Nonlinear analysis of cable-stayed spatial latticed structures

Zhou, Dai,Liu, Hongyu,Jin, Bo Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.15 No.4

The combination of spatial latticed structures (hereafter SLS) and flexible cables, the cable-stayed spatial latticed structures (hereafter CSLS) can cross longer span. According to variation principle, a novel geometric nonlinear formulation for 3-D bar elements considering large displacement and infinitesimal rotation increments with second-order precision is developed. The cable nonlinearity is investigated and it is taken that the secant modulus method can be considered as an exact method for a cable member. The tower column with which the cables link is regarded as a special kind of beam element, and, a new simplified stiffness formulation is presented. The computational strategies for the nonlinear dynamic response of structures are given, and the ultimate load carrying capacities and seismic responses are analyzed numerically. It is noted that, compared with corresponding spatial latticed shells, the cable-stayed spatial latticed shells have more strength and more stiffness, and that the verical seismic responses of both CSLS and CLS are remarkably greater than the horizontal ones. In addition, the computation shows that the stiffness of tower column influences the performance of CSLS to a certain extent and the improvement of structural strength and stiffness of CSLS is relevant not only to cables but also to tower columns.

Development of a stable and efficient zein based nanopesticides through green and simple way for improving utilization efficiency

Dai Xiuchun,Chen Long,Zhou Hongjun,Zhou Xinhua 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

Nanopesticides represent one of the effective ways of reducing the use of pesticides and the environmental pollution. Natural zein as a potential carrier for nanoencapsulation of pesticides has the disadvantages of large amount of organic solvents and poor dispersibility. In this study, a water soluble of zein peptides was obtained by hydrolyzed under alkaline conditions with heated and stability of nanopesticides were prepared through crosslinked after self-assemble. As the results, the zein peptides spontaneously assembled into spherical particles in an aqueous solution, the nanopesticides (avermectin, AVM), with uniform size distribution and size can be adjusted by the glutaraldehyde, have a great stability, and redispersed in water after freeze-drying. Moreover, nanoencapsulation protects avermectin from UV light, with 24% of the encapsulated AVM remaining intact after exposure to UV for 60 min, compared to less than 6% for the bare AVM. In addition, the nanoformulation had similar insecticidal activity to commercial EC and the cross-linking of particles slowed down the release rate and the curves were consistent with Higuchi model different from the abnormal diffusion in the uncross linked state. In short, this study provides a simple method to obtain stabilizable nanopesticides based on natural polymer on a green way.

Potential Therapeutic Efficacy of Curcumin in Liver Cancer

Dai, Xin-Zheng,Yin, Hai-Tao,Sun, Ling-Fei,Hu, Xiang,Zhou, Chong,Zhou, Yun,Zhang, Wei,Huang, Xin-En,Li, Xiang-Cheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Purpose: Liver cancer, one of the most common cancers in China, is reported to feature relatively high morbidity and mortality. Curcumin (Cum) is considered as a drug possessing anti-angiogenic, anti-inflammation and anti-oxidation effect. Previous research has demonstrated antitumor effects in a series of cancers. Materials and Methods: In this study the in vitro cytotoxicity of Cum was measured by MTT assay and pro-apoptotic effects were assessed by DAPI staining and measurement of caspase-3 activity. In vivo anti-hepatoma efficacy of Cum was assessed with HepG2 xenografts. Results: It is found that Cum dose-dependently inhibited cell growth in HepG2 cells with activation of apoptosis. Moreover, Cum delayed the growth of liver cancer in a dose-dependent manner in nude mice. Conclusions: Cum might be a promising phytomedicine in cancer therapy and further efforts are needed to explore this therapeutic strategy.

Effect of Thermal Aging on Threshold Field Strength and Relative Permittivity of Cross-Linked Polyethylene with Different Cross-Linking Agent Contents

Wan Dai,Qi Fei,Zhou Quan,Zhou Hengyi,Zhao Miao,Duan Xujin 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.6

This article presents the eff ect of thermal aging on threshold fi eld strength and relative permittivity of cross-linked polyethylene (XLPE) with diff erent cross-linking agent contents. Here, low-density polyethylene (LDPE) and dicumyl peroxide (DCP) are used as basic experimental material and cross-linking agent, respectively. Eventually, experimental results indicate that thermal aging can gradually make threshold fi eld strength and relative permittivity of XLPE with diff erent DCP contents increase and decrease, respectively. Besides, threshold fi eld strength of XLPE with diff erent DCP contents increases fi rst and then decreases as the increase of DCP content, while relative permittivity of XLPE with diff erent DCP contents decreases fi rst and then increases as DCP content increases at diff erent thermal aging time, etc. These studies in this article are the basis of the research on space charge accumulation and dissipation inside XLPE materials, which are of great signifi cance to the normal operation of XLPE cables.

