Effects of Quenching Methods and Aging Processes on the Crushing Properties and Microstructure of Al–Zn–Mg Alloy Thin-Walled Square Extrusions

Hui Guo,Jin Zhang,Cheng Wang,Yun‑lai Deng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In this study, the effects of different (online quenching and offline quenching) quenching methods and aging processes (T6and T73) on the crashworthiness and microstructural evolution of three Al–Zn–Mg alloys (G1–G3) were studied by conductingtensile test and axial compression tests at room temperature, combined with optical metallography, electron back scattereddiffraction, and transmission electron microscopy microstructural observations. The obtained results revealed that thecrushing properties of three different Al–Zn–Mg alloys subjected to different quenching methods and aging processes weresignificantly different. Their crushing energy absorption of are ranked as follows: G1 > G3 > G2. The highest total energyabsorption gap (between T6 and T73) is the G1 alloy, and the lowest one is the G3 alloy. The largest total energy absorptiongap between the two quenching methods is the G3 alloy, and the smallest one is the G1 alloy. The G2 alloy with the largesttotal amount of Zn + Mg has the highest number density of matrix precipitates, the largest precipitate gap (between T6 andT73) and the smallest precipitate gap between the two quenching methods. The G3 alloy with the largest Zn/Mg ratio hasthe smallest number density of matrix precipitates, the minimum precipitation gap (between T6 and T73) and the maximumprecipitation gap between the two quenching methods. The G1 alloy with the lowest Zn/Mg ratio has the smallest size ofgrain boundary precipitates and PFZ width, while their largest values are obtained for the G3 alloy with the maximum Zn/Mg ratio. As a crushing resistant structural material, the crushing properties is improved without reducing the strength. Theratio of Zn/Mg should be controlled within the range of 4.57–6.15, while the total amount of Zn + Mg should be controlledwithin the range of 6.18–7.01.

Histopathological Evidence for the Existence of Primary Liver Progenitor Cell Cancer: Insight from Cancer Stem Cell Pathobiology

( Cheng-maw Ho ),( Shu-li Ho ),( Chia-tung Shun ),( Po-huang Lee ),( Ya-hui Chen ),( Chin-sung Chien ),( Hui-ling Chen ),( Rey-heng Hu ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Primary liver progenitor cell cancer is a rare disease entity without definite evidence and characterization. Current nomenclature of primary liver cancer with prominent progenitor features is not comprehensive. This study was aimed to investigate the existence of this kind of primary liver cancer and characterize it immunohistopathologically based on the emerging understanding of cancer stem cell pathobiology. Methods: Surgical specimens from primary liver cancer which posed diagnostic difficulty fitting within current WHO classification of combined hepatocellular-cholangiocellular carcinoma with stem-cell features according to the growth morphology and its suggested immunohistochemical features, were stained with antibodies against well-defined markers of progenitor cells, stemness, and differentiation toward hepatocytes or cholangiocytes. Comparative interpretation of images was processed considering the histological morphology and characteristic markers. Results: The primary liver cancer consisted of CD24+ cancer progenitor cells and CD90+ mesenchymal stromal cells, which were intimately mixed. CD24+ cancer cells demonstrated bi-directional trends of differentiation: bile ductule transformation (cytokeratin 19+, epithelial cell adhesion molecule [EpCAM]+, neural cell adhesion molecule [NCAM]+, CD133+, and delta-like 1 homolog [DLK1]+); and trabecular or nested cell clusters toward hepatic lineage (hepatocyte nuclear factor-4 alpha [HNF-4α]+, Hep Par1+ and negative for CK19, EpCAM, CD133, and DLK1). Moderate lymphocyte (mostly CD4+ and CD8+ T cells) infiltrated in the CD90+ cancer- associated stroma. Conclusions: We provided the corroboration that liver progenitor cells can form primary liver cancer, not just presented as few side population of cancer stem cells. Its existence might pose significance for future stem cell therapeutic intervention targeting liver diseases, albeit the disease is rare.

Comparison of the Gene Expression Profiles Between Smokers With and Without Lung Cancer Using RNA-Seq

Cheng, Peng,Cheng, You,Li, Yan,Zhao, Zhenguo,Gao, Hui,Li, Dong,Li, Hua,Zhang, Tao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Lung cancer seriously threatens human health, so it is important to investigate gene expression changes in affected individuals in comparison with healthy people. Here we compared the gene expression profiles between smokers with and without lung cancer. We found that the majority of the expressed genes (threshold was set as 0.1 RPKM) were the same in the two samples, with a small portion of the remainder being unique to smokers with and without lung cancer. Expression distribution patterns showed that most of the genes in smokers with and without lung cancer are expressed at low or moderate levels. We also found that the expression levels of the genes in smokers with lung cancer were lower than in smokers without lung cancer in general. Then we detected 27 differentially expressed genes in smokers with versus without lung cancer, and these differentially expressed genes were foudn to be involved in diverse processes. Our study provided detail expression profiles and expression changes between smokers with and without lung cancer.

