K-doping effect of the superconductivity in K2xFeTe1-xSx (0.07 ≤ x ≤ 0.3)

Cheng Cheng,Zhenjie Feng,Qing Li,Tao Li,Qiang Hou,Fei Chen,Zhongmin Ou,Jun-Yi Ge,Shixun Cao,Jincang Zhang 한국물리학회 2019 Current Applied Physics Vol.19 No.4

Bulk samples of K doping K2xFeTe1-xSx with x=0.07, 0.1, 0.2, 0.3 are successfully prepared by using easy-to-use stable compound K2S as the reactant. The lattice constant calculated from X-ray diffraction patterns indicate that K ions enter the Fe-Te-S layers. K doping is beneficial enhance the superconductivity transition temperature from the R-T curves. The apparent diamagnetic signal is observed in M-T curves when the content of K is smaller than 0.1. However, differential curves (dM/dT) in K-rich samples appear sharp slope mutations, which means that the Meissner effect signal is covered by the increased excess ferromagnetic ions. The number of excess Fe magnetic ions is proportional to K content, which may play an important role in determining the superconductivity.

Quantized _{H ∞} filtering for switched linear parameter-varying systems with sojourn probabilities and unreliable communication channels

Cheng, Jun,Park, Ju H.,Cao, Jinde,Zhang, Dian Elsevier 2018 Information sciences Vol.466 No.-

<P><B>Abstract</B></P> <P>This paper addresses the problem of quantized <SUB> H ∞ </SUB> filtering for switched linear parameter-varying systems with both sojourn probabilities and unreliable communication channels. A more general model is developed, where both the mode-dependent logarithmic quantizer and channel noise are taken into consideration. With the sojourn probability-based switching law and parameterized Lyapunov functional, sufficient criteria promising stochastic stability of switched linear parameter- varying systems are derived. Finally, the results of the simulation show the effectiveness and feasibility of the proposed method.</P>

Protectin DX increases alveolar fluid clearance in rats with lipopolysaccharideinduced acute lung injury

Xiao-Jun Zhuo,Yu Hao,Fei Cao,Song-Fan Yan,Hui Li,Qian Wang,Bi-Huan Cheng,Bin-Yu Ying,Bin-Yu Ying,Sheng-Wei Jin 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Acute respiratory distress syndrome is a life-threatening critical syndrome resulting largely from the accumulation of and the inability to clear pulmonary edema. Protectin DX, an endogenously produced lipid mediator, is believed to exert anti-inflammatory and pro-resolution effects. Protectin DX (5 μg/kg) was injected i.v. 8 h after LPS (14 mg/kg) administration, and alveolar fluid clearance was measured in live rats (n = 8). In primary rat ATII epithelial cells, protectin DX (3.605 × 10−3 mg/l) was added to the culture medium with LPS for 6 h. Protectin DX improved alveolar fluid clearance (9.65 ± 1.60 vs. 15.85 ± 1.49, p < 0.0001) and decreased pulmonary edema and lung injury in LPSinduced lung injury in rats. Protectin DX markedly regulated alveolar fluid clearance by upregulating sodium channel and Na, K-ATPase protein expression levels in vivo and in vitro. Protectin DX also increased the activity of Na, K-ATPase and upregulated P-Akt via inhibiting Nedd4–2 in vivo. In addition, protectin DX enhanced the subcellular distribution of sodium channels and Na, K-ATPase, which were specifically localized to the apical and basal membranes of primary rat ATII cells. Furthermore, BOC-2, Rp-cAMP, and LY294002 blocked the increased alveolar fluid clearance in response to protectin DX. Protectin DX stimulates alveolar fluid clearance through a mechanism partly dependent on alveolar epithelial sodium channel and Na, K-ATPase activation via the ALX/PI3K/Nedd4–2 signaling pathway.

Robust _{H ∞} control for nonhomogeneous Markovian jump systems subject to quantized feedback and probabilistic measurements

Zhang, Dian,Cheng, Jun,Park, Ju H.,Cao, Jinde Elsevier 2018 Journal of the Franklin Institute Vol.355 No.15

<P><B>Abstract</B></P> <P>The present paper considers the issue of robust <SUB> H ∞ </SUB> control for nonhomogeneous Markovian jump systems (NMJSs) subject to quantized feedback and probabilistic measurements. The time-varying property of the transition probability (TP) is modeled by polytope. The quantized control law, which makes full use of the information of communication limitation of channel resources, is developed. The probabilistic measurements are utilized to model the unideal information transmission. A novel sufficient condition is achieved in the form of linear matrix inequalities (LMIs). Finally, numerical examples are adopted to demonstrate the feasibility and effectiveness of the presented theoretical results.</P>

Enhanced CO methanation over Ni-based catalyst using a support with 3D-mesopores

Hong-Xia Cao,Jun Zhang,Xiang-Kun Ren,Cheng-Long Guo 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.9

Ni-based catalysts supported on a support with 3D-mesopores, including Ni/KIT-6(EG), Ni/KIT-6(PS) and Ni/KIT-6(DS), were prepared by adding ethylene glycol, direct synthesis and post synthesis methods, respectively, and their catalytic properties were investigated for CO methanation as one of the core technologies of synthetic natural gas production in a continuous flow fixed-bed reactor. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), hydrogen temperature-programmed reduction (H2-TPR), hydrogen temperature-programmed desorption (H2-TPD) and thermal gravimetric analysis (TGA), respectively. The results showed that Ni/KIT-6(EG) exhibited the best catalytic performance with CO conversion of almost 100% and CH4 yield of 75% at 450 oC, atmospheric pressure and 60,000 mL/g/h due to the higher dispersion of Ni species, stronger reducibility of NiO and formation of smaller Ni nanoparticles fixed into 3D-mesopores, indicating that adding ethylene glycol was effective to improve catalytic performance of Ni-based catalyst for CO methanation. Moreover, compared with Ni/Al2O3(EG) prepared using Al2O3 as a support, Ni/KIT- 6(EG) showed better catalytic performance owing to the higher specific surface area, stronger reducibility of NiO and confinement effect of 3D-mesopores promoting to produce more active sites. After 60h lifetime test of Ni/KIT-6(EG) at 500 oC, atmospheric pressure and 60,000mL/g/h, 3D-mesopores were still maintained and no obvious agglomeration of Ni nanoparticles was observed, meaning that Ni species were still well dispersed into 3D-mesopores. As a consequence, Ni/KIT-6(EG) exhibited superior catalytic performance and stability, which makes it a promising candidate for CO methanation.

