations performed, especially in the third millennium, has found that their cooperation in water transmission control can be manipulated to handle other burden‐imposing diseases such as cirrhosis, heart failure, Meniere's disease, cancer, bullous pemphigoid, eczema, and Sjögren's syndrome. [ABSTRACT FROM AUTHOR]

High-scored premium wines are typically produced under moderate drought stress, suggesting that the water status of grapevine is crucial for wine quality. Aquaporins greatly influence the plant water status by facilitating water diffusion across the plasma membrane in a tightly regulated manner. They adjust the hydraulic conductance of the plasma membrane rapidly and reversibly, which is essential in specific physiological events, including adaptation to soil water scarcity. The comprehension of the sophisticated plant-water relations at the molecular level are thus important to optimize agricultural practices or to assist plant breeding programs. This review explores the recent progresses in understanding the water transport in grapevine at the cellular level through aquaporins and its regulation. Important aspects, including aquaporin structure, diversity, cellular localization, transport properties, and regulation at the cellular and whole plant level are addressed. An ecophysiological perspective about the roles of grapevine aquaporins in plant response to drought stress is also provided. [ABSTRACT FROM AUTHOR]

The Evaporative Cooling Technology has revived in the past few decades owing to the gradual shift of economies towards investing in sustainable cooling systems which has led to many governments defining sustainability targets in reducing GHG emissions and achieving climate neutrality with many EU countries aiming to reach net zero emissions by 2050. The major contribution towards GHGs are the conventional air conditioning systems which incorporate energy intensive compressor units and refrigerants as working fluids. A great deal of research has been done on the Evaporative Cooling Technology particularly, the DEC – Direct Evaporative Cooling systems due to their cost-effectiveness, design simplicity and feasibility. The present study proposes a HIDEC – Hybrid Indirect Direct Evaporative Cooling System as an alternative to the conventional vapor compression systems which is unique considering its compact and two in one design incorporating both Indirect and Direct Cooling Channels in a single system. The HIDEC Experimental System is developed passing through the stages of fabrication and design, followed by realtime testing in the hot and humid, and hot and dry sub tropical climatic conditions of Islamabad. The HIDEC Experimental System when operated in Dual Hybrid Mode provides a substantial supply air temperature drop to 24.8 °C with a maximum achievable COP of 35.2 and Cooling Capacity of 16.8 kW. The overall wet bulb effectiveness of the system elevates to 85%, whereas the dew point effectiveness reaches a maximum of 80%. [ABSTRACT FROM AUTHOR]

Background: Mesenchymal stem cells (MSC) improve renal function and renovascular hypertension in the 2-kidney 1-clip model (2K-1C). While MSC play an immunomodulatory role, induce neoangiogenesis, and reduce fibrosis, they do not correct sodium loss by the contra­lateral kidney. Objectives: We investigated the tubular function of both stenotic and contralateral kidneys and the effect of MSC treatment by evaluating diuresis, natriuresis, and the expression of the main water and sodium transporters. Method: Adult Wistar rats were allocated into four groups: control (CT), CT+MSC, 2K-1C, and 2K-1C+MSC. MSC (2 × 105) were infused through the tail vein 3 and 5 weeks after clipping. Systolic blood pressure (SBP) was monitored weekly by plethysmography. Six weeks after clipping, 24-hour urine and blood samples were collected for biochemical analysis. Gene expression of the Na/H exchanger-3, epithelial sodium channel, Na/K-ATPase, Na/K/2Cl cotransporter, and aquaporins 1 and 2 (AQP1 and AQP2) were analyzed by RT-PCR. Intrarenal distribution of AQP1 and AQP2 was analyzed by immunohistochemistry. Results: In hypertensive 2K-1C animals, MSC prevented additional increases in BP. AQP1, but not AQP2, was suppressed in the contralateral kidney, resulting in significant increase in urinary flow rate and sodium excretion. Gene expressions of sodium transporters were similar in both kidneys, suggesting that the high perfusing pressure in the contralateral kidney was responsible for increased natriuresis. Contralateral hypertensive kidney showed signs of renal deterioration with lower GFR in spite of normal RPF levels. Conclusions: MSC treatment improved renal function and enhanced the ability of the contralateral kidney to excrete sodium through a tubular independent mechanism contributing to reduce SBP.

