Synthesis of Chiral Bisacylphosphine Oxides and Their Application as Initiators in Helix-Sense-Selective Photopolymerization

Jia-An Zhang,Nian-Fa Yang,Li-Wen Yang,Shi Wu,Ye-Hui Chen,Jin Zhang 한국고분자학회 2013 Macromolecular Research Vol.21 No.6

Three new chiral bisacylphosphine oxides, (-)-bis(menthylformyl)phenylphosphine oxide (1a), (+)-bis(2,4,6-trimethylbenzoyl)menthylphosphine oxide (2a), and (-)-bis(menthylformyl)menthylphosphine oxide (3a),were synthesized using menthol as a chiral source. The synthesized new chiral bisacylphosphine oxides were used as photoinitiators for the polymerization of 1-phenyldibenzosuberyl methacrylate (PDBSMA). The polymerization initiated by chiral bisacylphosphine oxides under UV light irradiation is helix-sense-selective. Among the three prepared chiral bisacylphosphine oxides, the helix-sense-selectivity of bis(menthylformyl)menthylphosphine oxide is highest. The highest specific rotation of poly(1-phenyldibenzosuberyl methacrylate) at 365 nm is +416. The feed molar ratio of monomer to chiral bisacylphosphine oxide and the polymerization temperature have an influence on the helix-sense-selectivity. The lower the feed molar ratio of monomer to chiral bisacylphosphine oxide, the better the helix-sense-selectivity is. The increase of polymerization temperature is propitious to increase the helix-senseselectivity of the photopolymerization.

Test Study on the Air Permeability of Remolded Q3 Malan Loess

Jia Liu,Xi’an Li,Zeze Guo,Quan Xue,Li Wang,Jinyang Liu 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.8

Gas permeability is an important parameter in the determination of the pore structure characteristics of loess, especially in engineering fields such as earthwork and landfill cover treatment. With an improved ZC-2015 air permeameter, the air permeability (ka) testing under different water contents (w), dry densities (ρd) and wetting paths was conducted on remolded Q3 Malan loess from the Chanhe River area in Xi’an, Shaanxi, China. The results indicate that the ka of the remolded loess decreased rapidly as ρd increased and exhibited a relatively complex pattern as w increased. When w was less than the plastic limit (wp) and ρdwas relatively low (1.35 g·cm−3, 1.45 g·cm−3), ka decreased as we increased. When ρd reached a certain value (1.50 g·cm−3, 1.65 g·cm−3), the ka–we curve exhibited a notable turning point. When ρd continued to increase 1.70 g·cm−3, ka decreased as we increased. The results of microscopic analysis, suggested that under the action of different water content and compaction, levels of aggregates and pore structures were formed. A Poulsen model was used to predict the ka and the test results were in relatively coincident with the calculation results, demonstrating that the Poulsen model is applicable.

A Retrospective Study of the Effect of Spinopelvic Parameters on Fatty Infiltration in Paraspinal Muscles in Patients With Lumbar Spondylolisthesis

Jia-Chen Yang,Jia-Yu Chen,Yin Ding,Yong-Jie Yin,Zhi-Ping Huang,Xiu-Hua Wu,Zu-Cheng Huang,Yi-Kai Li,Qing-An Zhu 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion: FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.

Association between FGFRs and the susceptibility of digestive and reproductive system cancers in Chinese population

Jia-Kang Wang,Shu-jun Guo,Bao-qing Tian,Chnag-jun Nie,Hai-long Wang,Jia-lang Wang,An Hong,Xiao-jia Chen 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.4

Fibroblast growth factors(FGFs) and their receptors (FGFRs) modulate a wide range of biological functions, especially tumor genesis. The aim of this study was to investigate the possible association of FGFR expression with the susceptibility of digestive system and reproductive system cancers in Chinese population. In total, 343 patients with digestive or reproductive system cancers were enrolled in this study. The expression levels of four highly-conserved FGFRs including FGFR1, FGFR2, FGFR3 and FGFR4 were measured by immunohistochemistry (IHC). The expression levels of FGFRs were compared between carcinoma and para-carcinoma tissues. FGFR1 expression significantly differed between carcinoma and para-carcinoma tissues in colon and gastric cancers. FGFR2 expression significantly differed between carcinoma and para-carcinoma tissues in esophageal cancer. FGFR3 expression was significantly different between carcinoma and para-carcinoma tissues in liver and gastric cancers. FGFR2 showed the highest expression probability in all the selected cancers and FGFR4 showed the lowest expression probability. FGFR1 and FGFR3 showed comparable moderate expression probabilities. Our findings have demonstrated significant differences regarding FGFR expression levels between carcinoma and para-carcinoma cells in digestive or reproductive system cancer patients. The data also implicated that FGFR2 and FGFR4 could serve as two prominent factors closely related to the susceptibility of digestive and reproductive system cancers.

