Ag-W18O49-GO Nanocomposite as Highly Effective Antibacterial Agent with Capturing-Killing Mechanism

Le Xu,Linge Chai,Zhao Li,Xiaokun Jin,Danxia Gu,Xueting Chang,Shibin Sun 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.12

In this work, a novel nanocomposite (NC) based on the decoration of Ag nanoparticles (NPs) and W18O49 nanorods (NRs) on the GO surfaces was prepared using combined techniques of solvothermal method and photochemical process. Compared with the Ag-GO NC, the Ag-W18O49-GO NC exhibited enhanced long-term antibacterial activity against the bacterium of Bacillus sp.1NLA3E (Bacillus sp.). The antibacterial mechanisms of both the Ag-GO and Ag-W18O49-GO NCs were distinctly revealed by observation of the direct interaction between the Ag NPs,W18O49 NRs, or GO sheets and the bacterial cells. Results showed that the GO sheets in the NCs mainly acted as supports for trapping or wrapping the bacterial cells, and it was the Ag NPs or W18O49 NRs grown on the GO surfaces that caused direct damage to the cells. The synergistic effects between the Ag NPs or W18O49 NRs and the GO sheets resulted in the prominent long-term antibacterial effect of the Ag-W18O49-GO NC. This work provides in-depth understanding of the mechanism regarding the antibacterial activity of the GO-based NCs.

Optimization Design for Dynamic Characters of Electromagnetic Apparatus Based on Niche Sorting Multi-objective Particle Swarm Algorithm

Le Xu,Jiaxin You,Haidan Yu,Huimin Liang 한국자기학회 2016 Journal of Magnetics Vol.21 No.4

The electromagnetic apparatus plays an important role in high power electrical systems. It is of great importance to provide an effective approach for the optimization of the high power electromagnetic apparatus. However, premature convergence and few Pareto solution set of the optimization for electromagnetic apparatus always happen. This paper proposed a modified multi-objective particle swarm optimization algorithm based on the niche sorting strategy. Applying to the modified algorithm, this paper guarantee the better Pareto optimal front with an enhanced distribution. Aiming at shortcomings in the closing bounce and slow breaking velocity of electromagnetic apparatus, the multi-objective optimization model was established on the basis of the traditional optimization. Besides, by means of the improved multi-objective particle swarm optimization algorithm, this paper processed the model and obtained a series of optimized parameters (decision variables). Compared with other different classical algorithms, the modified algorithm has a satisfactory performance in the multi-objective optimization problems in the electromagnetic apparatus.

재택 양로 모델에 따른 노인의 약물 사용 안전 실태 조사 및 대책

Xu Le,Pan Younghwan 한국서비스디자인학회 2021 한국서비스디자인학회 학술대회자료집 Vol.2021 No.-

Voltage balance evaluation strategy for DC-port faults in centralized aircraft ground power unit based on three-level neutral point clamped cascaded converter

Peng, Xu,Yu, Le,Gong, Kaiyue,Liu, Xiaohan,Yang, Guolong,Xu, Jiangjun,Zhou, Chao,Gao, Lixia,Zhu, Xinyu The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.8

An aircraft ground power unit (GPU) can replace the auxiliary power unit (APU) in an aircraft while the aircraft is parked at an airport. Therefore, the problems associated with the oil consumption and air pollution of the APU are solved. However, the GPU is faced with challenges in terms of utilization, power quality, and fault tolerance. Thus, a novel centralized aircraft GPU based on a three-level neutral point clamped cascaded converter (3LNPC-CC) is introduced in this paper to improve utilization and power quality. Furthermore, an evaluation voltage balance strategy is proposed for the DC-port fault tolerance of the 3LNPC-CC. In addition, both the modulation of the phase shift pulse width modulation (PSPWM) and the control of the double closed loop are used in the 3LNPC-CC. A simulation platform including the control, modulation, and fault tolerance of the system is established to verify the feasibility and performance of the proposed GPU. In particular, it is used to evaluate the voltage balance strategy for DC-port faults. Moreover, a prototype of the GPU and relevant experiments are completed to verify the correctness and feasibility of the system and the strategy.

