Search

Growing demand for water desalination promoted the vigorous development of reverse osmosis (RO) membrane. How to effectively remove boron from seawater is the key problem to be solved by RO membrane. It is important to select suitable membrane materials for experimental design before complicated and expensive experimental attempts. In this paper, we demonstrate that pore chemistry plays a key role in boron removal capability of RO membranes via nonequilibrium molecular dynamics simulations. This study shows that the introduction of hydroxyl (-OH) groups into the Covalent organic frameworks (COFs) pore allows for better boron removal without changing water permeability. The optimal boron rejection of AB-COF membranes is 76.67%, and that of ATFG-COF membranes with hydroxyl groups can achieve 90%. This is caused by the hydrophilic pore of ATFG-COF that will preferentially adsorb water molecules to prevent the passage of boric acid molecules through membrane zone. Additionally, -OH groups on the pore will also adsorb a part of boric acid in the membranes, reducing the amount of boric acid entering into the permeate side. The results obtained in this paper can provide guidance for the rational design of RO membranes to achieve more efficient boron removal.

1. Introduction Exposure to microgravity during spaceflight has been shown to induce physiological adaptations of the heart and vessels, leading to the occurrence of postflight cardiovascular deconditioning, including orthostatic intolerance [...], Functional and structural adaptation of common carotid artery could be one of the important causes of postflight orthostatic intolerance after microgravity exposure, the mechanisms of which remain unclear. Recent evidence indicates that long- term spaceflight increases carotid artery stiffness, which might present a high risk to astronaut health and postflight working ability. Studies have suggested that vascular calcification is a common pathological change in cardiovascular diseases that is mainly manifested as an increase in vascular stiffness. Therefore, this study investigated whether simulated microgravity induces calcification of common carotid artery and to elucidate the underlying mechanisms. Four-week-old hindlimb-unweighted (HU) rats were used to simulate the deconditioning effects of microgravity on cardiovascular system. We found that simulated microgravity induced vascular smooth muscle cell (VSMC) osteogenic differentiation and medial calcification, increased receptor activator of nuclear factor [kappa]B (NF-[kappa]B) ligand (RANKL) and RANK expression, and enhanced NF-[kappa]B activation in rat common carotid artery. In vitro activation of the RANK pathway with exogenous RANKL, a RANK ligand, increased RANK and osteoprotegerin (OPG) expression in HU rats. Moreover, the expression of osteogenic markers and activation of NF-[kappa]B in HU rats were further enhanced by exogenous RANKL but suppressed by the RANK inhibitor osteoprotegerin fusion protein (OPG-Fc). These results indicated that the OPG/RANKL/RANK system modulates VSMC osteogenic differentiation and medial calcification of common carotid artery in simulated microgravity rats by regulating the NF- [kappa]B pathway. Key words: simulated microgravity, common carotid artery, vascular calcification, receptor activator of nuclear factor [kappa]B, osteoprotegerin. L&apos;adaptation fonctionnelle et structurelle de l&apos;artere carotide commune pourrait l&apos;une des causes importantes d&apos;intolerance orthostatique apres envol a la suite d&apos;une exposition a la microgravite, mais les modes d&apos;action demeurent a clarifier. Des donnees probantes recentes montrent que le voyage spatial de longue duree entraine une augmentation de la rigidite des arteres carotides, ce qui pourrait exposer l&apos;astronaute a un risque accru pour sa sante de meme que pour sa capacite fonctionnelle apres un envol. Des etudes ont laisse entrevoir que les calcifications vasculaires constituent une observation pathologique frequente dans les maladies cardiovasculaires, lesquelles se manifestent surtout par une augmentation de la rigidite vasculaire. Par consequent, cette etude portait sur la possibilite que la microgravite entraine une calcification de l&apos;artere carotide, ainsi que sur les modes d&apos;action sous-jacents. A l&apos;aide du soulagement de la charge portee par les pattes posterieures chez le rat (rats HU pour << hindlimb-unweighted >>) pendant quatre semaines, nous avons simule les effets de deconditionnement du systeme cardiovasculaire par la microgravite. Nous avons observe que la simulation de la microgravite entrainait une differenciation osteogenique des cellules musculaires lisses vasculaires (CMLV) et une calcification de la media, une augmentation de l&apos;expression du ligand du facteur nucleaire (FN) [kappa]B (ou RANKL pour << receptor activator of nuclear factor [kappa]B >>) et de RANK, avec une augmentation de l&apos;activation du FN- [kappa]B dans l&apos;artere carotide commune chez le rat. L&apos;activation in vitro de la voie de signalisation de RANK avec du RANKL exogene, un ligand de RANK, entrainait une augmentation de l&apos;expression de RANK et de l&apos;osteoprotegerine (OPG) chez les rats HU. En outre, l&apos;expression de marqueurs de l&apos;osteogenese et&apos;activation du FN-[kappa]B chez les rats HU augmentait encore davantage avec l&apos;administration de RANKL exogene, mais etait inhibee avec l&apos;OPG-Fc, un inhibiteur de RANK. Ces resultats montraient que le systeme OPG/RANKL/RANK participe a la modulation de la differentiation osteogenique des CMLV et a la calcification de la media de l&apos;artere carotide commune avec la microgravite simulee chez le rat, et ce, par l&apos;intermediaire de la regulation de la voie de signalisation du FN-[kappa]B. [Traduit par la Redaction] Mots-cles : microgravite simulee, artere carotide commune, calcification vasculaire, activateur des recepteurs du facteur nucleaire [kappa]B, osteoprotegerine.

