In silico study of structure and water dynamics in CNT/polyamide nanocomposite reverse osmosis membranes.

CNT-based reverse osmosis membranes have long been regarded as one of the most promising candidates for water desalination. However, it is a pity that there is no complete understanding of the exact role of CNTs in those nanocomposite membranes. To address this issue, three atomistic models of PA (pure polyamide membrane), PA-CNT1 (polyamide nanocomposite membrane with an embedded carbon nanotube oriented vertical to the membrane surface) and PA-CNT2 (polyamide nanocomposite with an embedded carbon nanotube oriented parallel to the membrane surface) were constructed respectively in this work. Then, equilibrium molecular dynamics (EMD) and non-equilibrium molecular dynamics (NEMD) simulations were conducted to investigate the structure and water dynamics in these three models. The EMD simulations revealed a better stacking of the PA matrix due to the addition of the CNT and this impact was more significant in PA-CNT1 than in PA-CNT2. Meanwhile, PA matrix near the mouth of the CNT was found to behave as an obstruction that hindered the exchange of water molecules inside and outside the CNT. In NEMD simulations, we found that water molecules were guided away from the CNT because of the better stacked surrounding PA matrix. The partially covered CNT might not help to increase water flux in PA-CNT1 while guided water molecules and the smaller polymer region afftected by the CNT contributed to a relatively high flux in PA-CNT2. The current work might serve as a comprehensive understanding of the role of CNTs in the reverse osmosis process.

Elucidating the substance basis and pharmacological mechanism of Fufang Qiling granules in modulating xanthine oxidase for intervention in hyperuricemia.

ETHNOPHARMACOLOGICAL RELEVANCE: Fufang Qiling granules (FQG), derived from the traditional Qiling Decoction with a longstanding clinical history, is utilized for the treatment of hyperuricemia (HUA). FQG is formulated with a combination of seven Chinese herbs based on the principles of traditional Chinese medicine (TCM) theories. Clinical evidence indicates that FQG exhibits favorable therapeutic effects in reducing uric acid (UA) levels and attenuating renal damage. AIM OF THIS STUDY: To elucidate the potential active components and pharmacological mechanism of FQG in the treatment of HUA, and to provide an experimental basis for the development of efficient and low-toxicity TCM for HUA treatment. MATERIALS AND METHODS: A HUA rat model induced by potassium oxonate and adenine was established to initially evaluate the hypouricemic effects of FQG. Chemical analyses were conducted using an ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Network pharmacology was used to investigate the active components and mechanism of FQG in the treatment of HUA. Potential Xanthine oxidase (XOD) inhibitors were screened from FQG based on ultrafiltration liquid chromatography and mass spectrometry (UF-LC-MS). Molecular docking, surface plasmon resonance (SPR) and circular dichroism (CD) spectroscopy were applied to validate the interactions between the active components and XOD. RESULTS: In comparison to the model group, treatment with FQG significantly decreased serum UA, serum creatinine (CREA), serum blood urea nitrogen (BUN), and liver XOD activity. Additionally, the FQG administration notably ameliorated HUA-induced renal injury in rats. Through the pharmacodynamics of the HUA rat models and network pharmacology, it was found that XOD was a key pathway enzyme in UA metabolism. 18 XOD inhibitors were screened from FQG by UF-LC-MS, and 11 compounds with strong affinity were verified by SPR, molecular docking and CD spectroscopy. CONCLUSION: In summary, flavonoids, organic acids and saponins may be the active components in FQG that alleviate HUA. The primary mechanism of FQG involves inhibiting XOD enzyme activity in the plasma to reduce UA production, alleviating renal tubular epithelial cell necrosis, tubulointerstitial injury, fibrosis, and urate deposition, ultimately exerting a therapeutic effect on HUA.

Discovery of drug targets based on traditional Chinese medicine microspheres (TCM-MPs) fishing strategy combined with bio-layer interferometry (BLI) technology.

Target discovery of natural products is a key step in the development of new drugs, and it is also a difficult speed-limiting step. In this study, a traditional Chinese medicine microspheres (TCM-MPs) target fishing strategy was developed to discover the key drug targets from complex system. The microspheres are composed of Fe3O4 magnetic nanolayer, oleic acid modified layer, the photoaffinity group (4- [3-(Trifluoromethyl)-3H-diazirin-3-yl] benzoic acid, TAD) layer and active small molecule layer from inside to outside. TAD produces highly reactive carbene under ultraviolet light, which can realize the self-assembly and fixation of drug active small molecules with non-selective properties. Here, taking Shenqi Jiangtang Granules (SJG) as an example, the constructed TCM-MPs was used to fish the related proteins of human glomerular mesangial cells (HMCs) lysate. 28 differential proteins were screened. According to the target analysis based on bioinformatics, GNAS was selected as the key target, which participated in insulin secretion and cAMP signaling pathway. To further verify the interaction effect of GNAS and small molecules, a reverse fishing technique was established based on bio-layer interferometry (BLI) coupled with UHPLC-Q/TOF-MS/MS. The results displayed that 26 small molecules may potentially interact with GNAS, and 7 of them were found to have strong binding activity. In vitro experiments for HMCs have shown that 7 active compounds can significantly activate the cAMP pathway by binding to GNAS. The developed TCM-MPs target fishing strategy combined with BLI reverse fishing technology to screen out key proteins that directly interact with active ingredients from complex target protein systems is significant for the discovery of drug targets for complex systems of TCM.