Male infertility is one of the many problems currently faced by science and medicine. Despite intensive research in this area conducted in recent years, the reasons for the lack of the desired pregnancy are often unrecognized. The current standards and general recommendations, including the World Health Organization (WHO) guidelines for diagnostic testing of male reproductive organs and sperm quality analysis, seem to be insufficient. Hence, it has been postulated for years that it is necessary to search for and identify new, unknown factors that significantly affect male fertility, and to define modern indicators/biomarkers that would enable precise determination of male reproductive potential. Among the many interesting recently published data, the information on the identification and expression analysis of aquaporins (AQPs) in the male reproductive system and metabolomic semen analysis is of particular interest. In this review, we will try to solve the question whether AQPs and metabolomic sperm analysis can be the answer to the current needs and whether their measurements may become a useful parameter in the future for determining male reproductive potential. [ABSTRACT FROM AUTHOR]

Ion and water channels were recently shown to be involved in cancer cell functions, and various transporter types have been detected in upper gastrointestinal tract (UGI) cancers. Current information on the expression and roles of these channels and transporters in the death and survival of UGI cancer cells was reviewed herein, and the potential of their regulation for cancer management was investigated. Esophageal cancer (EC) and gastric cancer (GC) cells and tissues express many different types of ion channels, including voltage-gated K+, Cl–, and Ca2+, and transient receptor potential (TRP) channels, which regulate the progression of cancer. Aquaporin (AQP) 1, 3, and 5 are water channels that contribute to the progression of esophageal squamous cell carcinoma (ESCC) and GC. Intracellular pH regulators, including the anion exchanger (AE), sodium hydrogen exchanger (NHE), and vacuolar H+-ATPases (V-ATPase), also play roles in the functions of UGI cancer cells. We have previously conducted gene expression profiling and revealed that the regulatory mechanisms underlying apoptosis in ESCC cells involved various types of Cl– channels, Ca2+ channels, water channels, and pH regulators (Shimizu et al., 2014; Ariyoshi et al., 2017; Shiozaki et al., 2017, 2018a; Kobayashi et al., 2018; Yamazato et al., 2018; Konishi et al., 2019; Kudou et al., 2019; Katsurahara et al., 2020, 2021; Matsumoto et al., 2021; Mitsuda et al., 2021). We have also previously demonstrated the clinicopathological and prognostic significance of their expression in ESCC patients, and shown that their pharmacological blockage and gene silencing had an impact on carcinogenesis, indicating their potential as targets for the treatment of UGI cancers. A more detailed understanding of the molecular regulatory mechanisms underlying cell death and survival of UGI cancers may result in the application of cellular physiological methods as novel therapeutic approaches.

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Flexible zinc-air batteries are the leading candidates as the next-generation power source for flexible/wearable electronics. However, constructing safe and high-performance solid-state electrolytes (SSEs) with intrinsic hydroxide ion (OH - ) conduction remains a fundamental challenge. Herein, by adopting the natural and robust cellulose nanofibers (CNFs) as building blocks, the biomass SSEs with penetrating ion and water channels are constructed by knitting the OH - -conductive CNFs and water-retentive CNFs together via an energy-efficient tape casting. Benefiting from the abundant ion and water channels with interconnected hydrated OH - wires for fast OH - conduction under a nanoconfined environment, the biomass SSEs reveal the high water-uptake, impressive OH - conductivity of 175 mS cm -1 and mechanical robustness simultaneously, which overcomes the commonly existed dilemma between ion conductivity and mechanical property. Remarkably, the flexible zinc-air batteries assemble with biomass SSEs deliver an exceptional cycle lifespan of 310 h and power density of 126 mW cm -2 . The design methodology for water and ion channels opens a new avenue to design high-performance SSEs for batteries., (© 2024 Wiley‐VCH GmbH.)

The movement of water across the cell membrane is a natural biological process that occurs during growth, cell division, and cell death. Many cells are known to regulate changes in their cell volume through inherent compensatory regulatory mechanisms. Cells can sense an increase or decrease in their cell volume, and compensate through mechanisms known as a regulatory volume increase (RVI) or decrease (RVD) response, respectively. The transport of sodium, potassium along with other ions and osmolytes allows the movement of water in and out of the cell. These compensatory volume regulatory mechanisms maintain a cell at near constant volume. A hallmark of the physiological cell death process known as apoptosis is the loss of cell volume or cell shrinkage. This loss of cell volume is in stark contrast to what occurs during the accidental cell death process known as necrosis. During necrosis, cells swell or gain water, eventually resulting in cell lysis. Thus, whether a cell gains or loses water after injury is a defining feature of the specific mode of cell death. Cell shrinkage or the loss of cell volume during apoptosis has been termed apoptotic volume decrease or AVD. Over the years, this distinguishing feature of apoptosis has been largely ignored and thought to be a passive occurrence or simply a consequence of the cell death process. However, studies on AVD have defined an underlying movement of ions that result in not only the loss of cell volume, but also the activation and execution of the apoptotic process. This review explores the role ions play in controlling not only the movement of water, but the regulation of apoptosis. We will focus on what is known about specific ion channels and transporters identified to be involved in AVD, and how the movement of ions and water change the intracellular environment leading to stages of cell shrinkage and associated apoptotic characteristics. Finally, we will discuss these concepts as they apply to different cell types such as neurons, cardiomyocytes, and corneal epithelial cells.