The development of numerous diseases, such as renal cyst, cancer, and viral infection, is closely associated with the pathological changes and defects in the cellular peripheral brush. Therefore, it is necessary to develop a potential new method to detect lesions of cellular peripheral brush. Here, a piecewise linear viscoelastic constitutive model of cell is established considering the joint contribution of the peripheral brush and intra-cellular structure. By combining the Laplace transformation and its inverse transformation, and the differential method in the temporal domain and differential quadrature method (DQM) in the spatial domain, the signal interpretation models for quasi-static and dynamic signals of microcantilever are solved. The influence mechanisms of the peripheral brush on the viscoelastic properties of cells and quasi-static/dynamic signals of microcantilever are clarified. The results not only reveal that the peripheral brush has significant effects on the complex modulus of the cell and multi-channel signals of the microcantilever, but also suggest that an alternative mapping method by collecting multi-channel signals including quasi-static and higher frequency signals with more brush indexes could be potentially used to identify cancerous cells. [ABSTRACT FROM AUTHOR]

Euphorbia pekinensis (EP) is a commonly used Chinese medicine treating edema with potential hepatorenal toxicity. However, its toxic mechanism and prevention are remained to be explored. Oleanolic acid (OA) is a triterpene acid with potential hepatorenal protective activities. We investigated the protective effect and potential mechanism of OA on EP‐induced hepatorenal toxicity. In this study, rats were given total diterpenes from EP (TDEP, 16 mg/kg) combined with OA (10, 20, 40 mg/kg) by gavage for 4 weeks. The results showed that TDEP administration could lead to a 3–4‐fold increasement in hepatorenal biochemical parameters with histopathological injuries, while OA treatment could ameliorate them in a dose‐dependent manner. At microbial and metabolic levels, intestinal flora and host metabolism were perturbed after TDEP administration. The disturbance of bile acid metabolism was the most significant metabolic pathway, with secondary bile acids increasing while conjugated bile acids decreased. OA treatment can improve the disorder of intestinal flora and metabolic bile acid spectrum. Further correlation analysis screened out that Escherichia‐Shigella, Phascolarctobacterium, Acetatifactor, and Akkermansia were closely related to the bile acid metabolic disorder. In conclusion, oleanolic acid could prevent hepatorenal toxicity induced by EP by regulating bile acids metabolic disorder via intestinal flora improvement. [ABSTRACT FROM AUTHOR]