Effect of Oxides on Characteristics of MnS and Transverse Mechanical Properties in Commercial Al‑Killed Non‑Quenched and Tempered Steel

Jinlong Lu,Guoguang Cheng,Julong Che,Liansheng Wang,Guojian Xiong 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

In this paper, the characteristics of tensile fractures and the typical inclusions in as-cast blooms and as-rolled bars are carefullyinvestigated to figure out the causes of different transverse tensile properties in two commercial non-quenched andtempered steels. In low Ca bearing steel (3 ppm), MgO–Al2O3 (MA) + MnS are main inclusions and MA oxides expresshigh ability for MnS heterogeneous nucleation. Consequently, the MnS inclusions in as-rolled bars are larger in size andsmaller in number, the transverse ductility is satisfied due to the high space distance between the MnS inclusions. However,the transverse ductility of high Ca bearing steel (9 ppm) is much poor because MnS inclusions are agminated in distribution,causing severe stress concentration. The calculation results show that CaO in CaO–MgO–Al2O3 oxides (CMA) wouldreact with Al and S in molten steels, suppressing the formation of MnS inclusions on surface of CMA oxides. An integratedillumination including the evolution processes of typical oxides in molten steels, the generation behaviors of MnS duringthe solidification, the deformation behaviors of sulfides and the relationship between sulfides and crack initiation have beenconducted based on observation results and thermodynamic calculation.

Novel Mutations in CYP51B from Penicillium digitatum Involved in Prochloraz Resistance

Jinlong Wang,Jinhui Yu,Jing Liu,Yongze Yuan,Na Li,Muqing He,Ting Qi,Geng Hui,Li Xiong,Deli Liu 한국미생물학회 2014 The journal of microbiology Vol.52 No.9

Green mold caused by Penicillium digitatum is one of themost serious postharvest diseases of citrus fruit, and it isubiquitous in all citrus growing regions in the world. Sterol14α-demethylase (CYP51) is one of the key enzymes of sterolbiosynthesis in the biological kingdom and a prime targetof antifungal drugs. Mutations in CYP51s have been foundto be correlated with resistance to azole fungicides in manyfungal species. To investigate the mechanism of resistance toprochloraz (PRC) in P. digitatum, the PRC sensitivity wasdetermined in vitro in this study to assess the sensitivity of78 P. digitatum isolates collected in Hubei province. Theresults showed that 25 isolates were prochloraz-resistant(PRC-R), including six high-resistant (HR) strains, twelvemedium-resistant (MR) and seven low-resistant (LR) strains. A sequence analysis showed no consistent point mutationsof PdCYP51A in the PRC-R strains, but four substitutionsof CYP51B were found, Q309H in LR strains, Y136H andQ309H in HR strains, and G459S and F506I in MR strains,which corresponded to the four sensitivity levels. Based onthe sequence alignment analysis and homology modelingfollowed by the molecular docking of the PdCYP51B protein,the potential correlation between the mutations and PRC resistance is proposed.

DEAD-box RNA helicase DDX23 modulates glioma malignancy via elevating miR-21 biogenesis

Yin, Jinlong,Park, Gunwoo,Lee, Jeong Eun,Choi, Eun Young,Park, Ju Young,Kim, Tae-Hoon,Park, Nayun,Jin, Xiong,Jung, Ji-Eun,Shin, Daye,Hong, Jun Hee,Kim, Hyunggee,Yoo, Heon,Lee, Seung-Hoon,Kim, Youn-Jae Oxford University Press 2015 Brain Vol.138 No.9

<P>Upregulation of microRNA-21 (miR-21) is strongly associated with glioma malignancy, but the regulatory mechanism that governs miR-21 biogenesis is unclear. Yin <I>et al.</I> demonstrate that the DEAD-box RNA helicase DDX23 promotes miR-21 biogenesis at the post-transcriptional level in glioma cells, and that DDX23 inhibition reduces glioma growth in mouse xenografts.</P><P> [Figure] </P><P>Upregulation of microRNA-21 (miR-21) is known to be strongly associated with the proliferation, invasion, and radio-resistance of glioma cells. However, the regulatory mechanism that governs the biogenesis of miR-21 in glioma is still unclear. Here, we demonstrate that the DEAD-box RNA helicase, DDX23, promotes miR-21 biogenesis at the post-transcriptional level. The expression of DDX23 was enhanced in glioma tissues compared to normal brain, and expression level of DDX23 was highly associated with poor survival of glioma patients. Specific knockdown of DDX23 expression suppressed glioma cell proliferation and invasion <I>in vitro</I> and <I>in vivo</I>, which is similar to the function of miR-21. We found that DDX23 increased the level of miR-21 by promoting primary-to-precursor processing of miR-21 through an interaction with the Drosha microprocessor. Mutagenesis experiments critically demonstrated that the helicase activity of DDX23 was essential for the processing (cropping) of miR-21, and we further found that ivermectin, a RNA helicase inhibitor, decreased miR-21 levels by potentially inhibiting DDX23 activity and blocked invasion and cell proliferation. Moreover, treatment of ivermectin decreased glioma growth in mouse xenografts. Taken together, these results suggest that DDX23 plays an essential role in glioma progression, and might thus be a potential novel target for the therapeutic treatment of glioma.</P>

Pigment Epithelium-Derived Factor (PEDF) Expression Induced by EGFRvIII Promotes Self-renewal and Tumor Progression of Glioma Stem Cells