Self-assembling peptides can be used to design new materials for medical and biological applications. Here we synthesized and characterized two novel cyclic γ-peptides (γ-CPs) with hydrophobic inner surfaces. The NMR and FT-IR studies confirmed that the CPs could self-assemble into parallel stacking structures via intermolecular H-bonds and π-π interactions. The morphologies of the self-assembly CPs showed bundles of nanotubes via transmission electron microscopy (TEM); these nanotubes form water channels to transport water across the lipid membrane. The properties of blocking the transport of protons like natural water channels showed that the hydrophobic inner surfaces are important in artificial transmembrane water channel designs. These studies also showed that water transport was a function of pore size and length of the assemblies.

Natural Aquaporin (AQP) channels are efficient water translocating proteins, rejecting ions. Inspired by this masterpiece of nature, Artificial Water Channels (AWCs) with controlled functional structures, can be potentially used to mimic the AQPs to a certain extent, offering flexible avenues toward biomimetic membranes for water purification. The objective of this paper is to trace the historical development and significant advancements of current reported AWCs. Meanwhile, we attempt to reveal important structural insights and supramolecular self‐assembly principles governing the selective water transport mechanisms, toward innovative AWC‐based biomimetic membranes for desalination. [ABSTRACT FROM AUTHOR]

Due to the merit of very‐short end turns, Gramme‐ring windings are widely used in high‐speed permanent‐magnet motors (HSPMMs). This study investigated the thermal issues of a 300 kW, 12,000 rpm Gramme‐ring‐winding HPSMM with housing water jacket and forced air cooling, based on the computational fluid dynamics (CFD) and numerical heat‐transfer calculations. The reasons that cause the overheat of the prototype in the experimental test are thoroughly analysed. The high wind resistance of air gap as the ventilation duct and the large interface gap between the stator lamination and housing water jacket is thought to be the main reasons. Then improvement of the ventilation structures is studied to decrease the wind resistance. Besides, the modification of water channels is also investigated to avoid the influence of a large interface gap on the water cooling performance. Finally, a new cooling structure, combining the slot ventilation ducts and inside water channels, is proposed for the HSPMM with Gramme‐ring windings. With the new cooling structure, the temperature rise of the motor is decreased, and the power density can be increased. [ABSTRACT FROM AUTHOR]

A minireview of pharmacological strategies used to ameliorate polyuria associated with X-linked nephrogenic diabetes insipidus. Am J Physiol Renal Physiol 319: F746-F753, 2020. First published September 14, 2020; doi:10.1152/ajprenal.00339.2020.-- Nephrogenic diabetes insipidus (NDI) is characterized by renal resistance to the antidiuretic hormone arginine vasopressin (AVP), which leads to polyuria, plasma hyperosmolarity, polydipsia, and impaired quality of living. Inherited forms are caused by X-linked loss-of-function mutations in the gene encoding the vasopressin 2 receptor (V2R) or autosomal recessive/dominant mutations in the gene encoding aquaporin 2 (AQP2). A common acquired form is lithiuminduced NDI. AVP facilitates reabsorption of water through increased abundance and insertion of AQP2 in the apical membrane of principal cells in the collecting ducts. In X-linked NDI, V2R is dysfunctional, which leads to impaired water reabsorption. These patients have functional AQP2, and thus the challenge is to achieve AQP2 membrane insertion independently of V2R. The current treatment is symptomatic and is based on distally acting diuretics (thiazide or amiloride) and cyclooxygenase inhibitors (indomethacin). This mini-review covers published data from trials in preclinical in vivo models and a few human intervention studies to improve NDI by more causal approaches. Promising effects on NDI in preclinical studies have been demonstrated by the use of pharmacological approaches with secretin, Wnt5a, protein kinase A agonist, fluconazole, prostaglandin E2 EP2 and EP4 agonists, statins, metformin, and soluble prorenin receptor agonists. In patients, only casuistic reports have evaluated the effect of statins, phosphodiesterase inhibitors (rolipram and sildenafil), and the guanylate cyclase stimulator riociguat without amelioration of symptoms. It is concluded that there is currently no established intervention that causally improves symptoms or quality of life in patients with NDI. There is a need to collaborate to improve study quality and conduct formal trials. [ABSTRACT FROM AUTHOR]

