Publications by authors named "L An"

2,222 Publications

  • Page 1 of 1

Facile synthesis of core\shell [email protected](Hb) and its application for organic wastewater treatment.

Environ Res 2021 Jul 30:111796. Epub 2021 Jul 30.

College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, China; College of Life Sciences, Northeast Agricultural University, Harbin, China. Electronic address:

Treatment of organic wastewater is a challenging task. Biological techniques using biocatalysts have shown their benefits in organic wastewater treatment. In this research, a novel biocatalyst was developed by encapsulation of Fe3O4 microspheres and haemoglobin (Hb) with mesoporous silica, named [email protected](Hb). [email protected](Hb) exhibited typical mesoporous characteristics (mesoporous silica), magnetic feature (Fe3O4) and peroxidase activity (Hb). The results showed that the immobilization of Hb into [email protected] did not affect its activity. In addition, [email protected](Hb) exhibited a higher efficiency in the peroxidation of aromatic compounds than free Hb. The peroxidase activity of the synthesized biocatalyst was estimated to be 120 Ug, which was almost four times greater than that of previously reported immobilized Hb. Also, the Km of [email protected](Hb) was similar to that of the free Hb and it was estimated to be 4.3 × 10 μM, indicating that the activity of the Hb in the immobilized enzyme was not affected after immobilization. The immobilized enzyme was also found to be stable, recyclable and reusable. Taken together, these results indicate that the [email protected](Hb) has good potential to be used for treating organic wastewater containing aromatic compounds. The magnetically separable novel biocatalyst developed in this study provided not only a more suitable microenvironment for retaining the activity of Hb, but also demonstrated enhanced stability and activity under unfavorable conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.envres.2021.111796DOI Listing
July 2021

Requirements of Postnatal proBDNF in the Hippocampus for Spatial Memory Consolidation and Neural Function.

Front Cell Dev Biol 2021 15;9:678182. Epub 2021 Jul 15.

Behavioral Neuroscience Laboratory, The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China.

Mature brain-derived neurotrophic factor (BDNF) and its downstream signaling pathways have been implicated in regulating postnatal development and functioning of rodent brain. However, the biological role of its precursor pro-brain-derived neurotrophic factor (proBDNF) in the postnatal brain remains unknown. The expression of hippocampal proBDNF was blocked in postnatal weeks, and multiple behavioral tests, Western blot and morphological techniques, and neural recordings were employed to investigate how proBDNF played a role in spatial cognition in adults. The peak expression and its crucial effects were found in the fourth but not in the second or eighth postnatal week. Blocking proBDNF expression disrupted spatial memory consolidation rather than learning or memory retrieval. Structurally, blocking proBDNF led to the reduction in spine density and proportion of mature spines. Although blocking proBDNF did not affect N-methyl-D-aspartate (NMDA) receptor (NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subunits, the learning-induced phosphorylation of the GluN2B subunit level declined significantly. Functionally, paired-pulse facilitation, post-low-frequency stimulation (LFS) transiently enhanced depression, and GluN2B-dependent short-lasting long-term depression in the Schaffer collateral-CA1 pathway were weakened. The firing rate of pyramidal neurons was significantly suppressed around the target region during the memory test. Furthermore, the activation of GluN2B-mediated signaling could effectively facilitate neural function and mitigate memory impairment. The findings were consistent with the hypothesis that postnatal proBDNF played an essential role in synaptic and cognitive functions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcell.2021.678182DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8319730PMC
July 2021

Aggravates Calcium Oxalate Stone Formation via PPK1/Flagellin-Mediated Renal Oxidative Injury and Inflammation.

Oxid Med Cell Longev 2021 13;2021:9949697. Epub 2021 Jul 13.

Department of Urology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 510260, China.

() is closely associated with the formation of kidney stones. However, the role of in CaOx stone formation is not well understood. We explored whether facilitate CaOx stone formation and its mechanism. Stone and urine cultures were reviewed from kidney stone formers. The ability of calcium oxalate monohydrate (COM) aggregation was detected to evaluate the influence of uropathogenic , then gel electrophoresis and nanoLC-MS/MS to detect the crystal-adhered protein. Flagellin (Flic) and polyphosphate kinase 1 (PPK1) were screened out following detection of their role on crystal aggregation, oxidative injury, and inflammation of HK-2 cell . By transurethral injection of wild-type, mutant and mutant strains of and intraperitoneally injected with glyoxylate in C57BL/6J female mice to establish an animal model. We found that was the most common bacterial species in patients with CaOx stone. It could enhance CaOx crystal aggregation both and Flagellin was identified as the key molecules regulated by PPK1, and both of them could facilitate the crystal aggregation and mediated HK-2 cell oxidative injury and activated the inflammation-related NF-B/P38 signaling pathway. Wild-type strain of injection significantly increased CaOx deposition and enhanced oxidative injury and inflammation-related protein expression, and this effect could be reversed by or mutation. In conclusion, promotes CaOx stone formation via enhancing oxidative injury and inflammation regulated by the PPK1/flagellin, which activated NF-B/P38 pathways, providing new potential drug targets for the renal CaOx calculus precaution and treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2021/9949697DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8292073PMC
July 2021

The effects of subway openings on air quality: evidence from China.

Environ Sci Pollut Res Int 2021 Jul 30. Epub 2021 Jul 30.

School of Business, Hubei University, 368 Youyi Avenue, Wuhan, 430062, Hubei, China.

This paper examines a causal relationship between the opening of a city's subway system and its air quality by exploiting daily data on prefecture-level cities in China from 2000 to 2012. Using multi-period difference in differences (DID) method, we find that air quality can be significantly improved following a subway system opening. Robustness tests support the fundamental empirical results. Heterogeneity analysis shows that cities in the eastern and western regions and cities with higher GDP or cities with larger population experience greater and more significant reduction in pollution. We further find that the air pollution continues to decrease with the extension and prolonged operating period of a subway system. Mechanism analysis shows that the resulted air pollution index (API) reduction is due to the substitution effect of taxi.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-021-15482-1DOI Listing
July 2021

Microplastic characteristics in organisms of different trophic levels from Liaohe Estuary, China.

Sci Total Environ 2021 May 26;789:148027. Epub 2021 May 26.

State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China. Electronic address:

Microplastics are a growing concern globally due to their small size and easy ingestion by terrestrial and aquatic organisms, resulting in potential adverse impacts on wildlife. However, current data regarding microplastics in wild organisms in different trophic levels is limited. This study investigated microplastic characteristics, including their abundance, size, shape and polymer type, in estuarine invertebrates and vertebrates. Resultantly, polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) were the predominant microplastics found, as confirmed by a Fourier transform infrared spectrometer (FT-IR). An average microplastic abundance of 0.83 ± 0.99 to 3.87 ± 2.18 items/individual was detected across all species, including sandworm, mollusks, crustacean and fish, but they were not found in all individuals. Microplastics ranged from 52 μm to 5392 μm in size, and the shapes were consisted of fiber, fragment, and pellet. Moreover, the detection ratio (91.95%) and abundance (3.34 ± 2.17 items/individual) of microplastics in fish were significantly higher than in sandworm (42.86%, 0.88 ± 1.04 items/individual), mollusks (66.97%, 1.42 ± 1.41 items/individual) and crustaceans (66.66%, 1.33 ± 1.32 items/individual) (p < 0.05). Furthermore, a positive relationship was identified between microplastic abundance and the trophic level of organisms. These findings imply that microplastics might transfer along the food chain and accumulate at organisms in higher trophic levels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.148027DOI Listing
May 2021
-->