[The characteristics and change trends of air pollutants in Lanzhou City from 2014 to 2020].

OBJECTIVE: To study the distribution characteristics of atmospheric pollutants and their correlation with meteorological factors. METHODS: The PM_(2.5), PM_(10), NO_2, SO_2, O_(3-1 h), O_(3-8 h) and CO daily average concentration data from 2014 to 2020 were obtained from Lanzhou Environmental Protection Bureau. The interannual changes of pollutants, monthly changes, seasonal changes and trend of spatial distribution were analysed. Spearman correlation analysis was performed on the relationship among pollutants. RESULTS: The main pollutants exceeding the standard in Lanzhou from 2014 to 2020 were PM_(10), PM_(2.5) and NO_2, average annual concentration of PM_(10), PM_(2.5), NO_2 and CO were decreasing year by year, and O_3 was increasing year by year. The monthly average concentration of PM_(10) was the highest in December, January, March and November were the second highest, and it was higher in February, April and May. The monthly change trends of PM_(2.5), NO_2, SO_2 and CO concentrations were the same, and the monthly change trends of the 1 hour average and daily maximum 8-hour average concentrations of O_3 were the same. The seasonal variation of atmospheric pollutant concentration was obvious, the concentrations of PM_(10), PM_(2.5), SO_2, NO_(2 )and CO were the highest in winter and the lowest in summer. O_3 concentration was the highest in summer and lowest in winter. Average annual concentration of 6 pollutants in different regions had statistically significant differences(H=750.40, 1112.99, 1410.05, 352.04, 360.17, 619.20, 729.52; P<0.001). Among them, the average annual concentration of PM_(10), PM_(2.5), SO_(2 )and O_(3-1 h) in Xigu District were the highest. PM_(10), PM_(2.5), NO_2, SO_2, CO average annual concentration were negatively correlated with temperature and wind speed(r_s=-0.423, -0.561, -0.395, -0.660, -0.569, -0.043, -0.094, -0.130, -0.172, -0.135), the concentration of PM_(10), PM_(2.5), O_3, SO_2 concentration were negatively correlated with humidity(r_s=-0.238, -0.121, -0.110, -0.094), only O_3 was positively correlated with temperature(r_s=0.486). CONCLUSION: The primary pollutants in Lanzhou from 2014 to 2020 were PM_(10), PM_(2.5) and NO_2.O_3 had an obvious upward trend year by year. The 6 pollutants had obvious seasonal changes and regional distribution characteristics. Some pollutants had the same homology, and meteorological factors affected each pollution. The concentration of the substance had an important influence. Relevant air pollution control measures should be formulated based on the main excessive pollutants, the monthly change trend of air pollution and the seasonal pollution characteristics, the same emission sources and geographical distribution characteristics should be considered, and the meteorological factors should be combined.

Identification of a linear epitope within domain I of Duck Tembusu virus envelope protein using a novel neutralizing monoclonal antibody.

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that caused severe egg drop syndrome in laying ducks in China since 2010, leading to massive economic losses to the duck industry. Although the DTMUV E protein is considered to be critical in inducing the protective immune response, the functional epitopes within this protein remain largely unknown. In the present study, we isolated a DTMUV neutralizing monoclonal antibody (mAb) 3B8 from DTMUV E-immunized mice. Epitope mapping showed that mAb 3B8 recognized a novel linear epitope FSCLGMQNR located on the extreme N-terminal of the domain I (EDI) of E protein. Sequence alignment and Western blot analyses showed that the epitope is greatly conserved with high DTMUV-specificity. Moreover, upon cloning the heavy and light chain variable region sequences of mAb 3B8, we prepared the single-chain variable antibody fragment (scFv) 3B8 by connecting the two chains via a flexible peptide linker. The recombinant scFv 3B8 exhibited antiviral activity against DTMUV infection in vitro and in vivo. Our results provide valuable implications for the development of DTMUV vaccines and therapeutics.

