Degradation of Polyamide Nanofiltration Membranes by Bromine: Changes of Physiochemical Properties and Filtration Performance.

The potential coexistence and interaction of bromine and polyamide membranes during membrane-based water treatment prompts us to investigate the effect of bromine on membrane performance. For fully aromatic polyamide membrane NF90 exposed under a mild bromination condition (10 mg/L), bromine incorporation resulted in more negatively charged (-13 vs -25 mV) and hydrophobic (55.2 vs 58.9°) surfaces and narrower pore channels (0.3 vs 0.29 nm). The permeabilities of water and neutral solutes were reduced by 64 and 69-87%, respectively, which was attributed to the decreased effective pore radius and hydrophilicity. NaCl permeability was reduced by 90% as a synergistic result of enhanced size exclusion and charge repulsion. The further exposure (100 and 500 mg/L bromine) resulted in a more hydrophobic surface (61.7 and 65.5°) and the minor further reduction for water and solute permeabilities (1-9%). Compared with chlorine, the different incorporation efficiency and properties (e.g., atomic size, hydrophilicity) of bromine resulted in opposite trends and/or different degrees for the variation of physicochemical properties and filtration performance of membranes. The bromine incorporation, the shift and disappearance of three characteristic bands, and the increased O/N ratio and calcium content indicated the degradation pathways of N-bromination and bromination-promoted hydrolysis under mild bromination conditions (480 mg/L·h). The further ring-bromination occurred after severe bromine exposure (4800-24,000 mg/L·h). The semi-aromatic polyamide membrane NF270 underwent a similar but less significant deteriorated filtration performance compared with NF90, which requires a different explanation.

Medical services for sports injuries and illnesses in the Beijing 2022 Olympic Winter Games.

BACKGROUND: Beijing 2022 Olympic Winter Games was the second Games held amid the COVID-19 pandemic. To a certain extent, it has altered the way sporting activities operate. There is a lack of knowledge on injury risk and illness occurrence in elite winter sport athletes amid the COVID-19 pandemic. This study aimed to describe the incidence of injuries and illnesses sustained during the XXIV Olympic Winter Games in Beijing from February 4 to 20, 2022. METHODS: We recorded the daily number of injuries and illnesses among athletes reported by Beijing 2022 medical staff in the polyclinic, medical venues, and ambulance. We calculated injury and illness incidence as the number of injuries or illnesses occurring during competition or training, respectively, with incidence presented as injuries/illnesses per 100 athlete-days. RESULTS: In total, 2,897 athletes from 91 nations experienced injury or illness. Beijing 2022 medical staff reported 326 injuries and 80 illnesses, equaling 11.3 injuries and 2.8 illnesses per 100 athletes over the 17-day period. Altogether, 11% of the athletes incurred at least one injury and nearly 3% incurred at least one illness. The number of injured athletes was highest in the skating sports (n=104), followed by alpine skiing (n=53), ice track (n=37), freestyle skiing (n=36), and ice hockey (n=35), and was the lowest in the Nordic skiing disciplines (n=20). Of the 326 injuries, 14 (4.3%) led to an estimated absence from training or competition of more than 1 week. A total of 52 injured athletes were transferred to hospitals for further care. The number of athletes with illness (n=80) was the highest for skating (n=33) and Nordic skiing (n=22). A total of 50 illnesses (62.5%) were admitted to the department of dentistry/ophthalmology/otolaryngology, and the most common cause of illness was other causes, including preexisting illness and medicine (n=52, 65%). CONCLUSION: Overall, 11% of athletes incurred at least one injury during the Games, which is similar to the findings during the Olympic Winter Games in 2014 and 2018. Regarding illness, 2% of athletes were affected, which is approximately one-third of the number affected in the 2018 Olympic Winter Games.

[Paragonimus skrjabini infection in animal reservoir hosts and questionnairing in residents at a village of Hubei Province].

Freshwater crabs (Sinopotamon denticulatum) were examined for metacercariae. Cats and dogs were also examined for Paragonimus infection. Questionnairing was carried out on health knowledge and behaviors among local residents in a village of Baokang County, Hubei Province. Results showed that the infection rate of Paragonimus skrjabini metacercariae in Sinopotamon denticulatum was 20.5% (46/214), with 15.6% (20/128) in a mining area and 30.2% (26/86) for the non-mining area respectively (chi2 = 6.5, P < 0.05). The prevalence in cats and dogs was 25.0% (6/24) and 17.6% (6/34) respectively (chi2 = 0.46, P > 0.05). Questionnairing showed that dogs and cats were with the habit of foraging and defecating at streams and children had the habits of eating raw or under-cooked crabs. The natural and ecological environments are in favor of the life cycle of P. skrjabini.

N-butylidenephthalide attenuates Alzheimer's disease-like cytopathy in Down syndrome induced pluripotent stem cell-derived neurons.

Down syndrome (DS) patients with early-onset dementia share similar neurodegenerative features with Alzheimer's disease (AD). To recapitulate the AD cell model, DS induced pluripotent stem cells (DS-iPSCs), reprogrammed from mesenchymal stem cells in amniotic fluid, were directed toward a neuronal lineage. Neuroepithelial precursor cells with high purity and forebrain characteristics were robustly generated on day 10 (D10) of differentiation. Accumulated amyloid deposits, Tau protein hyperphosphorylation and Tau intracellular redistribution emerged rapidly in DS neurons within 45 days but not in normal embryonic stem cell-derived neurons. N-butylidenephthalide (Bdph), a major phthalide ingredient of Angelica sinensis, was emulsified by pluronic F127 to reduce its cellular toxicity and promote canonical Wnt signaling. Interestingly, we found that F127-Bdph showed significant therapeutic effects in reducing secreted Aß40 deposits, the total Tau level and the hyperphosphorylated status of Tau in DS neurons. Taken together, DS-iPSC derived neural cells can serve as an ideal cellular model of DS and AD and have potential for high-throughput screening of candidate drugs. We also suggest that Bdph may benefit DS or AD treatment by scavenging Aß aggregates and neurofibrillary tangles.