Molecular Characteristics and Resistant Mechanisms of Imipenem-Resistant Acinetobacter baumannii Isolates in Shenyang, China

Jing Ping Zhang,Wan Zhu,Su Fei Tian,Yun Zhuo Chu,Bai Yi Chen 한국미생물학회 2010 The journal of microbiology Vol.48 No.5

The investigation was carried out to elucidate the molecular characteristics and resistant mechanisms of imipenem-resistant Acinetobacter baumannii. Thirty-seven isolates were collected from January 2007 to December 2007. The homology of the isolates was analyzed by both pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The genes of β-lactamases, adeB, and class 1 integron were polymerase chain reaction amplified. Genotype analysis of the 37 A. baumannii isolates by PFGE revealed the circulation of four PFGE types (A-D) ; the A- and B-type accounted for 48.6% and 40.5%, respectively. MLST showed the existence of three allelic profiles. The agar dilution method was carried out to determine the MIC of imipenem, in the absence or presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP, 10 μg/ml). The MICs of the strains to imipenem were between 16 μg/ml and 128 μg/ml. When CCCP was added, a MIC decrease of at least four-fold was observed in 20 isolates, which belonged to the A- or C-type. AdeB and blaPER-1 genes were each detected in 35 isolates, blaOXA-23 gene in 34 isolates and blaOXA-58-like gene in 24 isolates. All isolates harbored blaOXA-51-like genes. No isolates carried the blaIMP-1 gene. Integron was detected in 25 isolates, which mediated the resistance to aminoglycosides and rifampin. The epidemiologic data suggested that the increasing infection of A. baumannii in our hospital was mainly caused by the inter-hospital spread of two epidemic clones. The AdeABC efflux system may be the important factor that leads to the high level of imipenem-resistance in PFGE A-type.

Adaptation of Cucurbit Species to Changes in Substrate Temperature: Root Growth, Antioxidants, and Peroxidation

( Yong Ping Zhang ),( Yi Li Zhang ),( Yan Hong Zhou ),( Jing Quan Yu ) 한국식물학회 2007 Journal of Plant Biology Vol.50 No.5

To investigate their response to changes in substrate temperatures, the roots from six species of cucurbit plants were exposed to 14℃, 24℃, or 34℃, while their aerial portions were maintained at natural ambient temperatures (23℃ to 33℃). These species could be classified into three groups based on their stress response: Group A, Cucurbita ficifolia and C. maxima, heatsensitive but cold-tolerant; Group B, Cucumis sativus and C. melo, heat- and cold-sensitive; and Group C, Luffa cylindrica and Benincasa hispida, heat-tolerant but cold-sensitive. The highest growth rates and lowest contents of malondialdehyde (MDA) for plants in Groups A, B, and C were achieved at temperatures of 14℃, 24℃, and 24℃ to 34℃, respectively. Superoxide dismutase (SOD) activity was lowest in the roots exposed to optimal growth temperatures while activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (G-POD) operated coordinately in a complicated manner to prevent the accumulation of reactive oxygen species (ROS) in the root cells. Moreover, all plants, regardless of species, responded to unfavorable temperatures by increasing their synthesis of ascorbate and glutathione as well as by reducing the redox ratio of those two important antioxidants.

Carbon dioxide reforming of methane over MgO promoted Ni/CNT catalyst

Dehua Zhang,Guangcheng Wei,Yiru Wang,Jing Wang,Ping Ning,Qiulin Zhang,Mingzhi Wang,Tengfei Zhang,Kaixian Long 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.10

Carbon dioxide reforming of methane to syngas was investigated over a series of MgO promoted Ni/CNT catalysts. MgO played a critical role in improving the catalytic performance of Ni/CNT. The results showed that the addition of MgO strengthened the interaction of Ni and interior surface of CNT. Highly dispersed nickel particles with small size (less than 4.5nm) were also observed in MgO modified CNT. Otherwise, the NiO nanoparticles were facilely reduced over the catalyst prepared with a narrow size of CNT, as shown in H2-TPR. The reaction tests demonstrated that the Ni-based catalyst with an addition of MgO and narrow size of CNT exhibited better catalytic activity. Furthermore, the lifetime of Ni-based catalyst was prolonged effectively after adding MgO, attributed to the stabilization and dispersion of Ni particles and the effective restraint on the gasification of CNT.

Enhanced Room-Temperature Thermoelectric Performance of In-Doped ZnO:Al Thin Films through Prefabricated Layer Doping Method

Ping Fan,Zhuang-Hao Zheng,Jing-Ting Luo,Guang-Xing Liang,Dong-Ping Zhang 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.3

In this study, AZO thin films prepared by direct current reactive magnetron sputtering using a Zn-Al alloy target and In with varied content were doped through the prefabricated layer doping method in order to optimize their thermoelectric properties. The effects of In content on the room temperature microstructure and thermoelectric properties of the AZO thin films were investigated. It was found that the absolute value of the Seebeck coefficient of the thin films increases stably after In doping and reaches 153 μV·K−1 when the In content is 0.71%. Though the electrical conductivity of In-doped thin films is smaller than those of the un-doped films, the power factor of the thin films shows a significant increase after In doping with a maximum value of 2.22 × 10−4 W·m−1·K−2, which is several times that of the un-doped films.