[Pollution characteristics and health risk assessment of polycyclic aromatic hydrocarbons in fine particulate matter in Lanzhou community].

OBJECTIVE: To understand the pollution level of polycyclic aromatic hydrocarbons(PAHs) in community fine particulate matter(PM_(2. 5)) in Lanzhou community, and assess the risk of cancer. METHODS: Samples of atmospheric fine particles were collected in communities A and B of Lanzhou City from 10 to 16 of each month in 2018. The mass concentration and composition of 16 kinds of optimal control to the EPA PAHs, such as naphthalene(Nap), acenaphthylene(Acy), philippines(Phe), acenaphthene(Ace), fluorene(FI), anthracene(Ant), fluoranthene(Flu), pyrene(Pyr), chrysene(Chr), benzo(a) anthracene(BaA), benzene(b) fluoranthracene(BbF), benzene(k) fluoranthracene(BkF), benzo(a) pyrene(BaP), dibenzene(a, h) anthracene(DahA), benzene(g, h, i) perylene(BghiP) and indene(1, 2, 3-cd)pyrene(IcdP), were analysed, and the toxicity were assessed by toxicity equivalent concentration and lifetime excess carcinogenic risk(ECR). RESULTS: The annual average PM_(2. 5) concentrations in community A and B were 70 µg/m~3, 2 times the national standard. The average annual PAHs concentrations in community A and B were 113. 56(5. 22-485. 71) and 55. 68(2. 39-257. 43) ng/m~3, respectively. In addition, in winter, spring and autumn, the PAHs of the two communities were mainly 3-5 rings, 3-ring and 6-ring PAHs were the main components in summer. The result of feature ratio method were shown that BaP of 16 kinds of PAHs was the equivalent mass concentration(BaPeq) range of 0. 00017-3. 19 ng/m~3, ΣBaPeqin community A and B were 7. 64 and5. 11 ng/m3, respectively. BaP and DahA were the most toxic, All of them contributed more than 70% to ΣBaPeq, the total ECR of Σ16 PAHs in community A and B were 6. 64×10~(-4) and 4. 44×10~(-4), respectivel. CONCLUSION: BaP and DahA have certain potential health risks to residents in communities a and B of Lanzhou.

[Molecular cloning and characterization of CMK from Artemisia annua].

Artemisinin is a preferred medicine in the treatment of malaria. In this study, AaCMK, a key gene involved in the upstream pathway of artemisinin biosynthesis, was cloned and characterized from Artemisia annua for the first time. The full-length cDNA of AaCMK was 1 462 bp and contained an ORF of 1 197 bp that encoded a 399-anomo-acid polypeptide. Tissue expression pattern analysis showed that AaCMK was expressed in leaves, flowers, roots and stems, but with higher expression level in glandular secretory trichomes. In addition, the expression of AaCMK was markedly increased after MeJA treatment. Subcellular localization showed that the protein encoded by AaCMK was localized in chloroplast. Overexpression of AaCMK in Arabidopsis increased the contents of chlorophyll a, chlorophyll b and carotenoids. These results suggest that AaCMK plays an important role in the biosynthesis of terpenoids in A. annua and this research provids a candidate gene that could be used for engineering the artemisinin biosynthesis.

A Root-Preferential DFR-Like Gene Encoding Dihydrokaempferol Reductase Involved in Anthocyanin Biosynthesis of Purple-Fleshed Sweet Potato.

