Temporary formation of highly conducting domain walls for non-destructive read-out of ferroelectric domain-wall resistance switching memories

Jiang, Jun,Bai, Zi Long,Chen, Zhi Hui,He, Long,Zhang, David Wei,Zhang, Qing Hua,Shi, Jin An,Park, Min Hyuk,Scott, James F.,Hwang, Cheol Seong,Jiang, An Quan Nature Publishing Group, a division of Macmillan P 2018 NATURE MATERIALS Vol.17 No.1

Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO<SUB>3</SUB> thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.

Increased Serotonin Signaling Contributes to the Warburg Effect in Pancreatic Tumor Cells Under Metabolic Stress and Promotes Growth of Pancreatic Tumors in Mice

Jiang, Shu-Heng,Li, Jun,Dong, Fang-Yuan,Yang, Jian-Yu,Liu, De-Jun,Yang, Xiao-Mei,Wang, Ya-Hui,Yang, Min-Wei,Fu, Xue-Liang,Zhang, Xiao-Xin,Li, Qing,Pang, Xiu-Feng,Huo, Yan-Miao,Li, Jiao,Zhang, Jun-Feng Elsevier 2017 Gastroenterology Vol.153 No.1

<P><B>Background & Aims</B></P> <P>Desmoplasia and poor vascularity cause severe metabolic stress in pancreatic ductal adenocarcinomas (PDACs). Serotonin (5-HT) is a neuromodulator with neurotransmitter and neuroendocrine functions that contributes to tumorigenesis. We investigated the role of 5-HT signaling in the growth of pancreatic tumors.</P> <P><B>Methods</B></P> <P>We measured the levels of proteins that regulate 5-HT synthesis, packaging, and degradation in pancreata from Kras<SUP>G12D/+</SUP>/Trp53<SUP>R172H/+</SUP>/Pdx1-Cre (KPC) mice, which develop pancreatic tumors, as well as in PDAC cell lines and a tissue microarray containing 81 human PDAC samples. We also analyzed expression levels of proteins involved in 5-HT synthesis and degradation by immunohistochemical analysis of a tissue microarray containing 311 PDAC specimens, and associated expression levels with patient survival times. 5-HT level in 14 matched PDAC tumor and non-tumor tissues were analyzed by ELISA. PDAC cell lines were incubated with 5-HT and cell survival and apoptosis were measured. We analyzed expression of the 5-HT receptor HTR2B in PDAC cells and effects of receptor agonists and antagonists, as well as HTR2B knockdown with small hairpin RNAs. We determined the effects of 5-HT stimulation on gene expression profiles of BxPC-3 cells. Regulation of glycolysis by 5-HT signaling via HTR2B was assessed by immunofluorescence and immunoprecipitation analyses, as well as by determination of the extracellular acid ratio, glucose consumption, and lactate production. Primary PDACs, with or without exposure to SB204741 (a selective antagonist of HTR2B), were grown as xenograft tumors in mice, and SB204741 was administered to tumor-bearing KPC mice; tumor growth and metabolism were measured by imaging analyses.</P> <P><B>Results</B></P> <P>In immunohistochemical analysis of a tissue microarray of PDAC specimens, increased levels of TPH1 and decreased level of MAOA, which regulate 5-HT synthesis and degradation, correlated with stage and size of PDACs and shorter patient survival time. We found levels of 5-HT to be increased in human PDAC tissues compared with non-tumor pancreatic tissues, and PDAC cell lines compared with non-transformed pancreatic cells. Incubation of PDAC cell lines with 5-HT increased proliferation and prevented apoptosis. Agonists of HTR2B, but not other 5-HT receptors, promoted proliferation and prevented apoptosis of PDAC cells. Knockdown of HTR2B in PDAC cells, or incubation of cells with HTR2B inhibitors, reduced their growth as xenograft tumors in mice. We observed a correlation between 5-HT and glycolytic flux in PDAC cells; levels of metabolic enzymes involved in glycolysis, the phosphate pentose pathway, and hexosamine biosynthesis pathway increased significantly in PDAC cells following 5-HT stimulation. 5-HT stimulation led to formation of the HTR2B–LYN–p85 complex, which increased PI3K–Akt–mTOR signaling and the Warburg effect by increasing protein levels of MYC and HIF1A. Administration of SB204741 to KPC mice slowed growth and metabolism of established pancreatic tumors and prolonged survival of the mice.</P> <P><B>Conclusions</B></P> <P>Human PDACs have increased levels of 5-HT, and PDAC cells increase expression of its receptor, HTR2B. These increases allow for tumor glycolysis under metabolic stress and promote growth of pancreatic tumors and PDAC xenograft tumors in mice.</P>

