Synthesis and Characterization of pH and Temperature Sensitive Hydrogel Based on Poly(N-isopropylacrylamide), Poly(ε-caprolactone), Methylacrylic Acid, and Methoxyl Poly(ethylene glycol)

Xu Xu,Jia Song,Ke Wang,YingChun Gu,Feng Luo,XiaoHai Tang,Ping Xie,ZhiYong Qian 한국고분자학회 2013 Macromolecular Research Vol.21 No.8

In this paper, a novel biodegradable and pH/thermo-sensitive hydrogel based on poly(ε-caprolactone),methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide was prepared by UV-initiated free radical polymerization. The hydrogels were characterized by Fourier transforms infrared ray. The thermal responsibility was investigated with the help of differential scanning calorimetry. Swelling behavior in aqueous medium with different pH value was studied in detail. When the pH value of the aqueous medium was increased from 1.2 to 7.2,the swelling ratio of the hydrogels increased accordingly. The morphology was observed by scanning electron microscopy, and the hydrolytic degradation behavior in different aqueous media (pH 1.2 and pH 7.2) was also investigated in detail. The prepared biodegradable pH/thermo-sensitive hydrogel based on poly(ε-caprolactone), methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide hold great promise in the development of a smart drug delivery system.

Molecular characterization and functional analysis of two trehalose transporter genes in the cabbage beetle, Colaphellus bowringi

Li Jia-Xu,Cao Zhen,Guo Shuang,Tian Zhong,Liu Wen,Zhu Fen,Wang Xiao-Ping 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.3

The trehalose, major blood sugar in insects, enhances stress resistance of diapausing individuals in adverse environment and provides an energy source for reproduction. Trehalose transporters (TRETs) play an important role in transport of trehalose from trehalose-producing tissues, e.g. fat body, to trehalose-consuming tissues. Although studies have shown that trehalose contributes to diapause and reproduction, the function of TRETs in these processes remains unclear. In this work, we cloned two TRET genes, TRET1a and TRET1b, from the cabbage beetle Colaphellus bowringi, which is capable of entering reproductive diapause under long-day conditions. We also analyzed the expression profiles of these two genes and investigated their potential roles in diapause and reproduction. The results suggested that both TRET1a and TRET1b belong to sugar-transporter and major facilitator superfamilies. Interestingly, TRET1a was highly expressed in the fat bodies of diapause-destined (DD) females but TRET1b was predominantly expressed in the ovaries of non-diapause-destined (NDD) females. Hormonal induction indicated that juvenile hormone induced TRET1b but repressed TRET1a at transcriptional levels. Methoprene-tolerant and Krüppel homolog 1 mediated the JH-suppressed TRET1a expression but were not involved in the regulation of TRET1b expression by JH. RNAi of TRET1a in DD females elevated the trehalose content in the fat bodies and suppressed the expression of a couple of genes related to stress resistance, which is a critical diapause trait. Knockdown of TRET1b in NDD females reduced the trehalose content in the ovaries but had no apparent effect on the ovary development and yolk deposition. These data suggest that TRET1a and TRET1b could regulate the trehalose content in specific tissues and may play potential roles in reproductive diapause in the females of C. bowringi. Introduction Diapause is a survival strategy for many insects in adapting to adverse environmental conditions (Tauber and Tauber, 1976; Tougeron, 2019). Diapause is a dynamic successive process that consists of diapause induction, preparation, initiation, maintenance, termination, and post-diapause quiescence (Kostal, 2006). Insects accumulate enormous nutrients such as sugars and lipids to enter diapause during diapause preparation phase (Hahn and Denlinger, 2007, 2011). The trehalose is the major hemolymph sugar in insects. The sugar not only provides source of energy but also protects proteins and cellular membranes from dehydration, desiccation, heat, cold, and oxidation (Elbein et al., 2003; Li et al., 2002; Richards et al., 2002; Wyatt and Kalf, 1957; Yancey, 2005; Zhu et al., 2008). Therefore, trehalose can play roles in reproduction and diapause by mediating energy supply and stress tolerance, respectively (Kamei et al., 2011; Lu et al., 2019; Xu et al., 2009).