Purple-fleshed sweet potato is good for health due to rich anthocyanins in tubers. Although the anthocyanin biosynthetic pathway is well understood in up-ground organs of plants, the knowledge on anthocyanin biosynthesis in underground tubers is limited. In the present study, we isolated and functionally characterized a root-preferential gene encoding dihydrokaempferol reductase (IbDHKR) from purple-fleshed sweet potato. IbDHKR showed highly similarity with the reported dihydroflavonol reductases in other plant species at the sequence levels and the NADPH-binding motif and the substrate-binding domain were also found in IbDHKR. The tissue profile showed that IbDHKR was expressed in all the tested organs, but with much higher level in tuber roots. The expression level of IbDHKR was consistent with the anthocyanin content in sweet potato organs, suggesting that tuber roots were the main organs to synthesize anthocyanins. The recombinant 44 kD IbDHKR was purified and fed by three different dihydroflavonol substrates including dihydrokaempferol (DHK), dihydroquerctin, and dihydromyrecetin. The substrate feeding assay indicated that only DHK could be accepted as substrate by IbDHKR, which was reduced to leucopelargonidin confirmed by LC-MS. Finally, IbDHKR was overexpressed in transgenic tobacco. The IbDHKR-overexpression tobacco corolla was more highly pigmented and contained higher level of anthocyanins than the wild-type tobacco corolla. In summary, IbDHKR was a root-preferential gene involved in anthocyanin biosynthesis and its encoding protein, specifically catalyzing DHK reduction to yield leucopelargonidin, was a candidate gene for engineering anthocyanin biosynthetic pathway.

Molecular cloning and functional characterization of duck mitochondrial antiviral-signaling protein (MAVS).

Mitochondrial antiviral-signaling protein (MAVS), also called IPS-1/VISA/Cardif, is an important molecule involved in host defense and triggers a signal for producing type I IFN. Currently the function of MAVS in ducks (duMAVS) remains largely unclear while significant progress has been made in mammals. In this study, the full-length duMAVS cDNA was cloned from duck embryo fibroblasts (DEFs) for the first time. Tissue specificity analysis showed duMAVS was universally expressed in all detected tissues. DEFs transfected with duMAVS were able to induce interferon-ß (IFN-ß) expression through activating interferon regulatory factor 1 (IRF1) and nuclear factor kappa B (NF-κB). Both the CARD-like domain and transmembrane domain were required for duMAVS signaling via deletion mutant analysis. In addition, poly(I:C)- or Sendai virus (SeV)-induced IFN-ß expression in DEFs were significantly decreased by knock-down of duMAVS with siRNA. Altogether, these results indicate that MAVS is a critical immunoregulator in duck innate immune system.

Clinicopathologic features of familial nonmedullary thyroid carcinoma.

BACKGROUND: Familial nonmedullary thyroid carcinoma (FNMTC) is a variant of nonmedullary thyroid carcinoma(NMTC) with particular clinicopathologic features. In recent years, a number of studies have shown that FNMTC is more invasive than sporadic NMTC(SNMTC). The purpose of this study was to explore the differences in clinicopathologic features of FNMTC between different types of families and to determine in which of these families more invasive FNMTC occurred. METHODS: We retrospectively reviewed all patients with thyroid carcinoma admitted to Peking Union Medical College Hospital from January 2009 to July 2013 in the database. Of all 2000 cases, 55 met the inclusive criteria for FNMTC and were studied. There are two different grouping methods. The first is that all samples were allocated to families with three or more first-degree relatives affected (FNMTC-3 group) and families with only two affected first-degree relatives (FNMTC-2 group). The second is that all patients were divided into families with three or more affected first-degree relatives over two generations (FNMTC-3-2 group) and the other families. We compared the clinicopathologic features such as sex, age, tumor size, multifocality, location, complications by thyroiditis, complications by benign thyroid nodules, surgical procedure, capsule invasion, histological type, lymph node metastases, tumor node metastasis stage, and BRAF mutation between FNMTC-2 group and FNMTC-3 group. We also made the same comparison between FNMTC-3-2 group and other families. RESULTS: No pronounced differences in clinicopathological features were present between FNMTC-2 group and FNMTC-3 group. The proportion of FNMTC-3-2 group aged <45 years was significantly higher than that in the other families (58.8% vs. 26.3%, P = 0.021). A similar difference was found in the proportion of lymph node metastasis (64.7% vs. 34.2%, P = 0.035). CONCLUSIONS: FNMTC-3-2 is more invasive than the other families. Early screening and positive treatment for members of these families are recommended.