UV光催化桐油基多元醇的制备及超支化聚氨酯的表征

首先将桐油与甲醇经过酯交换反应得到桐酸甲酯,再将其与过氧化氢和乙酸反应制备环氧桐酸甲酯;然后以三芳基硫金翁盐为催化剂,在UV光条件下催化环氧桐酸甲酯与二乙醇胺开环,制备桐油基多元醇;最后以桐油基多元醇、异佛尔酮二异氰酸酯、甲基丙烯酸羟乙酯等为原料,以二月桂酸二丁基锡为催化剂,经过两步法反应制备了桐油基超支化聚氨酯丙烯酸酯。结果表明,在UV光条件下,三芳基硫金翁盐可以催化环氧桐酸甲酯开环制备桐油基多元醇,其羟基值为599.54 mg KOH/g,相对分子质量为544;以桐油基多元醇为核得到的聚氨酯丙烯酸酯具有良好的光固化活性,以及良好的热稳定性能和力学性能,并且成膜的表面光滑、平整,其玻璃化转变温度为37.2℃,拉伸强度为8.58 MPa,断裂伸长率为23.31%,表面张力为41.36 mJ/m 2。

Chromosome-level genome assembly of Tibetan macaque(Macaca thibetana) and species-specific structural variations

DEAR EDITOR,The Tibetan macaque(Macaca thibetana)is an endemic species in China belonging to the sinica group in the genus Macaca.Within the genus,it is the largest in body size and has a wide geographic distribution,with a population size second only to rhesus macaques(M.mulatta).Here,using PacBio long-read sequencing and Hi-C technology,we assembled the first chromosome-level genome of the Tibetan macaque,with a size of 2.82 Gb,contig N50 of 48.75 Mb,and scaffold N50 of 150.62 Mb,anchored to 22 chromosomes.

First complete genome sequence in Arborophila and comparative genomics reveals the evolutionary adaptation of Hainan Partridge(Arborophila ardens)

Background:The Hainan Partridge(Arborophila ardens,Phasianidae,Galliformes) is an endemic species of Hainan Island,China,and it is classified as globally vulnerable species.There are at least 16 species in genus Arborophila and no genome sequence is available.Methods:The whole genome of Hainan Partridge was de novo sequenced(with shotgun approach on the Illumina 2000 platform) and assembled.Results:The genome size of Arborophila ardens is about 1.05 Gb with a high N50 scaffold length of 8.28 Mb and it is the first high quality genome announced in Arborophila genus.About 9.19% of the genome was identified as repeat sequences and about 5.88 million heterozygous SNPs were detected.A total of 17,376 protein-coding genes were predicted and their functions were annotated.The genome comparison between Hainan Partridge and Red Junglefowl(Gallus gallus) demonstrated a conserved genome structure.The phylogenetic analysis indicated that the Hainan Partridge possessed a basal phylogenetic position in Phasianidae and it was most likely derived from a common ancestor approximately 36.8 million years ago(Mya).We found that the Hainan Partridge population had experienced bottleneck and its effective population decreased from about 1,040,000 individuals 1.5 Mya to about 200,000 individuals 0.2 Mya,and then recovered to about 460,000 individuals.The number of 1:1 orthologous genes that were predicted to have undergone positive selection in the Hainan Partridge was 504 and some environmental adaptation related categories,such as response to ultraviolet radiation were represented in GO distribution analysis.Conclusions:We announced the first high quality genome in Arborophila genus and it will be a valuable genomic resource for the further studies such as evolution,adaption,conservation,not only on Hainan Partridge but also on Arborophila or Phasianidae species.

A case of primary malignant fibrous histiocytoma of the pancreas with liver metastasis

Malignant fibrous histiocytoma(MFH) is one of most common types of soft-tissue sarcoma. However, it accounts for less than 1% of all human cancer types. In addition, primary MFH of the pancreas is very rare. Herein, we report of a 37-year-old man who presented with a pancreatic mass and did not show any specific symptoms. Pre-contrast computed tomography(CT) showed a heterogeneous, liquid-filled necrotic mass in the uncinate lobe of the pancreas. Contrast-enhanced CT showed a mild enhancement of solid components and the pancreaticoduodenal artery across the mass. The patient underwent a pancreaticoduodenectomy, ethanol ablation of the liver lesions, and chemotherapy with 4 cycles of ifosfamide and doxorubicin. The tumor recurred in the liver, but not in the pancreas, after 8 months.

Functional analysis of OAT gene in Aspergillus Niger

Mitochondrial oxaloacetate transporter protein encoded by OAT gene transports oxaloacetate from cytoplasm into mitochondria. To investigate the primary effects of OAT gene on relative metabolism in Aspergillus niger, a oat-deleted mutant was derived from wild-type A. niger ATCC1015 using the double-crossover chromosome replacement technique. Then batch fermentation was performed to evaluate the mutant. Compared with the wild type, the mutant showed lower organic acids production, with the experimental data that the production of pyruvate and 2-ketoglutarate decreased by 31.6% and 35.7%, respectively, and by contrast, the mutant showed higher glycerol formation. The results suggest that OAT gene plays significant roles on metabolism in A. niger.

Real Estate Tax Reform,Economic Growth and Financial Stability

By constructing a multi-sector DSGE model embedded with tax wedge, housing mortgage fi nancing constraints and bank supervision constraints, this paper investigates the long-term impact of two types of real estate tax policies on economic growth and fi nancial stability, which are the unifi ed tax base assessment ratio and differential tax base assessment ratio for two major housing owners (household and enterprises). It also compares and analyzes the short-term impact of the above two types of real estate tax reform schemes on economic fl uctuations and fi nancial risks under the background of potential fi nancial risks facing China’s economy. The results show that: in the long run, the real estate tax will help economic growth, boost household consumption, and effectively suppress the excessive increase in household leverage and asset bubble risk through the “suppression effect” of housing prices and the “redistribution effect” on housing. In the short run, the real estate tax will not intensify the impact of systemic fi nancial risks, so it will not have an adverse impact on the maintenance of fi nancial stability. Different real estate tax policies have different impact on economic growth and fi nancial stability. Compared with the real estate tax with unifi ed tax base assessment ratio, the real estate tax with differential tax base assessment ratio is better for the coordinated development of financial activities and the real economy in the long term and play a stronger role in economic growth, which contributes to the unity of “stable growth”, “risk prevention” and “reform”.