Hepatocyte and mesenchymal stem cell co-transplantation in rats with acute liver failure

Cheng-Maw Ho,Ya-Hui Chen,Chin-Sung Chien,Shu-Li Ho,Hui-Ling Chen,Rey-Heng Hu,Po-Huang Lee 대한이식학회 2020 Korean Journal of Transplantation Vol.34 No.2

Background: Cell therapy is considered a potential alternative to liver transplantation in acute liver failure (ALF). We aimed to evaluate the add-on therapeutic benefit of hepatocyte and mesenchymal stem cell (MSC) cotransplantation over hepatocyte-only transplantations in a rat model of ALF. Methods: ALF was induced by D-galactosamine in Sprague-Dawley rats. Freshly isolated donor hepatocytes were derived from Tg (UBC-emGFP) rats and MSCs were collected from the bone marrow cells of DsRed rats. Donor hepatocytes (1×107/mL) were intraportally transplanted 24 hours after treatment with D-galactosamine over a 70-second interval, and donor MSCs (0.5, 1, or 2×106/0.5 mL) were intraportally transplanted 1 hour after the hepatocyte transplantation was complete. Animals were sacrificed after 7 and 14 days and subjected to donor cell identification, liver histology, serologic testing, and immunohistopathological examination. Results: MSCs were observed in the periportal area, 1 and 2 weeks after transplantation. Transplanted hepatocytes did not actively proliferate when compared to hepatocyte-only transplantation. Morphologically, transplanted MSCs did not appear to differentiate into hepatocytes even 2 weeks after transplantation. Cotransplantation of MSCs was associated with lower macrophage infiltration, and reduced type I collagen, hepatocyte growth factor, tumor necrosis factor-α, and interleukin 10 expression, with similar gene expression profiles for epidermal growth factor and interleukin 6, when compared to hepatocyte-only transplantation. Conclusions: Hepatocyte and MSC cotransplantation is feasible and safe in rat models of ALF. MSCs were found to survive the process and could be located within the periportal niches 2 weeks after treatment, without enhancing transplanted hepatocyte proliferation or differentiating into hepatocytes, while ameliorating the inflammatory response.

The feasibility of detecting endometrial and ovarian cancer using DNA methylation biomarkers in cervical scrapings

Cheng-Chang Chang,Hui-Chen Wang,Yu-Ping Liao,Yu-Chih Chen,Yu-Chun Weng,Mu-Hsien Yu,Hung-Cheng Lai 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.1

Objective: We hypothesized that DNA methylation of development-related genes may occur in endometrial cancer (EC)/ovarian cancer (OC) and may be detected in cervical scrapings. Methods: We tested methylation status by quantitative methylation-specific polymerase chain reaction for 14 genes in DNA pools of endometrial and OC tissues. Tissues of EC/normal endometrium, OC/normal ovary, were verified in training set using cervical scrapings of 10 EC/10 OC patients and 10 controls, and further validated in the testing set using independent cervical scrapings in 30 EC/30 OC patients and 30 controls. We generated cutoff values of methylation index (M-index) from cervical scrapings to distinguish between cancer patients and control. Sensitivity/specificity of DNA methylation biomarkers in detecting EC and OC was calculated. Results: Of 14 genes, 4 (PTGDR, HS3ST2, POU4F3, MAGI2) showed hypermethylation in EC and OC tissues, and were verified in training set. POU4F3 and MAGI2 exhibited hypermethylation in training set were validated in independent cases. The mean M-index of POU4F3 is 78.28 in EC and 20.36 in OC, which are higher than that in controls (6.59; p<0.001 and p=0.100, respectively), and that of MAGI2 is 246.0 in EC and 12.2 in OC, which is significantly higher that than in controls (2.85; p<0.001 and p=0.480, respectively). Sensitivity and specificity of POU4F3/MAGI2 were 83%–90% and 69%–75% for detection of EC, and 61% and 62%–69% for the detection of OC. Conclusion: The findings demonstrate the potential of EC/OC detection through testing for DNA methylation in cervical scrapings.

Optimization of the microemulsion formulation of curcuma oil and evaluation of its acaricidal efficacy against Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae)

Cheng Zuo-Hui,Fan Fang-Fang,Zhao Jin-Zhong,Li Rui,Li Sheng-Cai,Zhang En-Jia,Liu Yu-Kun,Wang Jue-Ying,Zhu Xiang-Run,Tian Yong-Ming 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

The microemulsion formulation (hereafter formulation) of curcuma oil and its acaricidal efficacy against Tetranychus cinnabarinus Boisduval (Acari: Tetranychidae) were optimized in the laboratory to evaluate their spray effectiveness of oviposition inhibition and repellence. Ethovision XT6 was used to analyse the effects of the sublethal concentrations (LC 20 ) of curcuma oil and the formulation on the behaviors of T. cinnabarinus. The results showed that Tween-80 was the best surfactant, Isopropanol was the best co-surfactant and K m = 2:1 was the best condition for the formulation. The prepared microemulsions are stable under conditions of centrifugation and incubation for extended periods. The results showed that the effect of the spray bioassays of the formulation against T. cinnabarinus continuously increased during the experiment, but for curcuma oil almost no longer increase observed when the exposure time went beyond 24 h. Moreover, compared with curcuma oil (LC 50 = 0.716%), the spray bioassay of the formulation (LC 50 = 0.035%) was stronger against T. cinnabarinus. The repellency of the formulation to T. cinnabarinus was stronger with increasing exposure time, but that of curcuma oil declined after 12 h of exposure. The mobile distance of T. cinnabarinus treated with the formulation continuously declined during the experiment but that due to the curcuma oil almost no longer declined when the treatment time reached 12 h. The maximum mobile frequency of T. cinnabarinus treated by curcuma oil and the formulation was recorded at 6 h and 12 h, respectively. Thus, the formulation is a promising candidate as a botanical acaricide of green vegetables.

