Background Forward osmosis (FO) membranes are promising for water treatment because of their low energy consumption, high rejection, and low fouling tendency, but their performance is limited by internal concentration polarization (ICP), reverse salt flux, and fouling. Developing thin and porous support layers is critical for alleviating ICP and enhancing water permeability. This study aims to investigate whether incorporating COFs-TATP into the PES support layer can alleviate internal concentration polarization while simultaneously improving water flux and suppressing reverse salt flux. Methods In this study, β-ketoenamine-linked COFs-TATP nanomaterials with abundant functional groups were synthesized through condensation of 1,3,5-triformylphloroglucinol (TFP) and 1,3,5-tris(4-aminophenyl)benzene (TAPB), and then incorporated into a polyethersulfone (PES) support layer. A polyamide (PA) selective layer was subsequently formed by interfacial polymerization of m-phenylenediamine (MPD) and trimesoyl chloride (TMC), yielding a high-performance PA/COFs@PES FO membrane. Significant findings The incorporation of COFs-TATP improved the hydrophilicity and porosity of the PES support layer, which was accompanied by enhanced water transport, reduced reverse salt diffusion, improved antifouling behavior, and favorable operational stability. Under optimized conditions with 0.1 wt% COFs-TATP and 2 M NaCl draw solution, the membrane achieved a water flux of 46.84 LMH and reverse salt flux of 5.51 GMH, representing a 44.5% increase and 26.5% decrease, respectively, compared with pristine PA/PES membranes. These findings suggest that support-layer engineering through the incorporation of hydrophilic porous COFs-TATP may represent a feasible strategy for simultaneously enhancing water transport and suppressing reverse salt transport in thin-film composite FO membranes, which may be useful for the future development of FO membranes for seawater desalination.
A graph G is said to be perfectly divisible if for every induced subgraph H of G with at least one edge, the vertex set V(H) can be partitioned into two sets A, B such that H[A] is perfect and ω(B) < ω(H). It is easy to see that the chromatic number of a perfectly divisible graph is at most ω(G)+12. Hoàng conjectured that every graph G with α(G) ≤ 3 is perfectly divisible. We disprove this conjecture. In the same vein, a graph G with at least one edge is k-divisible if for every induced subgraph H of G with at least one edge, the vertex set V(H) can be partitioned into k sets, none of which contains a largest clique of H. It is easy to see that the chromatic number of a k-divisible graph is at most k^ω-1. Hoàng conjectured that every even-hole-free graph is 3-divisible. We confirm this conjecture.
This study analysed the impact of mobile service quality in fitness clubs on customer satisfaction and loyalty, identifying key service quality items that require improvement. This study adopts a questionnaire survey method, collecting data on mobile service quality, customer satisfaction, and loyalty from members of fitness clubs in Fujian, China. A total of 381 valid questionnaires were collected. Data analysis was conducted using Statistical Package for the Social Sciences (SPSS), linear structural relations (LISREL) statistical software, and importance-performance and gap analysis (IPGA). Statistical analysis indicates that mobile service quality positively impacts customer satisfaction and loyalty. Customer satisfaction acts as a mediator between mobile service quality and customer loyalty, facilitating the indirect effect of service quality on loyalty. Using IPGA, we identified five key quality items of fitness clubs' mobile service that require improvement.
Vibrio parahaemolyticus, a globally distributed bacterium in estuarine and coastal waters, poses a significant threat to seafood safety. The spread of antimicrobial resistance (AMR) in V. parahaemolyticus transcends phylogenetic, geographic, and ecological boundaries, raising concerns about its impact on marine ecosystems. This study investigated the prevalence and AMR profiles of V. parahaemolyticus in seafood in retail markets in Zhangzhou City, China. A total of 288 aquatic samples were collected aseptically from July 2023 to June 2024. Sixty-one V. parahaemolyticus isolates were identified using standard methods (cultural, biochemical, PCR) and characterized for virulence genes, AMR genes, antibiotic susceptibility, and molecular type. Multi-drug resistance (MDR) was then analyzed. The overall isolation rate of V. parahaemolyticus was 21% (61/288). A significant proportion of isolates exhibited high resistance to minocycline (97%), penicillin (93%), and cefazolin (90%). Lower resistance rates were observed for piperacillin (3%), ceftriaxone (5%), ceftazidime (7%), and cefoperazone (7%). Multi-antimicrobial resistance (MAR) indices revealed that 54% of isolates were resistant to more than ten antimicrobials. ERIC-PCR and RAPD typing grouped the isolates into four clusters each, with the majority (86.89% and 88.13%, respectively) belonging to Group I, indicating a high degree of genetic similarity among many isolates. The high prevalence of MDR V. parahaemolyticus in retail seafood suggests excessive antimicrobial use in aquaculture practices within this region. Effective antimicrobial stewardship programs, coupled with comprehensive surveillance, are urgently needed to mitigate the development and spread of AMR in V. parahaemolyticus and safeguard both human health and the health of marine ecosystems from pollution linked to aquaculture practices.
Previous studies have found that the pathology of post-stroke aphasia might be related to abnormalities in the white matter connectivity. However, it is still unclear about the neural mechanism of white matter impairment in the post-stroke aphasia. The present study attempted to detect the alteration of the brain white matter structural network in the post-stroke aphasia. We recruited 16 PSA patients who suffered from post-stroke aphasia and 14 healthy controls and acquired their diffusion-tensor imaging data. We performed a deterministic white matter fiber tracking to construct white matter structural network and estimated network topological properties by using graph theory. We also assessed the between-group differences in these parameters and estimated the correlations between the abnormal parameters and clinical assessments in the patients. The patients showed higher shortest path length, higher normalized clustering coefficient, and lower global efficiency than the controls. We found abnormal nodal parameters in the frontal, parietal, basal ganglia, and limbic regions in the patient group. From the rich-club analysis, we found that the patient group showed higher rich-club connections and lower feeder connections than the control group, and had a new rich-club region, the right fusiform gyrus. In summary, this study detected the abnormal both nodal and global parameters of the brain white matter structural network in the post-stroke aphasia. These findings may provide insights into understanding the abnormal brain network and impairment of language function in the post-stroke aphasia.
