A Potent Brucella abortus 2308 Δery Live Vaccine Allows for the Differentiation between Natural and Vaccinated Infection

Junbo Zhang,Shuanghong Yin,Fei Guo,Ren Meng,Chuangfu Chen,Hui Zhang,Zhi-qiang Li,Qiang Fu,Huijun Shi,Shengwei Hu,Wei Ni,Tiansen Li,Ke Zhang 한국미생물학회 2014 The journal of microbiology Vol.52 No.8

Brucellosis is a globally distributed zoonotic disease that causes animal and human diseases. However, the current Brucella abortus vaccines (S19 and RB51) are deficient; they can cause abortion in pregnant animals. Moreover, when the vaccine S19 is used, tests cannot differentiate natural from vaccinated infection. Therefore, a safer and more potent vaccine is needed. A Brucella abortus 2308 ery promoter mutant (Δery) was constructed to overcome these drawbacks. The growth of the Δery mutant was significantly attenuated in macrophages and mice and induced high protective immunity in mice. Moreover, Δery induced an anti-Brucellaspecific IgG (immunoglobulin G) response and stimulated the expression of interferon-gamma (INF-γ) and interleukin-4 (IL-4). Furthermore, the expression of EryA antigen allowed for the serological differentiation between natural and vaccinated infection in mice. These results indicate that the Δery mutant is a potential attenuated live vaccine candidate against virulent Brucella abortus 2308 (S2308) infection.

Synergistic effect of novel ionic liquid/graphene complex on the flame retardancy of epoxy nanocomposites

Zhang Chunhong,Xu Zice,Sui Wenbo,Zang Junbo,Ao Yuhui,Wang Lu,Shang Lei 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Epoxy resin (EP) is a thermosetting resin with excellent properties, but its application is limited due to its high brittleness and poor flame retardancy. Therefore, to solve this problem, a dispersion system of imidazole-containing ionic liquid ([Dmim]Es) and graphene in epoxy resin is designed based on the π–π stacking effect between imidazole and graphite layers. The study on the thermal and flame-retardant properties of the composites show that the modified [Dmim]Es–graphene nanosheets improved the flame retardancy, smoke suppression and thermal stability of epoxy resin. With the addition of 5wt% [Dmim]Es and 1% Gra, the exothermic rate (HRR) and total exothermic (THR) of the composites decrease by 35% and 30.2% compared with the untreated epoxy cross-linking, respectively. The limiting oxygen index reaches 33.4%, the UL-94 test rating reaches V-0. The characterization of mechanical properties shows that the tensile properties and impact properties increased by 13% and 30%, respectively. Through SEM observation, the addition of [Dmim]Es improves the dispersion of graphene in the EP collective and changes the mechanical fracture behavior. The results show that ionic liquid [Dmim]Es-modified graphene nanosheets are well dispersed in the matrix, which not only improves the mechanical properties of epoxy resin (EP), but also has a synergistic effect on flame retardancy. This work provides novel flame-retardant and graphene dispersion methods that broaden the range of applications of epoxy resins.

Photo-induced charge separation properties of NiO/Bi2O3 heterojuctions with efficient simulated solar-driven photocatalytic performance

Qi Yang,Junbo Zhong,Jian zhang Li,Jiufu Chen,Zhen Xiang,Tao Wang,Minjiao Li 한국물리학회 2017 Current Applied Physics Vol.17 No.4

The inherent drawbacks of Bi2O3 greatly limit the practical application of Bi2O3, thus it is crucial to boost the photocatalytic activity of Bi2O3, and therefore NiO was employed to couple with Bi2O3. In this paper, NiO/Bi2O3 heterostructures with improved sunlight driven -photocatalytic activity were constructed by a pore impregnating method. The samples were studied by Brunauer -Emmett- Teller (BET) method, X-ray diffraction (XRD), UVeVis diffuse reflectance spectroscopy (DRS), high-resolution transmission electron microscopy (HRTEM), surface photovoltage (SPV) spectroscopy and electron spin-resonance (ESR) spectroscopy. The photocatalytic activities of NiO/Bi2O3 heterostructures toward discoloration of methyl orange (MO) aqueous solutions were evaluated. The results display that the presence of NiO in the heterojuctions increases the specific surface area, the absorbance in the visible light region, the separation rate of the photo-induced charge pairs and the formation of $O2 in the photocatalytic system.