CDH17 nanobodies facilitate rapid imaging of gastric cancer and efficient delivery of immunotoxin

Jingbo Ma,Xiaolong Xu,Chunjin Fu,Peng Xia,Ming Tian,Liuhai Zheng,Kun Chen,Xiaolian Liu,Yilei Li,Le Yu,Qinchang Zhu,Yangyang Yu,Rongrong Fan,Haibo Jiang,Zhifen Li,Chuanbin Yang,Chengchao Xu,Ying Long,J 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: It is highly desirable to develop new therapeutic strategies for gastric cancer given the low survival rate despite improvement in the past decades. Cadherin 17 (CDH17) is a membrane protein highly expressed in cancers of digestive system. Nanobody represents a novel antibody format for cancer targeted imaging and drug delivery. Nanobody targeting CHD17 as an imaging probe and a delivery vehicle of toxin remains to be explored for its theragnostic potential in gastric cancer. Methods: Naïve nanobody phage library was screened against CDH17 Domain 1-3 and identified nanobodies were extensively characterized with various assays. Nanobodies labeled with imaging probe were tested in vitro and in vivo for gastric cancer detection. A CDH17 Nanobody fused with toxin PE38 was evaluated for gastric cancer inhibition in vitro and in vivo. Results: Two nanobodies (A1 and E8) against human CDH17 with high affinity and high specificity were successfully obtained. These nanobodies could specifically bind to CDH17 protein and CDH17-positive gastric cancer cells. E8 nanobody as a lead was extensively determined for tumor imaging and drug delivery. It could efficiently co-localize with CDH17-positive gastric cancer cells in zebrafish embryos and rapidly visualize the tumor mass in mice within 3 h when conjugated with imaging dyes. E8 nanobody fused with toxin PE38 showed excellent anti-tumor effect and remarkably improved the mice survival in cell-derived (CDX) and patient-derived xenograft (PDX) models. The immunotoxin also enhanced the anti-tumor effect of clinical drug 5-Fluorouracil. Conclusions: The study presents a novel imaging and drug delivery strategy by targeting CDH17. CDH17 nanobodybased immunotoxin is potentially a promising therapeutic modality for clinical translation against gastric cancer.

A rational design of AIE-active fluorophore for the fingerprintoptical detection

Le Yu,Xu Yunjie,김정련,이지은,김종승 대한화학회 2023 Bulletin of the Korean Chemical Society Vol.44 No.6

Fingerprints are one of the distinguishing characteristics of an individual,remaining unaltered throughout one’s lifetime. It should be noted that finger-prints are significant and reliable evidence in various cases, such as criminalinvestigations, medical diagnosis, and public security. Thus, it is necessary todevelop efficient techniques for fingerprints detection. Fortunately, the fluores-cence emission of aggregation-induced emission (AIE) materials would increaseinstead of quenching upon excitation when they label fingerprints, whichwould clearly observe the structure of fingerprints. Herein, we devised a novelAIE-active fluorophore (NI-DB) with electron donor-πbridge-electron acceptor(D-π-A) structure based on the 1,8-naphthalimide. To our delight, after finger-prints fixed by cyanoacrylate glue fuming,NI-DBis capable of detecting andimaging fingerprints via its intrinsic fluorescence emission. And, with the aid ofthis technique, fingerprints on various object surfaces are successfully devel-oped, suggesting the broad applicability.

Structural Evaluation of Torsional Rigidity of New FRP–Aluminum Space Truss Bridge with Rigid Transverse Braces

Le Zhu,Dongdong Zhang,Fei Shao,Qian Xu,Qilin Zhao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

A unique fiber-reinforced polymer (FRP)–aluminum spatial truss structure with upper I-type, transverse beam braces was developed for deployable bridging, yielding the operational advantages of bestraddled erection bridges. Experimental testing and numerical simulation were performed to evaluate the torsional rigidity of a fabricated cantilever, full-scale experimental structure. The predictions obtained based on a computational finite element model were strongly consistent with the experimental results. Moreover, a numerical decomposition and reconstruction procedure was employed to understand the load-bearing mechanism of the structure. The results demonstrated that the improved transverse braces possessed adequate capacity for providing sufficient rigidity and lateral stability to the complete twin-treadway structure under torsion. The torsional center of the improved structure was located at the axis of symmetry of the twin-treadway bridge deck. The representative torsional rigidity of the twin-treadway module was approximately 87.5 kN·m2/degree. Compared to the original construction, the improved structure exhibited only minor discrepancies regarding the torsional rigidity, and consistent characteristics in terms of the load-bearing mechanism. The torsional rigidity of the improved twin-treadway structure was primarily generated by the vertical bending rigidities of its two parallel single treadways through the rigid transverse braces. This significant finding specifically pertains to the unique twin-treadway hybrid bridge. The results presented in this work are expected to provide valuable insights, which could, in turn, lead to further the development of similar lightweight structural systems.

