Separation of arenols from a low-temperature coal tar by liquid-liquid extraction

Hua-Shuai Gao,Zhi-Min Zong,Zheng Yang,Dao-Guang Teng,Xiu-Hua Sun,Li Yan,Xian-Yong Wei,Qing-Jie Guo,Tian-Sheng Zhao,Hong-Cun Bai 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.5

Low-temperature coal tar (LTCT) is a sticky liquid mixture produced mainly from coal pyrolysis, which contains various value-added chemicals (VACs). Liquid-liquid extraction is considered as one of the green and effective ways to explore the organic composition and separate the VACs from LTCT. Herein, petroleum ether, methanol, and carbon disulfide were used to extract arenols from a LTCT. As a result, the relative content and absolute content of arenols extracted from the LTCT are ca. 96.3% and 85.9%, respectively. Among them, p-cresol is predominant, accounting for 22.2%. The isolated contents of arenols are up to 84.6%. Moreover, a kilogram-scale operation was carried out under the same conditions, which offers a potential application in industrial production.

WAVEFRONT SOLUTIONS IN THE DIFFUSIVE NICHOLSON’S BLOWFLIES EQUATION WITH NONLOCAL DELAY

Cun-Hua Zhang 한국전산응용수학회 2010 Journal of applied mathematics & informatics Vol.28 No.1

In the present article we consider the diffusive Nicholson’s blowflies equation with nonlocal delay incorporated into an integral convolution over all the past time and the whole infinite spatial domain R. When the kernel function takes a special function, we construct a pair of lower and upper solutions of the corresponding travelling wave equation and obtain the existence of travelling fronts according to the existence result of travelling wave front solutions for reaction diffusion systems with nonlocal delays developed byWang, Li and Ruan (J. Differential Equations,222(2006), 185-232).

Analytic Solution for an Eaton Lens for Rotating 90°

Cun-Hua Zhao 한국광학회 2020 Current Optics and Photonics Vol.4 No.4

The Eaton lens, with spherical symmetry to its refractive index, was described by Eaton in 1952 and was found recently in the design of an invisible sphere for cloaking. In this paper, an Eaton lens for rotating 90° was designed using Luneburg theory, by which we found it was a fourth-order equation in the refractive index . Therefore, the refractive index  has four roots. The equation in  was solved and studied using mathematical technology. The unsuitable complex roots of the equation should be dropped; consequently, only one of the four roots remained. To verify the refractive-index profile, the only root was solved for, before a simulation using finite-element analysis (FEA) was performed. The simulation showed that all rays will bend 90° to the right. The result of the simulation is identical to our expectation. This treatment provides a possible method for rotating light at many other angles.

Interval oscillation criteria for a second order nonlinear differential equation

Cun-Hua Zhang 한국전산응용수학회 2009 Journal of applied mathematics & informatics Vol.27 No.5

This paper is concerned with the interval oscillation of the second order nonlinear ordinary differential equation (r (t) |y' (t)α−1 y'(t)' + p (t) |y' (t)α−1 y'(t)+q (t) f (y (t)) g (y'(t)) = 0. By constructing a generalized Riccati transformation and using the method of averaging techniques, we establish some interval oscillation criteria when f(y) is not differetiable but satisfies the condition<수식> μ0 > 0 for y ≠ 0. This paper is concerned with the interval oscillation of the second order nonlinear ordinary differential equation (r (t) |y' (t)α−1 y'(t)' + p (t) |y' (t)α−1 y'(t)+q (t) f (y (t)) g (y'(t)) = 0. By constructing a generalized Riccati transformation and using the method of averaging techniques, we establish some interval oscillation criteria when f(y) is not differetiable but satisfies the condition<수식> μ0 > 0 for y ≠ 0.

WAVEFRONT SOLUTIONS IN THE DIFFUSIVE NICHOLSON'S BLOWFLIES EQUATION WITH NONLOCAL DELAY

Zhang, Cun-Hua The Korean Society for Computational and Applied M 2010 Journal of applied mathematics & informatics Vol.28 No.1

In the present article we consider the diffusive Nicholson's blowflies equation with nonlocal delay incorporated into an integral convolution over all the past time and the whole infinite spatial domain $\mathbb{R}$. When the kernel function takes a special function, we construct a pair of lower and upper solutions of the corresponding travelling wave equation and obtain the existence of travelling fronts according to the existence result of travelling wave front solutions for reaction diffusion systems with nonlocal delays developed by Wang, Li and Ruan (J. Differential Equations, 222(2006), 185-232).