Promoting N2 electroreduction to ammonia by fluorine-terminating Ti3C2Tx MXene

Ding Yu,Zhang Junbo,Guan Anxiang,Wang Qihao,Li Si,Al-Enizi Abdullah M.,Qian Linping,Zhang Lijuan,Zheng Gengfeng 나노기술연구협의회 2021 Nano Convergence Vol.8 No.14

Two-dimensional MXene-based materials are potential of presenting unique catalytic performances of electrocatalytic reactions. The surface functionalization of MXene-based catalysts is attractive for developing efficient electrocatalysts toward nitrogen reduction reaction. Herein, we reported a Ti 3 C 2 T x MXene with a medium density of surface functionalized fluorine terminal groups, as an excellent N 2 reduction reaction electrocatalyst with enhanced adsorption and activation of N 2 . The Ti 3 C 2 T x MXene catalyst showed a production rate of ammonia as 2.81 × 10 –5 μmol·s −1 ·cm −2 , corresponding to a partial current density of 18.3 μA·cm −2 and a Faradic efficiency of 7.4% at − 0.7 V versus reversible hydrogen electrode in aqueous solutions at ambient conditions, substantially exceeding similar Ti 3 C 2 T x MXene catalysts but with higher or lower densities of surface fluorine terminal groups. Our work suggests the capability of developing surface functionalization toolkit for enhancing electrochemical catalytic activities of two-dimensional MXene-based materials.

Role of methylenetetrahydrofolate reductase 677C?T polymorphism in the development of myocardial infarction: evidence from an original study and updated meta-analysis

Yi Luan,Wenbin Zhang,Min Wang,Pei Zhang,Zhimin Xue,Guosheng Fu,Junbo Ge 한국유전학회 2016 Genes & Genomics Vol.38 No.9

The methylenetetrahydrofolate reductase (MTH FR) gene variant 677C?T is considered a risk factor for myocardial infarction (MI) in Caucasians, but it remains unclear whether this applies to Chinese or other Asian populations. A total of 551 controls and 304 age-matched Chinese MI patients were recruited. MTHFR genotypes were determined. A subsequent meta-analysis was performed to determine the association between MTHFR and MI in Asia. Conventional risk factors such as hypertension, diabetes mellitus and low-density lipoprotein exhibited no significant differences between the two groups. Genotype frequencies among cases and controls were compatible with Hardy– Weinberg equilibrium. The frequencies of CC, CT and TT genotypes were 28, 46 and 26 % for patients with MI and 31, 52 and 17 % for the matched control group (p = 0.006). T-allele frequency in MI patients was higher than in controls (49 vs. 43 %, odds ratio = 0.785, 95 % confidence interval = 0.644–0.958, p = 0.017). A total of 16 studies including ours were identified, involving 4053 patients and 6791 controls. A recessive genotype model of MTHFR 677C?T polymorphism, but not a dominant genotypemodel, was significantly associated with greater MIrisk in Asians. MI risk increased 48, 37 and 47 % for the TT homozygote compared with the CC wild type, CT heterozygote and the combination of CT and CC. Thus, we conclude that the MTHFR gene variant 677C?T is a risk factor for MI in the Chinese population and the TT genotype is associated with a significant increase in MI risk in Asia.

A LysM Domain-Containing Protein LtLysM1 Is Important for Vegetative Growth and Pathogenesis in Woody Plant Pathogen Lasiodiplodia theobromae

Dulanjalee Lakmali Harishchandra,Wei Zhang,Xinghong Li,Kandawatte Wedaralalage Thilini Chethana,Kevin David Hyde,Siraprapa Brooks,Jiye Yan,Junbo Peng 한국식물병리학회 2020 Plant Pathology Journal Vol.36 No.4

Lysin motif (LysM) proteins are reported to be necessary for the virulence and immune response suppression in many herbaceous plant pathogens, while far less is documented in woody plant pathogens. In this study, we preliminarily characterized the molecular function of a LysM protein LtLysM1 in woody plant pathogen Lasiodiplodia theobromae. Transcriptional profiles revealed that LtLysM1 is highly expressed at infectious stages, especially at 36 and 48 hours post inoculation. Amino acid sequence analyses revealed that LtLysM1 was a putative glycoprotein with 10 predicted N-glyco- sylation sites and one LysM domain. Pathogenicity tests showed that overexpressed transformants of LtLysM1 displayed increased virulence on grapevine shoots in comparison with that of wild type CSS-01s, and RNAi transformants of LtLysM1 exhibited significantly de- creased lesion length when compared with that of wild type CSS-01s. Moreover, LtLysM1 was confirmed to be a secreted protein by a yeast signal peptide trap as- say. Transient expression in Nicotiana benthamiana together with protein immunoblotting confirmed that LtLysM1 was an N-glycosylated protein. In contrast to previously reported LysM protein Slp1 and OsCEBiP, LtLysM1 molecule did not interact with itself based on yeast two hybrid and co-immunoprecipitation assays. These results indicate that LtLysM1 is a secreted protein and functions as a critical virulence factor during the disease symptom development in woody plants.