Expression HpaG(Xooc) Protein in Bacillus subtilis and its Biological Functions

( Hui Jun Wu ),( Shuai Wang ),( Jun Qing Qiao ),( Jun Liu ),( Jiang Zhan ),( Xue Wen Gao ) 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.2

Improving the electrical performance of HfInZnO-TFTs by introducing a thin ITO interlayer

Jun Li,Xing-Wei Ding,Jianhua Zhang,Wen-Qing Zhu,Xue-Yin Jiang,Zhi-Lin Zhang 한국물리학회 2014 Current Applied Physics Vol.14 No.8

We have fabricated hafniumeindiumezinc-oxide (HfInZnO) thin film transistors (TFT) with indiumetinoxide (ITO) interlayer. Compared with conventional HfInZnO-TFT, the electrical performance and bias stability of HfInZnO-TFTs with ITO interlayer are improved. HfInZnO-TFT with 4-nm-thick ITO interlayer shows a high mobility of 7.2 cm2/V s, a low threshold voltage of 0.13 V and a better bias stability. The performance enhancement is attributed to a decrease in interface trap state and an increase in carrier concentration. It suggests that introducing ITO interlayer at the ALD Al2O3/HfInZnO interface is an effective way to improve the electrical performance and bias stability.

Suppression of bias stress-induced degradation of pentacene-TFT using MoOx interlayer

Jun Li,Hua-Ping Lin,Fang Zhou,Wen-Qing Zhu,Xue-Yin Jiang,Zhi-Lin Zhang 한국물리학회 2012 Current Applied Physics Vol.12 No.1

The bias stress effect in pentacene thin-film transistors (TFTs) with and without MoOx interlayer was characterized. The device without MoOx interlayer showed a large threshold voltage shift of 5.1 V after stressing with a constant gate-source voltage of 40 V for 10000 s, while at the same condition, the device with MoOx interlayer showed a low threshold voltage shift of 1.9 V. The results can be attributed to the stable interface between MoOx/pentacene and small contact resistance change for the device with MoOx/Cu electrode. Pentacene-TFTs with MoOx interlayer showed a high field-effect mobility of 0.61 cm2/V s and excellent bias stability, which could be a significant step toward the commercialization of OTFT technology.

Clinical Model for Predicting Hepatocellular Carcinomas in Patients with Post-Sustained Virologic Responses of Chronic Hepatitis C: A Case Control Study

( Qing-lei Zeng ),( Bing Li ),( Xue-xiu Zhang ),( Yan Chen ),( Yan-ling Fu ),( Jun Lv ),( Yan-min Liu ),( Zu-jiang Yu ) 대한소화기학회 2016 Gut and Liver Vol.10 No.6

Background/Aims: No clinical model exists to predict the occurrence of hepatocellular carcinoma in sustained virologic response-achieving (HCC after SVR) patients with chronic hepatitis C (CHC). Methods: We performed a case-control study using a clinical database to research the risk factors for HCC after SVR. A predictive model based on risk factors was established, and the area under the receiver operating characteristic curve (AUC) was calculated. Results: In the multivariate model, an initial diagnosis of compensated cirrhosis and post-SVR albumin reductions of 1 g/L were associated with 21.7-fold (95% CI, 4.2 to 112.3; p< 0.001) and 1.3-fold (95% CI, 1.1 to 1.7; p=0.004) increases in the risk of HCC after SVR, respectively. A predictive model based on an initial diagnosis of compensated cirrhosis (yes, +1; no, 0) and post- SVR albumin ≤36.0 g/L (yes, +1; not, 0) predicted the occurrence of HCC after SVR with a cutoff value of >0, an AUC of 0.880, a sensitivity of 0.833, a specificity of 0.896, and a negative predictive value of 0.956. Conclusions: An initial diagnosis of compensated cirrhosis combined with a post-SVR albumin value of ≤36.0 g/L predicts the occurrence of HCC after SVR in patients with CHC. (Gut Liver 2016;10:955-961)

Reduction of the contact resistance in copper phthalocyanine thin film transistor with UV/ozone treated Au electrodes

Jun Li,Liang Zhang,Xiao-Wen Zhang,Hao Zhang,Xue-Yin Jiang,Dong-bin Yu,Wen-Qing Zhu,Zhi-Lin Zhang 한국물리학회 2010 Current Applied Physics Vol.10 No.5

Bottom-contact (BC) copper phthalocyanine (CuPc) thin film transistor with UV/ozone treated Au as a source/drain electrode was fabricated and the contact resistance was estimated from the transmission line method (TLM). Comparing the properties of OTFT with untreated Au electrode, the performance of the BC CuPc-TFT with the UV/ozone treated Au electrodes was significantly improved: saturation mobility increased from 4.69 × 10−3 to 2.37 × 10−2 ㎠/V s, threshold voltage reduced from −29.1 to −6.4 V, and threshold swing varied from 5.08 to 2.25 V/decade. The contact resistance of the device with UV/ozone treated Au electrodes was nearly 20 times smaller than that of the device with untreated Au electrodes at the gate voltage of −20 V. This result indicated that using the UV/ozone treated Au electrode is an effective method to reduce the contact resistance. The present BC configuration with UV/ozone treated Au electrodes could be a significant step towards the commercialization of OTFT technology.

