[Source Analysis and Health Risk Assessment of PAHs in PM2.5, Lüliang City].

To investigate the seasonal variation, health risks, and potential sources of polycyclic aromatic hydrocarbons(PAHs) in PM2.5 in the Lüliang area, PM2.5 samples were collected in Lishi District(downtown area) and Xiaoyi City(suburban area) from October 23, 2018 to July 1, 2019, and the concentrations of 14 PAHs were determined using gas chromatography-mass spectrometry(GC-MS). The annual average concentration of PAHs was 95.50 ng·m-3, and the concentration of 5-6 ring PAHs was mainly(49.7%), with 3 ring PAHs accounting for a relatively low proportion(8.3%).The concentration of PAHs in Lüliang City showed a seasonal pattern of winter>autumn>spring>summer. The results of the ILCRs model and Monte Carlo simulation showed that the toxicity of PAHs in Lüliang City followed the rule of adults>youth>children. Except in summer, the ILCRs values in the Lishi area were between 10-6 and 10-4, much higher than those in Xiaoyi City, indicating that there was a high potential risk of polycyclic aromatic hydrocarbons in the urban area. Through the characteristic ratio method and positive matrix factorization(PMF), it was shown that the PAHs in Lüliang City were mainly from the combustion of coal and biomass(61.9%) and vehicle exhaust emissions(38.1%). Based on the backward trajectory and potential source factor contribution analysis model, it was determined that the potential sources of PAHs in Lüliang City were mainly distributed in southern Shanxi, northern Shaanxi, and western Inner Mongolia.

Effect of neurotropin on Alzheimer's disease-like changes and cognitive function in rats with chronic cerebral hypoperfusion.

Chronic cerebral hypoperfusion (CCH) is a main mechanism of cerebrovascular disease and is associated with various cerebrovascular and neurodegenerative diseases, including Alzheimer's disease. However, treatment of CCH in clinical practice is not ideal, but neurotropin (NTP) has been shown to have a neuroprotective effect. Therefore, this study examined the effect and possible mechanism of NTP in nerve injury caused by CCH. A rat CCH model was established by bilateral common carotid artery occlusion (2VO), and rats were treated with intragastric administration of NTP (200 nu/kg/day) for 28 consecutive days. After treatment, rats were subjected to the Morris water maze and novel object recognition test. Subsequently, an ELISA was applied to detect amyloid-ß (Aß) 1-40 and Aß1-42 levels in rat hippocampal tissues, quantitative reverse transcription PCR assays were used to detect the mRNA expression levels of brain-derived neurotrophic factor (BDNF) and Trk B, and Western blots were used to detect the protein expression levels of BACE1, tau, p-tau, and protein kinase B (Akt)/glycogen synthase kinase 3ß (GSK3ß) pathway-related proteins. The rat model of CCH was successfully established by 2VO. Behavioral tests indicated that the cognitive ability of 2VO rats was severely impaired. NTP treatment greatly ameliorated the cognitive disability, reduced Aß1-40 and Aß1-42 levels and tau phosphorylation, and upregulated BACE1, Trk B, and BDNF expression in the hippocampus of 2VO rats. Finally, we found that NTP markedly activated Akt/GSK3ß pathway activity. NTP can ameliorate cognitive disability in CCH rats possibly by reducing Aß accumulation and tau phosphorylation in the hippocampus. These effects of NTP may be related to the Akt/GSK3ß pathway activation. NTP may be a promising new drug candidate for CCH patients.

A new species of Notacanthella Jacobus & McCafferty, 2008 (Ephemeroptera, Ephemerellidae) from Yunnan, China.

Notacanthellajinwu Li & Jacobus, sp. nov. is described based on egg, nymph, and winged stages from Dali Bai Autonomous Prefecture, Yunnan Province, China. The nymph of the new species is closely related to N.commodema (Allen, 1971), whose nymphs share a similar tuberculation of head, pronotum, and mesonotum. However, the nymph of our new species can be distinguished based on the structures of male sternum IX and abdominal tergal tubercles. In addition, the new species is distributed in subtropical high-altitude areas. The description of the male imago of the new species is the first certain one for the genus Notacanthella. Data associated with our new species allow for expanded discussion and diagnosis of Notacanthella and closely related genera. An identification key for nymphs of these groups is provided.

Hybrid Palladium Catalyst Assembled from Chiral Phosphoric Acid and Thioamide for Enantioselective ß-C(sp3 )-H Arylation.

A hybrid palladium catalyst assembled from a chiral phosphoric acid (CPA) and thioamide enables a highly efficient and enantioselective ß-C(sp3 )-H functionalization of thioamides (up to 99 % yield, 97 % ee). A kinetic resolution of unsymmetrical thioamides by intermolecular C(sp3 )-H arylation can be achieved with high s-factors. Mechanistic investigations have revealed that stereocontrol is achieved by embedding the substrate in a robust chiral cavity defined by the bulky CPA and a neutral thioamide ligand.

Graphene oxide enhanced ozonation of 5-chloro-2-methyl-4-isothiazolin-3-one: Kinetics, degradation pathway, and toxicity.

Kathon is among the most common non-oxidative biocides, containing 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and methylisothiazolone (MIT) as the active ingredients. In our previous work, MIT was shown to be efficiently removed by ozonation. In this work, we found that ozonation didn't readily degrade CMIT. Rate constants [Formula: see text] and k·OH,CMIT, determined to be 6.43 L mol-1 s-1 and 7.8 × 109 L mol-1 s-1, indicated that hydroxyl radicals played a more important role than ozone molecule in the CMIT ozonation which was also proved by the significant inhibition (55.7 %) when adding t-butanol (TBA). Graphene oxide (GO) greatly enhanced the CMIT ozonation, and degradation efficiency raised from 15 % to 100 % after 10 min through the increased production of hydroxyl radical. Basic conditions benefited the CMIT degradation compared with acidic and neutral conditions by promoting ozone decomposition and hydroxyl radical generation, while high carbonate and humic acid concentrations had slight influence on the CMIT degradation. In spite of the complex water matrix, CMIT degradation by GO enhanced ozonation was applicable in reverse osmosis concentrate (ROC). Based on the identification of the inorganic and organic products, a possible CMIT degradation pathway was proposed. However, CMIT transformation products still showed toxicity to Photobacterium phosphoreum and Daphnia magna even after a longer ozonation time.