MLH1 Polymorphisms and Cancer risk: a Meta-analysis Based on 33 Case-control Studies

Xu, Jia-Li,Yin, Zhi-Qiang,Huang, Ming-De,Wang, Xie-Feng,Gao, Wen,Liu, Ling-Xiang,Wang, Rong-Sheng,Huang, Pu-Wen,Yin, Yong-Mei,Liu, Ping,Shu, Yong-Qian Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Objective: Cumulative evidence suggests that MLH1, the key component in the mismatch pathway, plays an important role in human cancers. Two potential functional polymorphisms (-93G>A and I219V) of MLH1 have been implicated in cancer risk. The aim of this meta-analysis was to summarize the evidence for associations. Methods: Eligible studies were identified by searching the electronic literature PubMed, ScienceDirect and Embase databases for relevant reports and bibliographies. Studies were included if of case-control design investigating MLH1 polymorphisms (-93G>A and I219V) and cancer risk with sufficient raw data for analysis. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to evaluate the strength of associations. Results: Our meta-analysis from 33 published case-control studies showed the variant A allele of -93G>A polymorphism to be associated with increased risk in all genetic models (AA vs. GG: OR = 1.22, 95% CI: 1.03-1.44), especially among non-Asians (AA vs. GG: OR = 1.28, 95% CI: 1.04-1.58). For the I219V polymorphism, however, there was no main effect associated with overall cancer risk in any genetic model. Conclusions: The meta-analysis suggested that the MLH1 -93G>A polymorphism may be a biomarker of cancer susceptibility. Large sample association studies and assessment of gene-to-gene as well as gene-to-environment interactions are required to confirm these findings.

Expression and Significance of Microsomal Prostaglandin Synthase-1 (mPGES-1) and Beclin-1 in the Development of Prostate Cancer

Xu, Lu-Wei,Qian, Ming,Jia, Rui-Peng,Xu, Zheng,Wu, Jian-Ping,Li, Wen-Cheng,Huang, Wen-Bin,Chen, Xing-Guo Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

The aim of this study was to investigate the expression and significance of microsomal prostaglandin synthase-1 (mPGES-1) and Beclin-1 in the development of prostate cancer (PCa). Immunohistochemistry was performed on paraffin-embedded sections with rabbit polyclonal against mPGES-1 and Beclin-1 in 40 PCa, 40 benign prostatic hyperplasia (BPH) and 10 normal prostate specimens for this purpose. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for mRNA expression of mPGES-1 and Beclin-1, while MTT assays were used to ascertain the best working concentration of the mPGES-1 inhibitor (CAY10526). The effect of CAY10526 treatment on expression of Beclin-1 in DU-145 cells was studied using Western blot analysis. Localization of Beclin-1 and mPGES-1 was in endochylema. Significant differences in expression was noted among PCa, BPH and normal issues (P<0.05). Beclin-1 expression inversely correlated with mPGES-1 expression in PCa tissue (P<0.05). CAY10526 could significantly block mPGES-1 expression and the proliferation of DU-145 cells (P<0.05), while increasing Beclin-1 levels (P<0.05). Overexpression of mPGES-1 could decrease the autophagic PCa cell death. Inhibiting the expression of mPGES-1 may lead to DU-145 cell death and up-regulation of Beclin-1. The results suggest that inhibition of mPGES-1 may have therapeutic potential for PCa in the future.

Profiles of Bacillus spp. Isolated from the Rhizosphere of Suaeda glauca and Their Potential to Promote Plant Growth and Suppress Fungal Phytopathogens

( Ping Lu ),( Ke Jiang ),( Ya-qiao Hao ),( Wan-ying Chu ),( Yu-dong Xu ),( Jia-yao Yang ),( Jia-le Chen ),( Guo-hong Zeng ),( Zhou-hang Gu ),( Hong-xin Zhao ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.9

Members of the genus Bacillus are known to play an important role in promoting plant growth and protecting plants against phytopathogenic microorganisms. In this study, 21 isolates of Bacillus spp. were obtained from the root micro-ecosystem of Suaeda glauca. Analysis of the 16S rRNA genes indicated that the isolates belong to the species Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus subtilis, Bacillus pumilus, Bacillus aryabhattai and Brevibacterium frigoritolerans. One of the interesting findings of this study is that the four strains B1, B5, B16 and B21 are dominant in rhizosphere soil. Based on gyrA, gyrB, and rpoB gene analyses, B1, B5, and B21 were identified as B. amyloliquefaciens and B16 was identified as B. velezensis. Estimation of antifungal activity showed that the isolate B1 had a significant inhibitory effect on Fusarium verticillioides, B5 and B16 on Colletotrichum capsici (syd.) Butl, and B21 on Rhizoctonia cerealis van der Hoeven. The four strains grew well in medium with 1-10% NaCl, a pH value of 5-8, and promoted the growth of Arabidopsis thaliana. Our results indicate that these strains may be promising agents for the biocontrol and promotion of plant growth and further study of the relevant bacteria will provide a useful reference for the development of microbial resources.