Developments of double skin composite walls using novel enhanced C-channel connectors

Jia-Bao Yan,An-Zhen Chen,Tao Wang 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.6

The developments of double skin composite (DSC) walls with novel enhanced C-channel connectors (DSCW-EC) were reported. Followed axial compression tests on prototype walls were carried to evaluate structural performances of this novel DSC composite structures. The testing program consists of five specimens and focused on the layout of the novel enhanced C-channel (EC) connectors, which include the web direction of C-channels, steel-faceplate thickness, vertical and horizontal spacing of Cchannels. Crushing in concrete core and buckling of steel faceplate were two main observed failed modes from the compression tests. However, elastic or plastic buckling of the steel faceplate varies with designed parameters in different specimens. The influences of those investigated parameters on axial compressive behaviors of DSCW-ECs were analyzed and discussed. Recommendations on the layout of novel EC connectors were then given based on these test results and discussions. This paper also developed analytical models for predictions on ultimate compressive resistance of DSCW-ECs. Validation against the reported test results show that the developed theoretical models predict well the ultimate compressive resistance of DSCW-ECs.

Cloning, Expression, and Characterization of Serine Protease from Thermophilic Fungus Thermoascus aurantiacus var. levisporus

An-Na Li,Chen Xie,Jie Zhang,Jia Zhang,Duo-Chuan Li 한국미생물학회 2011 The journal of microbiology Vol.49 No.1

The serine protease gene from a thermophilic fungus Thermoascus aurantiacus var. levisporus, was cloned,sequenced, and expressed in Pichia pastoris and the recombinant protein was characterized. The full-length cDNA of 2,592 bp contains an ORF of 1,482 bp encoding 494 amino acids. Sequence analysis of the deduced amino acid sequence revealed high homology with subtilisin serine proteases. The putative enzyme contained catalytic domain with active sites formed by three residues of Asp183, His215, and Ser384. The molecular mass of the recombinant enzyme was estimated to be 59.1 kDa after overexpression in P. pastoris. The activity of recombinant protein was 115.58 U/mg. The protease exhibited its maximal activity at 50°C and pH 8.0 and kept thermostable at 60°C, and retained 60% activity after 60 min at 70°C. The protease activity was found to be inhibited by PMSF, but not by DTT or EDTA. The enzyme has broad substrate specificity such as gelatin, casein and pure milk, and exhibiting highest activity towards casein.

Curcumin targets vascular endothelial growth factor via activating the PI3K/Akt signaling pathway and improves brain hypoxic-ischemic injury in neonatal rats

Jia Li,Yan An,Jia-Ning Wang,Xiao-Ping Yin,Huan Zhou,Yong-Sheng Wang 대한생리학회-대한약리학회 2020 The Korean Journal of Physiology & Pharmacology Vol.24 No.5

This study aimed to evaluate the effect of curcumin on brain hypoxicischemic (HI) damage in neonatal rats and whether the phosphoinositide 3-kinase (PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved. Brain HI damage models were established in neonatal rats, which received the following treatments: curcumin by intraperitoneal injection before injury, insulin-like growth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricular injection after injury. This was followed by neurological evaluation, hemodynamic measurements, histopathological assessment, TUNEL assay, flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt, Akt, and VEGF. Compared with rats that underwent sham operation, rats with brain HI damage showed remarkably increased neurological deficits, reduced right blood flow volume, elevated blood viscosity and haematocrit, and aggravated cell damage and apoptosis; these injuries were significantly improved by curcumin pretreatment. Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF, while curcumin pretreatment inhibited the expression of these proteins. In addition, IGF-1 treatment rescued the curcumin-induced down-regulated expression of p- PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effect of curcumin on brain HI damage. Overall, pretreatment with curcumin protected against brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway in neonatal rats.

