Grain Morphology and Orientation Effect on the High‑Temperature Tensile Behavior of Directionally Solidified Magnesium Alloy

Qin Tang,Xiaoping Lin,Shengshi Zhao,Yi Niu,Heng Sun,Yun Dong 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.4

Columnar-structured Mg97.27Zn2.54Y0.19alloy with the preferred growth direction of ⟨22̄45⟩ and ⟨12̄33⟩, andMg98.01Zn1.84Y0.13Zr0.03alloy with the preferred growth direction of ⟨11̄20⟩ were prepared using the directional solidificationtechnique and then tensile tested at 250–300 °C. The results showed that the Mg97.27Zn2.54Y0.19alloy with columnar dendriticstructure experienced a significant deformation strengthening period when stretched at 250 °C, and a typical dynamicrecrystallization stage at 300 °C, which were mainly accounted for its well-developed secondary dendrites, a large numberof branch-shaped second phases distributed in the longitudinal grain boundary, and less granular second phases existingin the crystal. While in the whole test temperature range (250–300 °C), the stress–strain curves of Mg98.01Zn1.84Y0.13Zr0.03alloys with cellular dendritic crystals showed a steady deformation state because of the second phases with strip distributingin the longitudinal grain boundary, which was induced by a balance between the deformation strengthening and the dynamicrecrystallization. Especially at 300 °C, this steady deformation state existed in the strain of 5.6%–36%. The good uniformplastic deformation was closely related to the small misorientations between columnar grains, the associated movement ofgrains by grain boundary slipping, and the less percentage of dynamically recrystallized grains which could do harm to theorientation continuity of the columnar crystals.

Functional RsaI/PstI Polymorphism in Cytochrome P450 2E1 Contributes to Bladder Cancer Susceptibility: Evidence from a Meta-analysis

Deng, Xiao-Dong,Gao, Qin,Zhang, Bo,Zhang, Li-Xia,Zhang, Wei,Er, Zhe-Er Mu,Xie, Ying,Ma, Ying,Liu, Yun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: Cytochrome P450 2E1 (CYP2E1) might be involved in the development of bladder cancer. However, previous studies of any association between CYP2E1 RsaI/PstI polymorphism and bladder cancer risk have yielded conflicting results. In this study, we performed a more precise estimation of the relationship by a meta-analysis based on the currently available evidence from the literature. Method: To assess the effect of CYP2E1 RsaI/PstI polymorphism on bladder cancer susceptibility, a meta-analysis of 6 available studies with 1,510 cases and 1,560 controls were performed through Feb 2014. Summary odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to estimate the strength of association for CYP2E1 RsaI/PstI polymorphism under different genetic models. Results: When available studies were pooled into the meta-analysis, we found that the C1C2 and C2C2 genotypes of CYP2E1 RsaI/PstI polymorphism significantly decreased bladder cancer risk under different genetic models (heterozygote: OR=0.766, 95%CI=0.613-0.957, $P_{OR}$=0.019; homozygote: OR=0.51, 95%CI=0.303-0.858, $P_{OR}$=0.011; dominant: OR=0.733, 95%CI=0.593-0.905, $P_{OR}$=0.004; recessive: OR=0.565, 95%CI=0.337-0.947, $P_{OR}$=0.030). Subgroup analysis indicated that C2C2 genotype was significantly associated with decreased bladder cancer risk under the homozygote genetic model in Caucasians. There was no evidence of heterogeneity or publication bias. Conclusions: The current meta-analysis suggested that the CYP2E1 RsaI/PstI polymorphism might be associated with bladder cancer susceptibility, especially in Caucasians. Further studies are needed to validate the above conclusion.

