Imaging Manifestations and Misdiagnosis Analysis of Six Cases of Bone Hydatid Disease

Yanqiu Sun,Chunlong Yan,Dengfeng Tian,Chenhong Zhang,Qiang Zhang 대한기생충학ㆍ열대의학회 2022 The Korean Journal of Parasitology Vol.60 No.6

We retrospectively evaluated the clinical and imaging features of 6 patients with bone hydatid disease confirmed by surgery and pathological examination. Among the 6 patients, 2 were infected with Echinococcosis granulosus metacestode and 4 were infected with E. multilocularis metacestode. The 2 cases with cystic echinococcosis were diagnosed by computed tomographic (CT) examination, and other 4 cases were diagnosed by magnetic resonance (MR) imaging. On the initial evaluation, 1 case each was misdiagnosed as a giant cell tumor or neurogenic tumor, and 2 were misdiagnosed as tuberculosis. The imaging manifestations of bone hydatid disease are complex, but most common findings include expansive osteolytic bone destruction, which may be associated with sclerosing edges or dead bone formation, localized soft tissue masses, and vertebral lesions with wedge-shaped changes and spinal stenosis. Combining imaging findings with the patient’s epidemiological history and immunological examinations is of great help in improving the diagnosis and differential diagnosis of bone hydatid disease.

Influence of heat treatment on complex-shape rotating disk subjected to isothermal precision forging

Yanqiu Zhang,Shuyong Jiang,Xiaoming Zhu,Yanan Zhao,Debin Shan 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.1

Influence of heat treatment on the mechanical properties of the forging was systematically investigated according to tensile test, hardness test and electrical conductivity test. Simultaneously, typical microstructures of the 7A09 aluminum alloy samples subjected to various solution temperatures and aging regimes were characterized by means of Transmission electron microscope (TEM) and Scanning electron microscope (SEM). In the case of the different solution temperatures, the size of precipitations increases with the increase in the solution temperature, which contributes to improving both strength and stress corrosion resistance of the forging. The solution temperature of 465 °C leads to the well comprehensive mechanical properties and the superior stress corrosion resistance of the forging. G.P. zone, η' phase and η phase are able to precipitate in the matrix of the forging in the case of different aging regimes, such as peak aging, two-stage overaging, two-stage aging, and regression and re-aging. The precipitation phases play an important role in enhancing the mechanical properties of the forging as an obstacle against the dislocation movement.

Negative electrode structure design in InSb focal plane array detector for deformation reduction

Xiaoling Zhang,Qingduan Meng,Liwen Zhang,Yanqiu Lv 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6

When an indium antimonide (InSb) infrared focal plane array (IRFPA) is subjected to a thermal shock test, most of the cracks originatefrom the region over the negative electrode, which restricts its final yield. In light of the proposed equivalent modeling, three negativeelectrode structures are assessed to eliminate the accumulated deformation around the negative electrode. Simulation results show thatwhen a thicker indium bump array is connected directly with negative InSb material, the accumulated thermal deformation is the minimum,the top surface of InSb chip is the smoothest, and the square checkerboard buckling pattern, present clearly in both gold bufferlayer and sparse thicker indium bump array structure, seems to be unclear. All these mean that a thicker indium bump array structure is agood choice, which will benefit to reduce fracture probability of InSb IRFPAs under thermal shock.

Thermal buckling analysis in InSb focal plane arrays detector

Xiaoling Zhang,Qingduan Meng,Qian Yu,Liwen Zhang,Yanqiu Lv 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6

When exploring the buckling mechanism in indium antimonide (InSb) detector, the global square checkerboard buckling pattern reappears in finite element simulation results. The contributions from the three layered materials to the deformations along the Z-direction are systematically analyzed. Analysis of results shows that the buckling deformation originated from the thermal difference between silicon readout integrated circuits (silicon-ROIC) and the intermediate layer directly above. Furthermore, the buckling pattern is determined by indium bumps array. After passing through the 10 μm intermediate layer, the deformation amplitude is significantly reduced from 2.23μm to 0.24 μm. Afterwards, passing upward through the 10 μm InSb chip, the maximal deformation is further decreased to 0.09 μm.

Strain Response Regularity and Viscoplastic Model of Asphalt Binder and Asphalt Mastic Based on Repeated Creep and Recovery Test

Yanqiu Bi,Yong Wen,Jianzhong Pei,Jiupeng Zhang,Rui Li 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.3

As a viscoelastic material, asphalt mixture mainly derives its viscoelastic properties from the asphalt binder. This research aims to comparatively evaluate the strain response regularity of asphalt binder and asphalt mastic through repeated creep and recovery (RCR) test indices. The influences of the asphalt binders, filler volume fraction and filler type on the strain response indices: deformation recovery rate (R) and non-recoverable creep compliance (Jnr) were analyzed according to the RCR test results of the mastics. The viscoplastic (VP) model for characterizing asphalt binder and asphalt mastic behavior was described. The parameters of the model were determined in the prepeak region of the loading, under different stress levels. Simultaneously, the prediction accuracy of the developed VP model was verified, and the applicability of the model was analyzed. The filler volume fraction has the most significant effect on the strain response of the mastic. The R value decreases but the Jnr value increases with the filler volume fractions. The average non-recoverable percent Jnr value decreases with the aging degree increasing. Compared with the unaged (OR) mastics, the Jnr values after rolling thin film oven test (RTFOT) and pressure aging vessel (PAV) decreases by more than 20% and 88%. The improved strain hardening VP model can better simulate the viscoplastic strain response of the asphalt binder and mastic in the RCR test, and the prediction accuracy was greatly improved. The prediction accuracy slightly decreased with creep time increasing. Further research shows that the improved strain hardening VP model is also applicable to the calculation of viscoplastic strains in the RCR test of the asphalt binder and the mastic after RTFOT aging and PAV aging. The improved VP model increases from 5% to 92% off the reference line to within 3%.