Microstructures and Mechanical Properties of Equiatomic NiTi Shape Memory Alloy Undergoing Local Canning Compression and Subsequent Annealing

Dong Sun,Shuyong Jiang,Xiaodong Xing,Bingyao Yan,Junbo Yu,Yanqiu Zhang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

Local canning compression is imposed on equiatomic NiTi shape memory alloy (SMA) with complete B19′ martensite. Afraction of retained nanocrytalline grains are embedded in the dominant amorphous phase. The compressed NiTi samples areannealed for 2 h at various temperatures, including 300, 450 and 600 °C. Grain size increases with increasing crystallizationtemperature during heat treatment. Under annealing at 300 °C, nanocrystalline grains are dominant in NiTi SMA, where thereexists local amorphous zone. Under annealing at 450 °C, almost complete nanocrystalline can be obtained. Under annealingat 600 °C, grain size increases substantially, but there still exists a small amount of nanocrystalline grains. Under annealingat 300 °C, NiTi SMA exhibits extremely high elastic limit, but its plasticity is poor. Under annealing at 450 °C, NiTi SMAexhibits very high yield stress and it simultaneously keeps high plasticity. Under annealing at 600 °C, NiTi SMA exhibitsrelatively low yield stress, but its yield stress is still higher than that of as-received NiTi SMA and its plasticity is also high.

Polarization Maintaining Dichroic Beam-splitter and Its Surface Shape Control by Back Side AR Coating

Chong Ma,Gang Chen,Dingquan Liu,Rong-Jun Zhang,Junbo He,Xudan Zhu,Daqi Li 한국광학회 2021 Current Optics and Photonics Vol.5 No.5

Dichroic beam-splitter (DBS) with polarization-maintaining took an important role in the free space quantum telecommunication tests on the Micius satellite of China. In this presentation, we designed and prepared a 50 layer polarization-maintaining DBS coating by a dual ion beam sputtering deposition (Dual-IBS) method. In order to solve a stress problem, an 18 layer special anti-reflection (AR) coating with similar physical thickness ratio was deposited on the backside. By stress compensation, the surface flatness RMS value of the DBS sample decreased from 0.341 λ (@632.8 nm) to 0.103 λ while beam splitting and polarization maintaining properties were almost kept unchanged. Further, we discussed the mechanism of film stress and stress compensation by equation deduction and found that total stress had a strong relationship with the total physical thickness and the ratio of layer materials.

Association of Quantitative Flow Ratio with Lesion Severity and Its Ability to Discriminate Myocardial Ischemia

Neng Dai,Doyeon Hwang,Joo Myung Lee,Jinlong Zhang,Yaliang Tong,Ki-Hyun Jeon,Jin Chul Paeng,Gi Jeong Cheon,Bon-Kwon Koo,Junbo Ge 대한심장학회 2021 Korean Circulation Journal Vol.51 No.2

Background and Objectives: Quantitative flow ratio (QFR) is an angiography-based technique for functional assessment of coronary artery stenosis. This study investigated the response of QFR to different degree of stenosis severity and its ability to predict the positron emission tomography (PET)-defined myocardial ischemia. Methods: From 109 patients with 185 vessels who underwent both 13N-ammonia PET and invasive physiological measurement, we compared QFR, fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) for the responses to the different degree of anatomical (percent diameter stenosis [%DS]) and hemodynamic (relative flow reserve [RFR], coronary flow reserve, hyperemic stenosis resistance, and stress myocardial flow) stenosis severity and diagnostic performance against PET-derived parameters. Results: QFR, FFR, and iFR showed similar responses to both anatomic and hemodynamic stenosis severity. Regarding RFR, the diagnostic accuracy of QFR was lower than FFR (76.2% vs. 83.2%, p=0.021) and iFR (76.2% vs. 84.3%, p=0.031). For coronary flow capacity (CFC), QFR showed a lower accuracy than iFR (74.1% vs. 82%, p=0.031) and lower discriminant function than FFR (area under curve: 0.74 vs. 0.79, p=0.044). Discordance between QFR and FFR or iFR was shown in 14.6% of cases and was driven by the difference in %DS and heterogeneous distribution of PET-derived RFR and stress myocardial blood flow. Conclusions: QFR demonstrated a similar response to different anatomic and hemodynamic stenosis severity as FFR or iFR. However, its diagnostic performance was inferior to FFR and iFR when PET-derived RFR and CFC were used as a reference.

Investigation of the Deformation Characteristics and Bearing Capacity of a Segment Structure of a Shield Tunnel with Cracks

Chuankun Liu,Shimin Wang,Wenqi Guo,Fan Chen,Junbo Zhang,Chuan He 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.1

In this paper, the displacement data of a segment lining structure in a similar model test were analyzed in depth based on a field investigation and the analysis of a cracked segment in a metro project. In doing so, we proved the displacement characteristics and bearing capacity of shield tunnel segments with different cracks numbers, lengths, and locations. The results showed that the presence of a crack decreases the overall stiffness of the structure relative to an undamaged segment ring and causes the deformation increases with the same load to increase. One-third of the width of a segment is the demarcation point at which the length of the crack begins to affect the mechanical properties of structure of the lining of the segment. When the length of the crack is larger than one-third the width of the segment, the instability of the structure tends to result in sudden failure. Although an increase in the number of cracks does not reduces the ultimate bearing capacity of the structure further, the deformation of the structure of the lining of the segment increases significantly as the number of cracks increases. compared to a crack at the vault and at the arch waist, the ultimate bearing capacity of the segment is the same when the crack is at the bottom of the arch, but the effects of cracks located at the arch bottom in the structural deformation are the most significant.