Effect of Blending Modifications for Phenylethynyl-terminated Polyimides

Ping Yu,Min-zhao Xue,Yan-gang Liu,Xue Yang,Li-jing Pan,Yan-li Zhang,Wei Wang 한국섬유공학회 2020 Fibers and polymers Vol.21 No.2

A reactive diluent (ODA-PEPA) and a flexible phenylethynyl-terminated imide oligomer (PEI-PEPA) were designed and synthesized based on the 2,3,3',4'-diphenyl ether tetracarboxylic acid dianhydride (a-ODPA), 3,4'-oxydianiline(3,4'-ODA), and 4-phenylethynylphthalic anhydride (PEPA). Solution blended systems with the addition of 5, 10, and 15 wt% ODA-PEPA to PEI-PEPA oligomer and their cured resin systems were prepared. Results showed that ODA-PEPA is semi-crystalline in nature. The Tg values of cured resins were improved from 273 oC to 280 oC by the addition of ODA-PEPA, due to the higher crosslink densities. In addition, rheological properties of blends showed lower melt viscosity and wider processing window, revealing improved melt processabilities for potential application in making advanced composites. The isothermal viscosity in 280 oC of PEI-PEPA containing 15 wt% ODA-PEPA reactive diluent decreased by two thirds, due to the low molecular weight of ODA-PEPA. The cured blends demonstrated high thermal stability and heat resistance. 5 wt% thermal decomposition temperatures (Td5) of the cured blends were above 549 oC and 547 oC in N2 and air atmosphere, respectively. The char yield reported at 800 oC in N2 atmosphere increased from 58.8% to 63.7 % with the addition of ODAPEPA. Meanwhile, the cured polyimides blends possessed good bond strength (> 9.3 MPa).

Three-dimensional Fe2O3–TiO2–graphene aerogel nanocomposites with enhanced adsorption and visible light-driven photocatalytic performance in the removal of RhB dyes

Jing-Jie Zhang,Pan Qi,Jie Li,Xiu-Cheng Zheng,Pu Liu,Xin-Xin Guan,Guang-Ping Zheng 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-

A series of Fe2O3 and TiO2 co-doped graphene aerogel (Fe2O3–TiO2–GA) nanocomposites with a unique 3D architecture are assembled by a one-pot hydrothermal method combined with freeze-drying. The one with 30 wt% Fe2O3 exhibits the highest adsorptivity (95.0%) and the another with 25 wt% Fe2O3 displays the highest total efficiency (97.7%) including adsorption and visible light-driven photocatalytic degradation for rhodamine B dyes (20.0 mg L−1, 25 mL) within 1 h over 5.0 mg of the nanocomposites. The materials also display satisfactory cyclic stability and the removal efficiency can be 81.8% even after four runs. Additionally, a related photocatalytic mechanism is proposed.

Efficient and Selective Construction of Pyrrolo[3,2-d]pyrimidine Derivatives

Ping He,Jing Wu,Yang-Gen Hu,Zai-Fang Li,Qiu-Fei Hou,Yan-Ling Wang,Kun Zhao,Erli Zhang 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

An efficient and selective method for the synthesis of ethyl 2-amino/aryloxy-3-aryl-4-oxo-5-phenyl-4,5- dihydro-3H-pyrrolo[3,2-d]pyrimidine-7-carboxylate derivatives has been developed. The main process involved the reaction of diethyl 1-phenyl-3-((triphenylphosphoranylidene)amino)-1H-pyrrole-2,4-dicarboxylate and aromatic isocyanates, followed by addition of amines/phenols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate.

A Bidirectional Three-level DC-DC Converter with a Wide Voltage Conversion Range for Hybrid Energy Source Electric Vehicles

Ping Wang,Chendong Zhao,Yun Zhang,Jing Li,Yongping Gao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

New Evidence for the Involvement of the EGF Receptor Pathway in Hair Follicle Morphogenesis in uncv Mice

Jing Zhang,Xiao Kun Teng,Li Zhen Si,Ping Tong Zhou,Xiang Yin Kong,Lan Dian Hu 한국유전학회 2008 Genes & Genomics Vol.30 No.4

Hair follicle (HF) morphogenesis depends upon a delicate balance between cell proliferation and apoptosis, both of which are known to be controlled by a number of signal pathways. In this study, we utilize the uncv homozygous mouse to investigate the underlying mechanisms giving rise to the relevant phenotypes. In so doing, we have detected changes in the EGFR, Akt and MAPK signaling pathways. Our results show that the expression patterns of active Akt, MAPK and EGFR are altered with regard to localization in the outer root sheath (ORS) of the wild type mouse and in the follicular bulbs of the uncv homozygous mouse. These data suggest that EGFR signaling may play different roles in different cellular locations. Further, ectopic EGFR signaling in the follicular bulbs of the uncv homozygous mouse may lead to catagen (entrance into the apoptosis phase). Moreover, when the EGFR ligand was overexpressed in the uncv heterozygous mouse, aggravation of HF disordered development ensued. Together, these results demonstrate that EGFR participates in a functionally compartmentalized signaling network that controls follicular development homeostasis.

Study on anchorage effect on fractured rock

Jing Wang,Shucai Li,Li-Ping Li,Weishen Zhu,Qian-qing Zhang,Shu-Guang Song 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.6

The effects of anchor on fractured specimens in splitting test are simulated by DDARF method, the results of which are compared with laboratory test results. They agree well with each other. The paper contents also use the laboratory model test. The main research objects are three kinds of specimens, namely intact specimens, jointed specimens and anchored-jointed specimens. The results showed that with the joint angle increased, the weakening effects of jointed rock mass are more obvious. At these points, the rock bolts' strengthening effects on the specimens have become more significant. There is a significant impact on the failure modes of rock mass by the joint and the anchorage.