Evolution of Microstructures and Properties in AlxCrFeMn0.8Ni2.1 HEAs

Xu Chen,Di Gao,Jia Xuan Hu,Ye Liu,Chang Ping Tang 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

The microstructures, compression and corrosion behaviors of the as-cast AlxCrFeMn0.8Ni2.1high-entropy alloys (0 ≤ x ≤ 2.3)were investigated in this paper. It was found that the crystal structure changed from initial dual FCC structure to mixed FCCand BCC structure, then to BCC structure as the increasing of Al content. Al0.8CrFeMn0.8Ni2.1alloy exhibited a typicalspinodal structure consisting of alternating two phases microstructure. Moreover, sunflower-like microstructure was obtainedin the as-cast AlxCrFeMn0.8Ni2.1alloys (1.0 ≤ x ≤ 2.0). With the increasing of Al, the macrohardness increased while the plasticitydecreased in the alloys. The addition of an appropriate amount of Al could improve the compressive fracture strengthof the alloys. In addition, the corrosion resistance deteriorated slightly with the increasing of Al in 1 mol/L NaCl solution.

Nonlinear resonances of nonlocal strain gradient nanoplates made of functionally graded materials considering geometric imperfection

Jia-Qin Xu,Gui-Lin She,Yin-Ping Li,Lei-Lei Gan 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.6

When studying the resonance problem of nanoplates, the existing papers do not consider the influences of geometric nonlinearity and initial geometric imperfection, so this paper is to fill this gap. In this paper, based on the nonlocal strain gradient theory (NSGT), the nonlinear resonances of functionally graded (FG) nanoplates with initial geometric imperfection under different boundary conditions are established. In order to consider the small size effect of plates, nonlocal parameters and strain gradient parameters are introduced to expand the assumptions of the first-order shear deformation theory. Subsequently, the equations of motion are derived using the Euler-Lagrange principle and solved with the help of perturbation method. In addition, the effects of initial geometrical imperfection, functionally graded index, strain gradient parameter, nonlocal parameter and porosity on the nonlinear forced vibration behavior of nanoplates under different boundary conditions are discussed.

Two new species of Pustula (Albuginales, Oomycota) from Junggar Basin in China based on morphology and molecular data

Xu, Biao,Choi, Young Joon,Song, Jia Ge,Zhang, Shan He,Xi, Ping Gen,Shin, Hyeon Dong,De Jiang, Zi Springer-Verlag 2018 MYCOLOGICAL PROGRESS Vol.17 No.4

Detection of Powdery Mildew of Bitter Gourd Based on NIR/Fluorescence Spectra

Gao Jia Yu,Wei Dong Zheng,Wang Xiang,Tang Jin Cheng,Xu Ji Tong,Zhao Ping,Ning Xiao Feng 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.3

Purpose Powdery mildew as one of the common vegetable diseases has very rapid infection. Its outbreak will bring about disastrous consequences to vegetable output; thus, it is of key importance to do rapid identifi cation and prevention of powdery mildew. Methods In this test, 100 bitter gourd leaves were collected as research samples, and the data of near-infrared spectra, fl uorescence spectra, and chromatic values L*a*b* , and the classic K-S algorithm was adopted to divide the sample sets; then, the quantitative forecasting and qualitative discrimination models were established. First, Pearson’s correlation analysis was carried out to fi nd the feasibility of taking a * as the modeling parameter, through cross-validation; the quantitative forecasting model was optimized by the PLSR (partial least squares regression) method. The model is also optimized by extracting the spectral feature bands using the continuous projection SPA method. Results The optimization results showed that the MSC + SPA + PLSR quantitative forecasting model of near-infrared spectra could eff ectively improve model precision, which was signifi cantly higher than that of fl uorescence spectra. Classifi cation Leaner was used to establish the quantitative forecasting model. Compared with the model of near-infrared spectra, the SPA + SVM qualitative discrimination model of fl uorescence spectra could improve the identifi cation precision of powdery mildew of bitter gourd as high as 98% through training. Conclusion This study proposed diff erent combination methods based on quantitative forecasting and qualitative discrimination and could provide a method and reference to the identifi cation of powdery mildew of bitter gourd.

A High Power Density and Efficiency Bi-Directional DC/DC Converter for Electric Vehicles

Xiaoyu Jia,Dehong Xu,Shuailin Du,Changsheng Hu,Min Chen,Ping Lin 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In electric vehicle systems, bi-directional DC/DC converters are used to interface the battery bank with the high voltage DC bus of the inverter. The high power density and high efficiency are required for bidirectional DC/DC converters. This paper discusses the relationship between switching frequency, inductor value and passive components volume. First, the topologies of the system and the converter are presented. Then, the loss breakdown model is provided. A selection for the switching frequency is presented and an option of inductor value is provided to reduce the converter size and to keep the converter efficient. Then the converter layout which further enhances the power density is discussed. Finally, a high power density and high efficiency converter prototype is built, and the efficiency and thermal performance evaluation of the converter at different operating conditions is given.