Complete genome sequence and pathogenic genes analysis of Pectobacterium atroseptica JG10-08

Dai Zhang,Yuan Zhou,Dongmei Zhao,Zhihui Yang,Mingming Zhu,Jiehua Zhu 한국유전학회 2017 Genes & Genomics Vol.39 No.9

Pectobacterium atroseptica is known as a rod-shaped gram-negative bacterial pathogen associated with the blackleg of potato. P. atroseptica has been widely identified as the predominant agent causing tuber rot in temperate regions, a disease that leads to severe economic losses to potato industry. In this study, we provide the complete genome sequence of P. atroseptica JG10-08, which revealed that P. atroseptica strain JG10-08 carries a single 5,004,926 bp chromosome with 51.15% G+C content and harbors 4252 predicted coding genes. Phylogenetic analysis based on the genome sequences showed a close evolutionary relationship between P. atroseptica and Pectobacterium wasabiae. We discovered total 168 genes were potentially related to pathogenesis including 9 strainspecific genes encoding toxins on the genome of JG10-08. Further comparison with other species in Pectobacterium revealed a better understanding of pathogenic factors, especially secretion systems in P. atroseptica JG10-08. Collectively, the results of this research provide a solid foundation for discovering the underlying pathogenic mechanisms of P. atroseptica and offer the information to develop more effective strategies against blackleg of potatoes.

Reparation and properties of porous ceramics via re-coating technique

Zhou Mei,Dai Wubin,Zeng Lingke 한양대학교 세라믹연구소 2015 Journal of Ceramic Processing Research Vol.16 No.5

Via a polymeric foam replication and two-step route (heating and re-coating), the reticulate porous ceramics (RPCs) were fabricated. The coating slurries were made up mainly by the ceramic powder (major raw material) and silica sol (binder). The re-coating slurries were obtained by mixing the pore-forming raw material with dilute coating slurries. The effect of the solidcontents on the re-coating rate (Pr) and the porosity (θs) was investigated. The experimental results indicate that the Pr is increasing and the θs is decreasing gradually following the increase of solid-contents. The specific surface area and the pore size distribution of the sintered bodies were measured by intrusive mercury curve. Morphological characteristics of the sintered bodies were investigated by the scanning electron microscopy (SEM). The results illustrated that the pore diameter were all quite spread and the effective specific surface areas for the samples G-4, S-4 and D-4 RPCs are 0.36 m2 /g, 0.52 m2 / g and 1.63 m2 /g, respectively.

Experimental investigations on seismic response of riser in touchdown zone

Dai, Yunyun,Zhou, Jing The Society of Naval Architects of Korea 2018 International Journal of Naval Architecture and Oc Vol.10 No.3

A series of indoor simulation tests on a large-sized shaking table was performed, which was used to simulate the earthquake ground motion for the pipe-soil interaction system to be tested. The purpose of this study is to examine the dynamic characteristic and seismic response of a length of PVC pipeline lay on a clay seabed under seismic load. The pipeline was fully instrumented to provide strain and acceleration responses in both transverse and in-line. Dynamical modal tests show that corresponding mode shapes vertically and horizontally are basically the same. But the absolute values of the natural frequencies vertically are all higher than those corresponding values in transverse. It turned out that the geometry configuration of riser affects its stiffness. Seismic response of pipeline depends significantly on the waveform, and Peak Ground Acceleration (PGA). As the seismic loading progressed, the strain response was severe around both TDZ and catenary zone. Additionally, strain responses in top and bottom positions were more severe than the result in left or right side of the pipeline in the same section.

Nucleation and Growth of Bismuth Electrodeposition from Alkaline Electrolyte

Zhou, Longping,Dai, Yatang,Zhang, Huan,Jia, Yurong,Zhang, Jie,Li, Changxiong Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

The early stages of bismuth (Bi) electrodeposition on glass carbon electrode from alkaline electrolyte were studied by cyclic voltammetry, chronoamperometry, scanning electron microscopy, atomic force microscopy and X-ray diffraction. The CV analysis showed that the electrodeposition of Bi was determined to be quasireversible process with diffusion controlled. The current transients for Bi electrodeposition were analyzed according to the Scharifker-Hills model and the Heerman-Tarallo model. It can be concluded that the nucleation and growth mechanism was carried out under a 3D instantaneous nucleation, which was confirmed by SEM analysis. The kinetic growth parameters were obtained through a nonlinear fitting. In addition, the Bi film obtaining at -0.86 V for 1 hour was of compact and uniform surface with good smoothness, small roughness and a very high purity. The Bi film were indexed to rhombohedral crystal structure with preferred orientation of (0 1 2) planes to growth.