Application of Intraoperative Ultrasonography for Guiding Microneurosurgical Resection of Small Subcortical Lesions

Jia Wang,Yun You Duan,Xi Liu,Yu Wang,Guo Dong Gao,Huai Zhou Qin,Liang Wang 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.5

Objective: We wanted to evaluate the clinical value of intraoperative ultrasonography for real-time guidance when performing microneurosurgical resection of small subcortical lesions. Materials and Methods: Fifty-two patients with small subcortical lesions were involved in this study. The pathological diagnoses were cavernous hemangioma in 25 cases, cerebral glioma in eight cases, abscess in eight cases, small inflammatory lesion in five cases, brain parasite infection in four cases and the presence of an intracranial foreign body in two cases. An ultrasonic probe was sterilized and lightly placed on the surface of the brain during the operation. The location, extent, characteristics and adjacent tissue of the lesion were observed by high frequency ultrasonography during the operation. Results: All the lesions were located in the cortex and their mean size was 1.3 ± 0.2 cm. Intraoperative ultrasonography accurately located all the small subcortical lesions, and so the neurosurgeon could provide appropriate treatment. Different lesion pathologies presented with different ultrasonic appearances. Cavernous hemangioma exhibited irregular shapes with distinct margins and it was mildly hyperechoic or hyperechoic. The majority of the cerebral gliomas displayed irregular shapes with indistinct margins, and they often showed cystic and solid mixed echoes. Postoperative imaging identified that the lesions had completely disappeared, and the original symptoms of all the patients were significantly alleviated. Conclusion: Intraoperative ultrasonography can help accurately locate small subcortical lesions and it is helpful for selecting the proper approach and guiding thorough resection of these lesions. Objective: We wanted to evaluate the clinical value of intraoperative ultrasonography for real-time guidance when performing microneurosurgical resection of small subcortical lesions. Materials and Methods: Fifty-two patients with small subcortical lesions were involved in this study. The pathological diagnoses were cavernous hemangioma in 25 cases, cerebral glioma in eight cases, abscess in eight cases, small inflammatory lesion in five cases, brain parasite infection in four cases and the presence of an intracranial foreign body in two cases. An ultrasonic probe was sterilized and lightly placed on the surface of the brain during the operation. The location, extent, characteristics and adjacent tissue of the lesion were observed by high frequency ultrasonography during the operation. Results: All the lesions were located in the cortex and their mean size was 1.3 ± 0.2 cm. Intraoperative ultrasonography accurately located all the small subcortical lesions, and so the neurosurgeon could provide appropriate treatment. Different lesion pathologies presented with different ultrasonic appearances. Cavernous hemangioma exhibited irregular shapes with distinct margins and it was mildly hyperechoic or hyperechoic. The majority of the cerebral gliomas displayed irregular shapes with indistinct margins, and they often showed cystic and solid mixed echoes. Postoperative imaging identified that the lesions had completely disappeared, and the original symptoms of all the patients were significantly alleviated. Conclusion: Intraoperative ultrasonography can help accurately locate small subcortical lesions and it is helpful for selecting the proper approach and guiding thorough resection of these lesions.

Anti-inflammatory effect of hispidin on LPS induced macrophage inflammation through MAPK and JAK1/STAT3 signaling pathways

Han Ying-Hao,Chen Dong-Qin,Jin Mei-Hua,Jin Ying-Hua,Li Jing,Shen Gui-Nan,Li Wei-Long,Gong Yi-Xi,Mao Ying-Ying,Xie Dan-Ping,Lee Dong-Seok,Yu Li-Yun,Kim Sun-Uk,김지수,권태호,Cui Yu-Dong,Sun Hu-Nan 한국응용생명화학회 2020 Applied Biological Chemistry (Appl Biol Chem) Vol.63 No.3

Severe inflammatory reactions caused by macrophage activation can trigger a systemic immune response. In the present study, we observed the anti-inflammatory properties of hispidin on LPS induced RAW264.7 macrophage cells. Our results showed that hispidin treatment significantly reduced the production of cellular NO, IL-6 and reactive oxygen species (ROS) while has not inhibitory effect on TNF-α productions. Excitingly, hispidin treatment retains the phagocytosis ability of macrophages which enabling them to perform the function of removing foreign invaders. Signaling studies showed, hispidin treatment dramatic suppressed the LPS induced mitogen activated protein kinases (MAPK) and JAK/STAT activations. In conclusion, our findings suggest that hispidin may be a new therapeutic target for clinical treatment of macrophages-mediated inflammatory responses.