Yin, Jinlong,Park, Gunwoo,Kim, Tae Hoon,Hong, Jun Hee,Kim, Youn-Jae,Jin, Xiong,Kang, Sangjo,Jung, Ji-Eun,Kim, Jeong-Yub,Yun, Hyeongsun,Lee, Jeong Eun,Kim, Minkyung,Chung, Junho,Kim, Hyunggee,Nakano, I Public Library of Science 2015 PLoS biology Vol.13 No.5

<▼1><P>Epidermal growth factor receptor variant III (EGFRvIII) has been associated with glioma stemness, but the direct molecular mechanism linking the two is largely unknown. Here, we show that EGFRvIII induces the expression and secretion of pigment epithelium-derived factor (PEDF) via activation of signal transducer and activator of transcription 3 (STAT3), thereby promoting self-renewal and tumor progression of glioma stem cells (GSCs). Mechanistically, PEDF sustained GSC self-renewal by Notch1 cleavage, and the generated intracellular domain of Notch1 (NICD) induced the expression of Sox2 through interaction with its promoter region. Furthermore, a subpopulation with high levels of PEDF was capable of infiltration along corpus callosum. Inhibition of PEDF diminished GSC self-renewal and increased survival of orthotopic tumor-bearing mice. Together, these data indicate the novel role of PEDF as a key regulator of GSC and suggest clinical implications.</P></▼1><▼2><P>A permanently activated mutant form of the epidermal growth factor receptor found in glioblastoma promotes self-renewal and tumor progression by inducing autocrine signalling via pigment epithelium-derived factor (PEDF).</P></▼2><▼3><P><B>Author Summary</B></P><P>Malignant gliomas are among the most lethal types of cancer, due in part to the stem-cell-like characteristics and invasive properties of the brain tumor cells. However, little is known about the underlying molecular mechanisms that govern such processes. Here, we identify pigment epithelium-derived factor (PEDF) as a critical factor controlling stemness and tumor progression in glioma stem cells. We found that PEDF is secreted from glioblastoma expressing EGFRvIII, a frequently occurring mutation in primary glioblastoma that yields a permanently activated epidermal growth factor receptor. We delineate an EGFRvIII-STAT3-PEDF signaling axis as a signature profile of highly malignant gliomas, which promotes self-renewal of glioma stem cells. Our results demonstrate a previously unprecedented function of PEDF and implicate potential therapeutic approaches against malignant gliomas.</P></▼3>

Inhibition of ID1–BMPR2 Intrinsic Signaling Sensitizes Glioma Stem Cells to Differentiation Therapy

Jin, Xiong,Jin, Xun,Kim, Leo J.Y.,Dixit, Deobrat,Jeon, Hee-Young,Kim, Eun-Jung,Kim, Jun-Kyum,Lee, Seon Yong,Yin, Jinlong,Rich, Jeremy N.,Kim, Hyunggee American Association for Cancer Research 2018 Clinical Cancer Research Vol.24 No.2

<P><B>Purpose:</B> Normal stem cells tightly control self-renewal and differentiation during development, but their neoplastic counterparts, cancer stem cells (CSCs), sustain tumorigenicity both through aberrant activation of stemness and evasion of differentiation. Although regulation of CSC stemness has been extensively studied, the molecular mechanisms suppressing differentiation remain unclear.</P><P><B>Experimental Design:</B> We performed <I>in silico</I> screening and <I>in vitro</I> validation studies through Western blotting, qRT-PCR for treatment of WNT and SHH signaling inhibitors, and BMP signaling inducer with control and ID1-overexpressing cells. We also performed <I>in vivo</I> drug treatment assays with Balb/c nude mice.</P><P><B>Results:</B> Inhibitor of differentiation 1 (ID1) abrogated differentiation signals from bone morphogenetic protein receptor (BMPR) signaling in glioblastoma stem cells (GSCs) to promote self-renewal. ID1 inhibited BMPR2 expression through miRNAs, miR-17 and miR-20a, which are transcriptional targets of MYC. ID1 increases MYC expression by activating WNT and SHH signaling. Combined pharmacologic blockade of WNT and SHH signaling with BMP treatment significantly suppressed GSC self-renewal and extended survival of tumor-bearing mice.</P><P><B>Conclusions:</B> Collectively, our results suggested that ID1 simultaneously regulates stemness through WNT and SHH signaling and differentiation through BMPR-mediated differentiation signaling in GSCs, informing a novel therapeutic strategy of combinatorial targeting of stemness and differentiation. <I>Clin Cancer Res; 24(2); 383–94. ©2017 AACR</I>.</P>

A Novel Active Current Disturbance Method Based on Discrete Wavelet Analysis

Wu Tiezhou,Xiong Jinlong,Wu Xiaomin,Luo Meng 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.12

Islanding detection method of active current disturbances in three-phase photovoltaic-to-grid system makes the common connection point (PCC) voltage appear high frequency components on account of load variation, the surge current occurrence and other factors. This high frequency component cause islands misjudgment. Using Db10 wavelet to detect and analysis PCC’s voltage high-frequency components on real-time based on the active current disturbances principle. And selecting an effective wavelet domain values as the voltage harmonic detection amount islanding detection. Islands simulation test is conducted in the case of the inverter output power and load input power to match, the test results show that this method can quickly detect islanding, and effectively prevent pseudo-island phenomenon of false positives.