Spectral Research on an AlGaAs Epitaxial Material for a Terahertz Quantum-cascade Laser

Zhi-Yong Tan,Jun-Cheng Cao 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.8

The spectral properties of a series of AlGaAs epitaxial films were studied by using a Fourier transform infrared spectrometer with an 80-degree grazing incidence reflection unit. The AlAslike transversal optical phonon was obviously observed in the spectra, but the longitudinal optical phonon was obscured in the transmission spectra. The variation curves for the transversal optical phonon energy were acquired from the two kinds of spectra and were compared with each other and with the early results. A comparison of the results show that the grazing incidence reflection spectrum is better in reflecting the AlAs-like phonon energy of an AlGaAs epitaxial film and could be a supplementary means in the characterization of the material for a terahertz quantum-cascade laser.

Immunoprofiling of the Tryptophan-Rich Antigen Family in <i>Plasmodium vivax</i>

Wang, Bo,Lu, Feng,Cheng, Yang,Chen, Jun-Hu,Jeon, Hye-Yoon,Ha, Kwon-Soo,Cao, Jun,Nyunt, Myat Htut,Han, Jin-Hee,Lee, Seong-Kyun,Kyaw, Myat Phone,Sattabongkot, Jetsumon,Takashima, Eizo,Tsuboi, Takafumi,H American Society for Microbiology 2015 Infection and immunity Vol.83 No.8

<P>Tryptophan-rich antigens (TRAgs) are an antigen family that has been identified in human and rodent malaria parasites. TRAgs have been proposed as candidate antigens for potential vaccines. The <I>Plasmodium vivax</I> TRAg (PvTRAg) family includes 36 members. Each PvTRAg contains a tryptophan-rich (TR) domain in the C-terminal region. In this study, we recombinantly expressed all 36 PvTRAgs using a cell-free expression system, and, for the first time, profiled the IgG antibody responses against all PvTRAgs in the sera from 96 vivax malaria patients and 40 healthy individuals using protein microarray technology. The mean seropositive rate for all PvTRAgs was 60.3%. Among them, nine PvTRAgs were newly identified in this study and showed a seropositive rate of >50%. Five of them, PvTRAg_13, PvTRAg_15, PvTRAg_16, PvTRAg_26, and PvTRAg_29, produced higher levels of IgG antibody, even in low-endemicity countries. In addition, the results of an immunofluorescence analysis suggest that PvTRAgs are, at least in part, associated with caveola-vesicle complexes, a unique structure of <I>P. vivax</I>-infected erythrocytes. The mechanism of formation and the function of these abundant membrane structures are not known. Further investigation aimed at determining the functions of these proteins would lead to a better understanding of the blood-stage biology of <I>P. vivax</I>.</P>

Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis of Cerebral Venous Thrombosis : A Meta-Analysis

Lv, Bin,Jing, Feng,Tian, Cheng-lin,Liu, Jian-chao,Wang, Jun,Cao, Xiang-yu,Liu, Xin-feng,Yu, Sheng-yuan The Korean Neurosurgical Society 2021 Journal of Korean neurosurgical society Vol.64 No.3

Objective : A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not well-understood. This study evaluates the effectiveness of DWI in the diagnosis of CVT. Methods : Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue. Results : Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference-0.33×10-3 ㎟/s [95% CI, -0.44 to -0.23]; p<0.00001). Conclusion : DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

Triptolide Inhibits Proliferation and Induces Apoptosis of Human Melanoma A375 Cells

Tao, Yue,Zhang, Meng-Li,Ma, Peng-Cheng,Sun, Jian-Fang,Zhou, Wu-Qing,Cao, Yu-Ping,Li, Ling-Jun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Triptolide, a diterpenoid obtained from Tripteryglum wilfordii Hook.f, has attracted interest for its antitumor activities against human tumor cell lines in recent years. This report focuses on anti-proliferative and pro-apoptotic activities in human melanoma A375 cells assessed by CCK8 assay, Hoechst 33258 staining and flow cytometry. In addition, triptolide-induced arrest in the S phase was also observed. Caspase assays showed the apoptosis induced by triptolide was caspase-dependent and probably through intrinsic apoptotic pathways. Furthermore, expression of NF-${\kappa}B$ (p65) and its downstream factors such as Bcl-2, Bcl-$X_L$ was down-regulated. Taken together, the data indicate that triptolide inhibits A375 cells proliferation and induces apoptosis by a caspase-dependent pathway and through a NF-${\kappa}B$-mediated mechanism.

Dephasing Effect on the Carrier-light Interaction in Terahertz Quantum Cascade Lasers

Feng Wang,Xu Guang Guo,Jun Cheng Cao 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.41

We study the dephasing effect on the carrier-light interaction in terahertz quantum cascade lasers by using a rate-equation method including the optical field. The time evolution of the gain coefficient and the stimulated radiation rate are shown. We theoretically provide an ultrafast microscopic process for the conversion of a working terahertz quantum cascade laser from an unsaturated to a saturated state.