Coordinated single-molecule micelles: a self-template approach for preparing mesoporous doped carbons.

Porous carbons prepared using a self-template approach inherit the pore features of template, but they exhibit almost no evenly dispersed mesopores, which is significant for diffusion-limited applications. Herein, N-doped hierarchically porous carbons (NHPCs) with uniform mesopores are prepared using a self-template method. The spherical single-molecule micelle of polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP) is turned into a Zn2+-coordinated PS-b-P4VP micelle (CPM) by coordination of Zn2+ with the P4VP shell. Then, the self-template of the CPM is carbonized into a hollow carbon nanosphere. During carbonization, the PS core is decomposed to generate the central mesopore, whereas the Zn2+-coordinated P4VP shell is transformed into a carbonaceous shell. These even hollow carbon nanospheres aggregate to form uniformly mesoporous carbon lumps. Simultaneously, the coordinated Zn2+ of the CPM is reduced to metal zinc at high temperatures and then it is evaporated, thus creating numerous micropores in the carbonaceous shell. These NHPCs with uniform mesopores display a high specific surface area. As a demonstration in diffusion-limited applications, their catalytic performances for the oxygen reduction reaction (ORR) are investigated. Strikingly, NHPCs exhibit outstanding catalytic performances for the ORR. This self-template method paves a facile approach for preparing mesoporous carbons with high performances.

Iron Nanoclusters as Template/Activator for the Synthesis of Nitrogen Doped Porous Carbon and Its CO2 Adsorption Application.

We propose a facile synthesis approach for nitrogen doped porous carbon and demonstrate a novel pore-forming method that iron nanoclusters act as a template or activator at different carbonization temperatures based on Fe3+-poly(4-vinyipyridine) (P4VP) coordination. P4VP will completely decompose even in an inert atmosphere, but under the coordination and catalysis of Fe3+, it can be converted to carbon at a very low temperature (400 °C). The aggregation of iron nanoclusters in the carbonization process showed different pore-forming methods at different temperatures. The as-prepared materials possess high specific surface area (up to 1211 m2 g-1), large pore volume (up to 0.96 cm3 g-1), narrow microporosity, and high N content (up to 9.9 wt %). Due to these unique features, the materials show high CO2 uptake capacity and excellent selectivity for CO2/N2 separation. The CO2 uptake capacity of NDPC-2-600 is up to 6.8 and 4.3 mmol g-1 at 0 and 25 °C; the CO2/N2 (0.15/0.85) selectivity at 0 and 25 °C also reaches 18.4 and 15.2, respectively.

High performance proton exchange membranes obtained by adjusting the distribution and content of sulfonic acid side groups.

The proton conductivity and oxidation resistance as well as dimensional stability of hydrocarbon proton exchange membranes were simultaneously improved, achieving exciting overall properties.

Sulfonated poly(arylene ether sulfone)s with phosphine oxide moieties: a promising material for proton exchange membranes.

Sulfonated poly(arylene ether sulfone)s with phosphine oxide moieties (sPESPO) were achieved by polycondensation of bis(4-hydroxyphenyl)phenylphosphine oxide with 3,3'-disulfonate-4,4'-difluorodiphenyl sulfone (SFDPS) and 4-fluorophenyl sulfone (FPSF). Sulfonated poly(arylene ether sulfone)s (sPES) were also synthesized by polymerization of 4,4'-sulfonyldiphenol with SFDPS and FPSF for comparison. The comparative study demonstrates that the sPESPO ionomers exhibit strong intermolecular interactions and high oxidative stability because of the phosphine oxide groups. Furthermore, the sPESPO membrane and the sPES membrane with an equal ion exchange capacity show much different nanophase separation morphology. As a result, the former shows better properties than the latter. The sPESPO membranes exhibit excellent overall properties. For instance, the sPESPO membrane, with a disulfonation degree of 45%, exhibits high thermal and oxidative stability. Moreover, it shows a water uptake of 30.8% and a swelling ratio of 15.8% as well as a proton conductivity of 0.087 S/cm at 80 degrees C.