Mechanical behavior of rock-coal-rock specimens with different coal thicknesses

Guo, Wei-Yao,Tan, Yun-Liang,Yu, Feng-Hai,Zhao, Tong-Bin,Hu, Shan-Chao,Huang, Dong-Mei,Qin, Zhe Techno-Press 2018 Geomechanics & engineering Vol.15 No.4

To explore the influence of coal thickness on the mechanical behavior and the failure characteristics of rock-coal-rock (RCR) mass, the experimental investigation of uniaxial compressive tests was conducted first and then a systematic numerical simulation by particle flow code (PFC2D) was performed to deeply analyze the failure mechanical behavior of RCR specimens with different coal thicknesses in conventional compression tests. The overall elastic modulus and peak stress of RCR specimens lie between the rock and the coal. Inter-particle properties were calibrated to match the physical sample strength and the stiffness response. Numerical simulation results show that the deformation and strength behaviors of RCR specimens depend not only on the coal thickness, but also on the confining pressure. Under low confining pressures, the overall failure mechanism of RCR specimen is the serious damage of coal section when the coal thickness is smaller than 30 mm, but it is shear failure of coal section when the coal thickness is larger than 30 mm. Whereas under high confining pressures, obvious shear bands exist in both the coal section and the rock section when the coal thickness is larger than 30 mm, but when the coal thickness is smaller than 30mm, the failure mechanism is serious damage of coal section and shear failure of rock section.

Experimental and theoretical studies of drug-polymer interactions to control the drug distributions in dissolving microneedles

Jing Ling Liu,Yun Hao Feng,Xiao Peng Zhang,Dan Dan Zhu,Li Qin Zhang,Xin Dong Guo 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.84 No.-

Dissolving microneedles (DMNs) have attracted extensive attention for transdermal drug delivery inrecent years. Generally, the skin elasticity impedes DMNs to fully insert into skin thus optimizedfabrication methods are needed to improve delivery efficiency. Here, we investigated the formulations ofDMNs as the main influencing factors during the microneedle preparation process. Through the selectionof the matrix materials and the optimization of the ratio and formulae, the DMNs can meet therequirements of convenient and effective drug delivery. For DMNs prepared with polyvinyl alcohol (PVA)as matrix material, the 25 wt% concentration of PVA was beneficial to prepare MNs, which MNs was ableto focus drug on the part of MN tips. However, for DMNs fabricated with hyaluronic acid (HA), theincreasing material concentration had a weaker ability to concentrate drug in MNs and increasedthe difficulty of preparing MNs. The computer simulation analysis was consistent with the results of theexperiment, indicating the feasibility of modelling to investigate the preparation technology of DMNsthat offer appropriate, convenient and highly efficient drug delivery.

Overexpression of NDRG2 Can Inhibit Neuroblastoma Cell Proliferation through Negative Regulation by CYR61