Simultaneous treatment with sorafenib and glucose restriction inhibits hepatocellular carcinoma in vitro and in vivo by impairing SIAH1-mediated mitophagy

Zhou Jing,Feng Ji,Wu Yong,Dai Hui-Qi,Zhu Guang-Zhi,Chen Pan-Hong,Wang Li-Ming,Lu Guang,Liao Xi-Wen,Lu Pei-Zhi,Su Wen-Jing,Hooi Shing Chuan,Ye Xin-Pin,Shen Han-Ming,Peng Tao,Lu Guo-Dong 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Transarterial chemoembolization (TACE) is the first-line treatment for unresectable intermediate-stage hepatocellular carcinoma (HCC). It is of high clinical significance to explore the synergistic effect of TACE with antiangiogenic inhibitors and the molecular mechanisms involved. This study determined that glucose, but not other analyzed nutrients, offered significant protection against cell death induced by sorafenib, as indicated by glucose deprivation sensitizing cells to sorafenib-induced cell death. Next, this synergistic effect was found to be specific to sorafenib, not to lenvatinib or the chemotherapeutic drugs cisplatin and doxorubicin. Mechanistically, sorafenib-induced mitophagy, as indicated by PINK1 accumulation, increased the phospho-poly-ubiquitination modification, accelerated mitochondrial membrane protein and mitochondrial DNA degradation, and increased the amount of mitochondrion-localized mKeima-Red engulfed by lysosomes. Among several E3 ubiquitin ligases tested, SIAH1 was found to be essential for inducing mitophagy; that is, SIAH1 silencing markedly repressed mitophagy and sensitized cells to sorafenib-induced death. Notably, the combined treatment of glucose restriction and sorafenib abolished ATP generation and mitophagy, which led to a high cell death rate. Oligomycin and antimycin, inhibitors of electron transport chain complexes, mimicked the synergistic effect of sorafenib with glucose restriction to promote cell death mediated via mitophagy inhibition. Finally, inhibition of the glucose transporter by canagliflozin (a clinically available drug used for type-II diabetes) effectively synergized with sorafenib to induce HCC cell death in vitro and to inhibit xenograft tumor growth in vivo. This study demonstrates that simultaneous treatment with sorafenib and glucose restriction is an effective approach to treat HCC, suggesting a promising combination strategy such as transarterial sorafenib-embolization (TASE) for the treatment of unresectable HCC.

Preoperative BRAF Mutation is Predictive of Occult Contralateral Carcinoma in Patients with Unilateral Papillary Thyroid Microcarcinoma

Zhou, Yi-Li,Zhang, Wei,Gao, Er-Li,Dai, Xuan-Xuan,Yang, Han,Zhang, Xiao-Hua,Wang, Ou-Chen Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Background and Objective: The optimal resection extent for clinically unilateral papillary thyroid microcarcinoma (PTMC) remains controversial. The objective was to investigate risk factors associated with occult contralateral carcinoma, and put emphasis on the predictive value of preoperative BRAF mutation. Materials and Methods: 100 clinically unilateral PTMC patients all newly diagnosed, previously untreated were analyzed in a prospective cohort study. We assessed the T1799A BRAF mutation status in FNAB specimens obtained from all PTMC patients before undergoing total thyroidectomy (TT) and central lymph node dissection (CLND) for PTMC. Univariate and multivariate analyses were used to reveal the incidence of contralateral occult cancer, difference of risk factors and predictive value, with respect to the following variables: preoperative BRAF mutation status, age, gender, tumor size, multifocality of primary tumor, capsular invasion, presence of Hashimoto thyroiditis and central lymph node metastasis. Results: 20 of 100 patients (20%) had occult contralateral lobe carcinoma. On multi-variate analysis, preoperative BRAF mutation (p = 0.030, OR = 3.439) and multifocality of the primary tumor (p = 0.004, OR = 9.570) were independent predictive factors for occult contralateral PTMC presence. However, there were no significant differences between the presence of occult contralateral carcinomas and age, gender, tumor size, capsular invasion, Hashimoto thyroiditis and central lymph node metastasis. Conclusions: Total thyroidectomy, including the contralateral lobe, should be considered for the treatment of unilateral PTMC if preoperative BRAF mutation is positive and/or if the observed lesion presents as a multifocal tumor in the unilateral lobe.