First-principles study on the electronic structure and optical properties of La0.75Sr0.25MnO3-σ materials with oxygen vacancies defects

Jun Jiang,Qing-Ming Chen,Xiang Liu 한국물리학회 2018 Current Applied Physics Vol.18 No.2

The electronic structure and optical properties of La0.75Sr0.25MnO3-σ (LSMO3-σ) materials with 1 × 1 × 4 orthorhombic perovskite structure were performed by first-principles calculation. The structural changing of LSMO3 (ideal structure, σ = 0) was not obvious under generalized gradient approximation (GGA) and GGA + U arithmetic. On the contrary, the structural changing of LSMO3-σ (σ = 0.25, with oxygen vacancies defects in the z = 0, c/8, c/6, c/4, and c/2) with GGA + U were more obvious than the result of ideal. This structural distortion induced distinct changing in density of states (DOS) for LSMO3-σ materials. Oxygen vacancy defects caused a shift of the total density of states (TDOS) features toward low binding energies and LSMO3-σ keep half-metal properties as well as LSMO3 ideal structure. In addition, the hybridization between the Mn-eg and O-2p orbital was weakened and the partial density of states (PDOS) of Mn indicated a strong d-d orbital interaction. By the result of oxygen vacancy formation energy, oxygen vacancy defects can be more easily formed in La-O layers (z = 0 and c/6) to compare with other layers (z = c/8, c/4 and c/2). The calculation result of optical properties suggested that the ideal LSMO could be produced strong absorption in the range of ultraviolet and visible light, while the LSMO3-σ with oxygen vacancies defects were presented weak absorption in the range of visible light.

Genetic Polymorphism of GSTP1: Prediction of Clinical Outcome to Oxaliplatin/5-FU-based Chemotherapy in Advanced Gastric Cancer

Qing-Fang Li,Ru-Yong Yao,Ke-wei Liu,Hong-Ying Lv,Tao Jiang,Jun Liang 대한의학회 2010 Journal of Korean medical science Vol.25 No.6

The aim of this study was to evaluate the predictive value of the polymorphism Glutathione S-transferase P1 (GSTP1) Ile105Val on oxaliplatin/5-FU-based chemotherapy in advanced gastric cancer. Patients with advanced gastric cancer accepted oxaliplatin/5-FU-based chemotherapy as first-line chemotherapy were investigated. GSTP1 Ile105Val polymorphism was detected by TaqMan-MGB probe allelic discrimination method. Response to treatment was assessed by disease controlled rate. Time to progression, overall survival and toxicities were recorded. Final patient outcomes were as follows: the allele frequencies of GSTP1 were 105Ile/105Ile 52%, 105Ile/105Val 41% and 105Val/105Val 7%. For patients with 105Ile/105Ile and those with at least one 105Val allele, disease control rate was 39% and 71% (P=0.026), respectively;median time to progression was 4.0 and 7.0 months (P=0.002); median overall survival time was 7.0 and 9.5 months (P=0.002). Neurological toxicity was more frequently occurred in patients with two 105Ile alleles (P=0.005). In conclusion, patients with at least one 105Val allele have better prognosis and response to oxaliplatin/5-FUbased regimen as first-line treatment for patients with advanced gastric cancer.

SiOx interlayer to enhance the performance of InGaZnO-TFT with AlOx gate insulator

Jun Li,Fan Zhou,Hua-Ping Lin,Wen-Qing Zhu,Jianhua Zhang,Xue-Yin Jiang,Zhi-Lin Zhang 한국물리학회 2012 Current Applied Physics Vol.12 No.5

We have fabricated indium-gallium-zinc (IGZO) thin film transistor (TFT) using SiOx interlayer modified aluminum oxide (AlOx) film as the gate insulator and investigated their electrical characteristics and bias voltage stress. Compared with IGZO-TFT with AlOx insulator, IGZO-TFT with AlOx/SiOx insulator shows superior performance and better bias stability. The saturation mobility increases from 5.6 cm2/V s to 7.8 cm2/V s, the threshold voltage downshifts from 9.5 V to 3.3 V, and the contact resistance reduces from 132 Ucm to 91 Ucm. The performance improvement is attributed to the following reasons: (1) the introduction of SiOx interlayer improves the insulator surface properties and leads to the high quality IGZO film and low trap density of IGZO/insulator interface. (2) The better interface between the channel and S/D electrodes is favorable to reduce the contact resistance of IGZO-TFT.