FEM analysis of the modular prefabricated steel-concrete composite beam-column internal joint under reciprocating action

Cheng Long Wu,Jian Cheng Kan,Qi Hui Wang,Ji Ming Liu,Zun Qiang Li 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.1

Prefabricated steel-concrete composite structure has the advantages of large bearing capacity, reliable connection, and good durability, which is of great significance to the development of building industrialization. In this paper, a finite element model (FEM) of the modular prefabricated SRC column-steel beam composite joint is established and verified its accuracy through ABAQUS. The effects of various parameter variables on the hysteresis curve, skeleton curve, ductility, energy consumption, and performance deterioration are investigated. The results show that as the axial compression ratio increases, the joint bearing capacity first increases and then decreases, the strength and stiffness have relatively stable degradation characteristics. However, the hysteresis curve has a certain “pinch” phenomenon, which reduces the energy consumption performance. Different column end bolts margin and apertures have little effect on the bearing capacity, strength and stiffness degradation performance, but affect energy consumption and ductility. The width-to-thickness ratio of the square steel tube has a greater impact on the bearing capacity, energy consumption and ductility, and has less impact on the strength and stiffness degradation performance. As the thickness of the joint cover plate increases, the bearing capacity, energy consumption and initial stiffness of the joint gradually increase, the ductility first increases and then decreases.

Ruptured Spinal Dermoid Cysts with Lipid Droplets into the Syrinx Cavity : Reports of Fourteen Cases

Cheng, Cheng,Li, Rong,Gao, Haihao,Tao, Benzhang,Wang, Hui,Sun, Mengchun,Gao, Gan,Wang, Jianzhen,Shang, Aijia The Korean Neurosurgical Society 2022 Journal of Korean neurosurgical society Vol.65 No.3

Objective : Dermoid cysts are uncommon in spinal cord tumors, and the phenomenon of their spontaneous rupture into the syrinx cavity is quite rare. We aimed to analyze the imaging characteristics and etiologies, and propose some surgical strategies, for this uncommon phenomenon. Methods : We retrospectively reviewed 14 cases with spinal dermoid cysts that ruptured into the cervical and thoracic syrinx cavity. There were six male and eight female cases, aged 21 to 46 years, who had lipid droplets in the syrinx cavity from C1 to L3. The dermoid cysts were always located at the conus. Based on patients' complaints, clinical manifestations, and imaging results, we adopted tumor excision and/or syrinx cavity aspiration in one stage or multiple stages. Results : Three patients had only a syrinx cavity aspiration surgery due to a history of dermoid cyst excision. Eight patients had dermoid cyst resection and syrinx cavity aspiration in one stage. One patient was operated upon in two stages due to the development of new symptoms at nine months follow-up. Two patients underwent only tumor resection since they did not show similar symptoms or signs caused by the cervicothoracic syrinx. The axial magnetic resonance imaging indicated that the lipid droplets were always not at the center but were eccentric. The clinical effect was satisfactory during the follow-up period in this group. Conclusion : The lipid droplets filled the spinal syrinx cavity, not entirely confined to the central canal. Based on the chief complaints and associated signs, we adopted different surgical strategies and had satisfactory clinical results.

Recycle of Crop Residues in Fields through Fermentation

Cheng-Long Yan,Xue-Feng Hu,Ming-Yang Cao,Hui-Hui Dai,Fan Luo 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

LOW TEMPERATURE SYNTHESIS OF Mg(OH)2 NANOTUBES IN AQUEOUS SOLUTIONS OF BLOCK COPOLYMER P123

HUI-MING CHENG,ZHIGANG ZHAO,FENGXIA GENG,HONGTAO CONG,JINBO BAI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2006 NANO Vol.1 No.2

A simple aqueous solution-based block-polymer-assisted method was developed for the synthesis of Mg(OH)2 nanotubes using inexpensive starting materials (MgSO4 and NaOH) with significant advance of bringing down the average outer diameter to the regime below 10 nm. The synthesized nanotubes are found to possess a relatively high specific surface area up to 64 m2/g, which may suggest their potential value for use in the catalysis field. The Barrett–Joyner–Halenda pore-size distribution plot reveals a bimodal distribution centred at 3.4 and 17.3 nm, which may be from the tunnel cavity and the aggregated pores of Mg(OH)2 nanotubes, respectively. This method can be widely used to fabricate other inorganic 1D nanostructured materials and easily realized in industrial-scale synthesis.