Yaw wind effect on flutter instability of four typical bridge decks

Le-Dong Zhu,You-Lin Xu,Zhenshan Guo,Guang-Zhao Chang,Xiao Tan 한국풍공학회 2013 한국풍공학회지 Vol.17 No.3

When evaluating flutter instability, it is often assumed that incident wind is normal to the longitudinal axis of a bridge and the flutter critical wind speed estimated from this direction is most unfavorable. However, the results obtained in this study via oblique sectional model tests of four typical types of bridge decks show that the lowest flutter critical wind speeds often occur in the yaw wind cases. The four types of bridge decks tested include a flat single-box deck, a flat π-shaped thin-wall deck, a flat twin side-girder deck, and a truss-stiffened deck with and without a narrow central gap. The yaw wind effect could reduce the critical wind speed by about 6%, 2%, 8%, 7%, respectively, for the above four types of decks within a wind inclination angle range between -3° and 3°, and the yaw wind angles corresponding to the minimal critical wind speeds are between 4° and 15°. It was also found that the flutter critical wind speed varies in an undulate manner with the increase of yaw angle, and the variation pattern is largely dependent on both deck shape and wind inclination angle. Therefore, the cosine rule based on the mean wind decomposition is generally inapplicable to the estimation of flutter critical wind speed of long-span bridges under skew winds. The unfavorable effect of yaw wind on the flutter instability of long-span bridges should be taken into consideration seriously in the future practice, especially for supper-long span bridges in strong wind regions.

Tim-3 Expression by Peripheral Natural Killer Cells and Natural Killer T Cells Increases in Patients with Lung Cancer - Reduction after Surgical Resection

Xu, Li-Yun,Chen, Dong-Dong,He, Jian-Ying,Lu, Chang-Chang,Liu, Xiao-Guang,Le, Han-Bo,Wang, Chao-Ye,Zhang, Yong-Kui Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Background: The purpose of this study was to investigate Tim-3 expression on peripheral CD3-CD56+ natural killer (NK) cells and CD3+CD56+ natural killer T (NKT) cells in lung cancer patients. Materials and Methods: We analyzed Tim-3+CD3-CD56+ cells, Tim-3+CD3-$CD56^{dim}$ cells, Tim-3+CD3-$CD56^{bright}$ cells, and Tim-3+CD3+CD56+ cells in fresh peripheral blood from 79 lung cancer cases preoperatively and 53 healthy controls by flow cytometry. Postoperative blood samples were also analyzed from 21 members of the lung cancer patient cohort. Results: It was showed that expression of Tim-3 was significantly increased on CD3-CD56+ cells, CD3-$CD56^{dim}$ cells and CD3+CD56+ cells in lung cancer patients as compared to healthy controls (p=0.03, p=0.03 and p=0.04, respectively). When analyzing Tim-3 expression with cancer progression, results revealed more elevated Tim-3 expression in CD3-CD56+ cells, CD3-$CD56^{dim}$ cells and CD3+CD56+ cells in cases with advanced stages (III/IV) than those with stage I and II (p=0.02, p=0.04 and p=0.01, respectively). In addition, Tim-3 expression was significantly reduced on after surgical resection of the primary tumor (p<0.01). Conclusions: Tim-3 expression in natural killer cells from fresh peripheral blood may provide a useful indicator of disease progression of lung cancer. Furthermore, it was indicated that Tim-3 might be as a therapeutic target.

Dynamic analysis of wind-vehicle-bridge system considering additional moments of non-uniform winds by wind shielding effect of multi-limb tower

Xu Han,Huoyue Xiang,Xuli Chen,Yong-Le Li 한국풍공학회 2023 Wind and Structures, An International Journal (WAS Vol.36 No.1

To evaluate the wind shielding effect of bridge towers with multiple limbs on high-speed trains, a wind tunnel test was conducted to investigate the aerodynamic characteristics of vehicles traversing multi-limb towers, which represented a combination of the steady aerodynamic coefficient of the vehicle-bridge system and wind environment around the tower. Subsequently, the analysis model of wind-vehicle-bridge (WVB) system considering the additional moments caused by lift and drag forces under nonuniform wind was proposed, and the reliability and accuracy of the proposed model of WVB system were verified using another model. Finally, the factors influencing the wind shielding effect of multi-limb towers were analyzed. The results indicate that the wind speed distributions along the span exhibit two sudden changes, and the wind speed generally decreases with increasing wind direction angle. The pitching and yawing accelerations of vehicles under nonuniform wind loads significantly increase due to the additional pitching and yawing moments. The sudden change values of the lateral and yawing accelerations caused by the wind shielding effect of multi-limb tower are 0.43 m/s2 and 0.11 rad/s2 within 0.4 s, respectively. The results indicate that the wind shielding effect of a multi-limb tower is the controlling factor in WVB systems.