A NEW LOOK AT THE FUNDAMENTAL THEOREM OF ASSET PRICING

Yan, Jia-An Korean Mathematical Society 1998 대한수학회지 Vol.35 No.3

In this paper we consider a security market whose asset price process is a vector semimartingale. The market is said to be fair if there exists an equivalent martingale measure for the price process, deflated by a numeraire asset. It is shown that the fairness of a market is invariant under the change of numeraire. As a consequence, we show that the characterization of the fairness of a market is reduced to the case where the deflated price process is bounded. In the latter case a theorem of Kreps (1981) has already solved the problem. By using a theorem of Delbaen and Schachermayer (1994) we obtain an intrinsic characterization of the fairness of a market, which is more intuitive than Kreps' theorem. It is shown that the arbitrage pricing of replicatable contingent claims is independent of the choice of numeraire and equivalent martingale measure. A sufficient condition for the fairness of a market, modeled by an Ito process, is given.

Molecular Cloning of Two Genes Encoding Cinnamate 4-Hydroxylase (C4H) from Oilseed Rape (Brassica napus)

Chen, An-He,Chai, You-Rong,Li, Jia-Na,Chen, Li Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.2

Cinnamate 4-hydroxylase (C4H) is a key enzyme of phenylpropanoid pathway, which synthesizes numerous secondary metabolites to participate in development and adaption. Two C4H isoforms, the 2192-bp BnC4H-1 and 2108-bp BnC4H-2, were cloned from oilseed rape (Brassica napus). They both have two introns and a 1518-bp open reading frame encoding a 505-amino-acid polypeptide. BnC4H-1 is 57.73 kDa with an isoelectric point of 9.11, while 57.75 kDa and 9.13 for BnC4H-2. They share only 80.6% identities on nucleotide level but 96.6% identities and 98.4% positives on protein level. Showing highest homologies to Arabidopsis thaliana C4H, they possess a conserved p450 domain and all P450-featured motifs, and are identical to typical C4Hs at substrate-recognition sites and active site residues. They are most probably associated with endoplasmic reticulum by one or both of the N- and C-terminal transmembrane helices. Phosphorylation may be a necessary post-translational modification. Their secondary structures are dominated by alpha helices and random coils. Most helices locate in the central region, while extended strands mainly distribute before and after this region. Southern blot indicated about 9 or more C4H paralogs in B. napus. In hypocotyl, cotyledon, stem, flower, bud, young- and middle-stage seed, they are co-dominantly expressed. In root and old seed, BnC4H-2 is dominant over BnC4H-1, with a reverse trend in leaf and pericarp. Paralogous C4H numbers in Brassicaceae genomes and possible roles of conserved motifs in 5' UTR and the 2nd intron are discussed.

Histological Changes of Tissues and Cell Wall of Rice Straw Influenced by Chemical Pretreatments

Wang, Jia-Kun,Chen, Xiao-Lian,Liu, Jian-Xin,Wu, Yue-Ming,Ye, Jun-An Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.6

Sodium hydroxide (SH) or ammonium bicarbonate (AB) were applied to rice straw to investigate the effects on histological change of stem tissue or cell wall before and after in sacco degradation using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The SEM revealed that, the parenchyma and vascular bundles were distorted by treatment with SH at 30 or 45 g/kg straw dry matter. Faultage between phloem of large vascular bundles and parenchyma occurred with further increasing SH to 60 or 75 g/kg. The cell wall in these stem tissues was crimped when observed by TEM. However, only parenchyma and large vascular tissues were slightly distorted in AB-treated stem. For untreated and AB-treated stems, the initiation of observable ruminal degradation of cell wall was prolonged from 12 h for inner parenchyma to 24 h for sclerenchyma and to 48 h for phloem of small vascular bundles, while the outer epidermis was intact even at 72 h. For SH-treated stem, however, the cell wall from all of the investigated tissues, epidermis, small vascular bundles, sclerenchyma, and parenchyma started to be degraded at 12 h incubation. These results indicate that SH treatment contracts rice straw stem leading to an improvement in rumen degradation, and that the degradation of SH-treated stem is bilateral from inner and outer surface simultaneously.