[Display omitted] • DMSNs with unique dendritic structures exhibited superior dispersibility. • Well-dispersed DMSNs helped reduce potential defects in the PA selective layer. • The central-radial pore structure of DMSNs acted as interior water channels in the membrane. • TFN-DMSNs achieved high permselectivity of up to 32.25 bar−1 for water/Na 2 SO 4. • TFN-DMSNs possessed high acid/alkali resistance and anti-fouling performance. Improving the dispersibility of nanomaterials is a promising approach to enhance the performance of thin-film nanocomposite (TFN) membranes. In this study, hydrophilic nonporous, mesoporous, and dendritic mesoporous silica nanoparticles (NSNs, MSNs, and DMSNs) with a uniform particle size were utilized as aqueous phase additives to prepare TFN membranes through in-situ polymerization. The electrostatic adsorption of nanoparticles increased the concentration of amine monomers on the surface of the polysulfone (PSF) substrate. In collaboration with the steric hindrance effect, nanoparticles restricted the diffusion of piperazine (PIP) into the organic phase to polymerize with the acyl chloride monomers. Compared to TFC-0, the TFN membranes exhibited a rougher surface with increased negative charge and had more channels that facilitated the transportation of water molecules. Among the nanoparticles, DMSNs exhibited excellent dispersibility, ensuring their uniform distribution within the polyamide (PA) matrix. Furthermore, DMSNs possessed an open central-radial pore structure, offering more efficient channels for water molecules to cross the membrane. Therefore, a highly crosslinked, defect-free, and hydrophilic PA layer of TFN-DMSNs was achieved. In the performance characterization, TFN-DMSNs demonstrated a high water/salt permselectivity (A/B) of up to 32.25 bar−1, and exhibited good resistance to acidic/alkaline environments as well as foulants during the operation. This study proposes a novel approach to prepare advanced TFN membranes by optimizing the morphological structure of nanoparticles. [ABSTRACT FROM AUTHOR]

The interaction between cells and the extracellular medium is of great importance, and drastic changes in extracellular solute concentrations drive water movement across the plasma membrane. Aquaporins (AQPs) are a family of transmembrane channels that allow the transport of water and small solutes across cell membranes. Different members of this family have been identified in gametes. In sperm, they are relevant to osmoadaptation after entering the female reproductive tract, which is crucial for sperm motility activation and capacitation and, thus, for their fertilizing ability. In addition, they are relevant during the cryopreservation process, since some members of this family are also permeable to glycerol, one of the most frequently used cryoprotective agents in livestock. Regarding oocytes, AQPs are very important in their maturation but also during cryopreservation. Further research to define the exact sets of AQPs that are present in oocytes from different species is needed, since the available literature envisages certain AQPs and their roles but does not provide complete information on the whole set of AQPs. This is of considerable importance because, in sperm, specific AQPs are known to compensate the role of non-functional members.

In this paper, we propose a hemispherical reconfigurable frequency selective surface (FSS) using water channels. The switching between band-pass and band-stop states is possible since the water with a high dielectric constant can control the effective permittivity of the structure. We simulate and fabricate the FSS and measure the radiation pattern of FSS enclosed horn antenna to check the reconfigurable characteristic of the hemispherical FSS. The simulated results show a good agreement with the measured results.

Demand for kidney grafts outpaces supply, limiting kidney transplantation as a treatment for kidney failure. Xenotransplantation has the potential to make kidney transplantation available to many more patients with kidney failure, but the ability of xenografts to support human physiologic homeostasis has not been established. A brain-dead adult decedent underwent bilateral native nephrectomies followed by 10 gene-edited (four gene knockouts, six human transgenes) pig-to-human xenotransplantation. Physiologic parameters and laboratory values were measured for seven days in a critical care setting. Data collection aimed to assess homeostasis by measuring components of the renin-angiotensin-aldosterone system, parathyroid hormone signaling, glomerular filtration rate, and markers of salt and water balance. Mean arterial blood pressure was maintained above 60 mmHg throughout. Pig kidneys secreted renin (post-operative day three to seven mean and standard deviation: 47.3 ± 9 pg/mL). Aldosterone and angiotensin II levels were present (post-operative day three to seven, 57.0 ± 8 pg/mL and 5.4 ± 4.3 pg/mL, respectively) despite plasma renin activity under 0.6 ng/mL/hr. Parathyroid hormone levels followed ionized calcium. Urine output down trended from 37 L to 6 L per day with 4.5 L of electrolyte free water loss on post-operative day six. Aquaporin 2 channels were detected in the apical surface of principal cells, supporting pig kidney response to human vasopressin. Serum creatinine down trended to 0.9 mg/dL by day seven. Glomerular filtration rate ranged 90-240 mL/min by creatinine clearance and single-dose inulin clearance. Thus, in a human decedent model, xenotransplantation of 10 gene-edited pig kidneys provided physiologic balance for seven days. Hence, our in-human study paves the way for future clinical study of pig-to-human kidney xenotransplantation in living persons., (Copyright © 2024 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)