Zhang, Zhi-Guo,Li, Gang,Feng, Da-Yun,Zhang, Jian,Zhang, Jing,Qin, Huai-Zhou,Ma, Lian-Ting,Gao, Guo-Dong,Wu, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Several recent studies have showed that the n-myc downstream regulated gene 2 (NDRG2) is a new tumor suppressor gene, and that it plays an important role in tumor suppression in several cancers or cancer cell lines. However, few studies focused on its function in neuroblastoma cells. In the present investigation, we demonstrated that NDRG2 overexpression inhibited their proliferation. Using a cDNA microarray, we found that overexpression of NDRG2 inhibited the expression of cysteine-rich protein 61 (CYR61), a proliferation related gene. From our research, CYR61 may partially hinder NDRG2-mediated inhibition of cell proliferation. Overexpression of NDRG2 resulted in accumulation of cells in the G1 phase, which was accompanied by upregulation of p21 and p27 and downregulation of CDK4 and cyclin D1. Taken together, these data indicate that NDRG2 inhibits the proliferation of neuroblastoma cells partially through suppression of CYR61. Our findings offer novel insights into the physiological roles of NDRG2 in neuroblastoma cell proliferation, and NDRG2 may prove to be effective candidate for the treatment of children with neuroblastoma.

A New Triterpenoid from Brucea javanica

Jian Hua Liu,Jiang Jiang Qin,Hui Zi Jin,Xiao Jia Hu,Ming Chen,Yun Heng Shen,Shi Kai Yan,Wei Dong Zhang 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.5

A new triterpenoid, bruceajavanin C (1), together with bruceosides A and B (2 and 3), bruceines D and E (4 and 5), yadanziosides A and G (6 and 7), (20R)-O-(3)-α-L-arabinopyranosylpregn- 5-ene-3β,20-diol (8), and α-D-glucopyranoside, (3β, 20R)-3-hydroxypregn-5-en-20-yl (9) were isolated from the aerial parts of Brucea javanica. The structure of 1 was elucidated on the basis of 2D-NMR spectroscopic analysis. In addition, compounds 1, 3, 4, 5, and 6 exhibited mild inhibitory effect on NO production in LPS-stimulated RAW264.7 cells.

Impact of selected fungi from an artificial diet on the growth and development of Drosophila suzukii (Diptera: Drosophilidae)

Huan-Huan Gao,Nan Xu,Hao Chen,Qian Liu,Qian-Yun Pu,Dong-Yun Qin,Yi-Fan Zhai,Yi Yu 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.1

Drosophila suzukii (Diptera: Drosophilidae) is one of the very few Drosophila species which are able to lay eggs and feed on healthy ripening fruit. Adults and larvae are all able to obtain the nutrition in the decaying food, which will generate many microorganisms. However, the relationship between D. suzukii and microorganism is poorly understood. In this study, 13 species of fungi were identified in an artificial diet fed by D. suzukii. Short-term and continuously life table experiments were conducted to determine the impact of three of these fungus species including Geotrichum candidum, Talaromyces minioluteus and Actinomucor elegans on the growth and development of Drosophila suzukii. Results revealed that, compared to the control, G. candidum, T.minioluteus and A. elegans increased the mortality of D. suzukii adults in the short time, while extended the developmental time of pupal D. suzukii by 18.00%, 16.22% and 26.44%, respectively in the life table experiment. T. minioluteus reduced the total longevity of D. suzukii by 15.52%, while A. elegans enhanced the total longevity by 25.96%. G. candidum and A. elegans increased the fecundity bymore than two folds. T. minioluteus elongated the mean generation time (T) by 31.34%, whereas G. candidum shortened it by 15.26% but increased the net reproductive rate (R0) by 217.76%, intrinsic rate of increase (r) by 88.89% and finite rate of increase (λ) by 9.17%. It was concluded that G. candidumand A. elegans significantly had the beneficial effect on the growth and reproduction of D. suzukii, however, T. minioluteus had the negative effect on D. suzukii. Our results could provide a new integrated pest management strategy for D. suzukii which would be discussed in this study.

Subcellular Characterization of Porcine Oocytes with Different Glucose-6-phosphate Dehydrogenase Activities

Fu, Bo,Ren, Liang,Liu, Di,Ma, Jian-Zhang,An, Tie-Zhu,Yang, Xiu-Qin,Ma, Hong,Zhang, Dong-Jie,Guo, Zhen-Hua,Guo, Yun-Yun,Zhu, Meng,Bai, Jing Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.12

The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.