Strain-Rate Effect on the Stress and Strain Concentration in a Visco-Plastic Plate With An Elliptic Hole

Yanqiu Chen,Jin Zhang,Peishi Yu,Jian Wu,Weibo Wang,Junhua Zhao 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.4

The stress and strain concentration in some component has been a signifi cant topic for structural safety assessment. However, the evaluation of the stress and strain concentration based on the widely existing solutions for linear elastic material under static loading would lead to remarkable errors when the material undergoes the dynamic loading, since the coupling eff ect induced by the nonlinearity of the stress–strain relationship and the strain-rate strengthening could be of signifi cant infl uence. Here we analyzed the strain-rate dependent concentration of stress and strain for a visco-plastic plate with an elliptic hole subjected to dynamic loading. The three-dimensional stress and strain are calculated by fi nite element analyses based on a rate-dependent Johnson–Cook model in which the material constants are set according to a typical visco-plastic standard 45 carbon steel. Our results show that both the plastic stress and strain concentration factors signifi cantly depend on not only the strain but also the strain rate. With the increment of the remote strain rate, the stress concentration monotonically increases, while the strain concentration shows decreasing tendency.

Evaluation and application of constitutive promoters for cutinase production by Saccharomyces cerevisiae

Juan Zhang,Yanqiu Cai,Guocheng Du,Jian Chen,Miao Wang,Zhen Kang 한국미생물학회 2017 The journal of microbiology Vol.55 No.7

Cutinase as a promising biocatalyst has been intensively studied and applied in processes targeted for industrial scale. In this work, the cutinase gene tfu from Thermobifida fusca was artificially synthesized according to codon usage bias of Saccharomyces cerevisiae and investigated in Saccharomyces cerevisiae. Using the α-factor signal peptide, the T. fusca cutinase was successfully overexpressed and secreted with the GAL1 expression system. To increase the cutinase level and overcome some of the drawbacks of induction, four different strong promoters (ADH1, HXT1, TEF1, and TDH3) were comparatively evaluated for cutinase production. By comparison, promoter TEF1 exhibited an outstanding property and significantly increased the expression level. By fed-batch fermentation with a constant feeding approach, the activity of cutinase was increased to 29.7 U/ml. The result will contribute to apply constitutive promoter TEF1 as a tool for targeted cutinase production in S. cerevisiae cell factory.

Unit method-a universal way to simulate the process of biomass pyrolysis

( Long Yanqiu ),( Zhou Hui ),( Meng Aihong ),( Zhang Yanguo ) 한국폐기물자원순환학회 2023 I-CIPEC Vol.2012 No.0

Refolding Behavior of Urea-Induced Denaturation Collagen

Xu Wei,Yanqiu Zhao,Jingjing Zheng,Qin Cao,Sheng Li,Lang He,Benmei Wei,Juntao Zhang,Chengzhi Xu,Haibo Wang 한국고분자학회 2021 Macromolecular Research Vol.29 No.6

Exploration of the denaturation and refolding of natural collagen is important for the application of collagen and its denatured products. In this study, using urea as a denaturant, we prepared a denatured natural collagen product and analyzed its structural changes. The denaturation treatment severely destroyed the triple helix conformation of collagen, but had no significant effect on the primary structure of its α chains or the covalent cross-linking between α chains. Next, we observed the refolding behavior of the denatured collagen by removing urea through dialysis. We found that the denatured collagen products from different sources (grass carp skin, bovine tendon) all showed a reconstruction of the triple helix conformation up to 60-75% of the value of natural collagen during the refolding process. The telopeptide did not significantly promote triple helix reconstruction. In conclusion, the reconstruction of the α chains did not perfectly occur in a “head-to-head, tail-to-tail” manner in refolded collagen, as each α chain was participating in the reconstruction of multiple triple helix domains. The refolded collagen still had weak self-assembly ability and formed a unique network-like structure containing small interlaced and closely combined fibers, which shows favorable cell compatibility and potential applications.

Identification of Transmembrane Domain of a Membrane Associated Protein NS5 of Dendrolimus punctatus Cytoplasmic Polyhedrosis Virus

Chen, Wuguo,Zhang, Jiamin,Dong, Changjin,Yang, Bo,Li, Yanqiu,Liu, Chuanfeng,Hu, Yuanyang Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.4

We examined the intracellular localization of NS5 protein of Dendrolimus punctatus cytoplasmic polyhedrosis virus (DpCPV) by expressing NS5-GFP fusion protein and proteins from deletion mutants of NS5 in baculovirus recombinant infected insect Spodoptera frugiperda (Sf-9) cells. It was found that the NS5 protein was present at the plasma membrane of the cells, and that the N-terminal portion of the protein played a key role in the localization. A transmembrane region was identified to be present in the N-terminal portion of the protein, and the detailed transmembrane domain (SQIHMVWVKSGLVFF, 57-71aa) of N-terminal portion of NS5 was further determined, which was accorded with the predicted results, these findings suggested that NS5 might have an important function in viral life cycle.