INTERVAL OSCILLATION CRITERIA FOR A SECOND ORDER NONLINEAR DIFFERENTIAL EQUATION

Zhang, Cun-Hua The Korean Society for Computational and Applied M 2009 Journal of applied mathematics & informatics Vol.27 No.5

This paper is concerned with the interval oscillation of the second order nonlinear ordinary differential equation (r(t)|y'(t)|$^{{\alpha}-1}$ y'(t))'+p(t)|y'(t)|$^{{\alpha}-1}$ y'(t)+q(t)f(y(t))g(y'(t))=0. By constructing ageneralized Riccati transformation and using the method of averaging techniques, we establish some interval oscillation criteria when f(y) is not differetiable but satisfies the condition $\frac{f(y)}{|y|^{{\alpha}-1}y}$ ${\geq}{\mu}_0$ > 0 for $y{\neq}0$.

Trans-Membrane Transport of n-Octadecane by Pseudomonas sp. DG17

Fei Hua,Hong Qi Wang,Yi Li,Yi Cun Zhao 한국미생물학회 2013 The journal of microbiology Vol.51 No.6

The trans-membrane transport of hydrocarbons is an important and complex aspect of the process of biodegradation of hydrocarbons by microorganisms. The mechanism of transport of 14C n-octadecane by Pseudomonas sp. DG17,an alkane-degrading bacterium, was studied by the addition of ATP inhibitors and different substrate concentrations. When the concentration of n-octadecane was higher than 4.54 μmol/L, the transport of 14C n-octadecane was driven by a facilitated passive mechanism following the intra/extra substrate concentration gradient. However, when the cells were grown with a low concentration of the substrate, the cellular accumulation of n-octadecane, an energy-dependent process, was dramatically decreased by the presence of ATP inhibitors, and n-octadecane accumulation continually increased against its concentration gradient. Furthermore, the presence of non-labeled alkanes blocked 14C n-octadecane transport only in the induced cells, and the trans-membrane transport of n-octadecane was specific with an apparent dissociation constant Kt of 11.27 μmol/L and Vmax of 0.96μmol/min/mg protein. The results indicated that the transmembrane transport of n-octadecane by Pseudomonas sp. DG17 was related to the substrate concentration and ATP.

Expression of Fas/FasL in CD8⁺ T and CD3⁺ Foxp3⁺ Treg Cells - Relationship with Apoptosis of Circulating CD8⁺ T Cells in Hepatocellular Carcinoma Patients

Guo, Cun-Li,Yang, Xiu-Hua,Cheng, Wen,Xu, Yi,Li, Jie-Bing,Sun, Yi-Xin,Bi, Yu-Mei,Zhang, Lei,Wang, Qiu-Cheng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Aims: Dysfunction of the host immune system in cancer patients can be due to a number of factors, including lymphocyte apoptosis. Several studies showed that $Foxp3^+T$ cells take part in inducing this process by expressing FasL in tumor patients. However, the relationship between apoptosis, $CD8^+T$ cells and $Foxp3^+T$ cells in HCC patients is still unclear. The present study was designed to investigate the correlation between apoptosis levels and Fas/FasL expression in $CD8^+T$ lymphocytes and $Foxp3^+T$ cells in patients with HCC. Methods: $CD8^+T$ cells and $CD3^+Foxp3^+T$ cells were tested from peripheral blood of HCC patients and normal controls and subjected to multicolor flow cytometry. The expression of an apoptosis marker (annexin V) and the death receptor Fas in $CD8^+T$ cells and FasL in $CD3^+Foxp3^+T$ cells were evaluated. Serum TGF-${\beta}1$ levels in patients with HCC were measured by enzyme-linked immunosorbent assay. The relationship between apoptosis and Fas expression, as well as FasL expression in $CD3^+Foxp3^+T$ cells was then evaluated. Results: The frequency of $CD8^+T$ cells binding annexin V and Fas expression in $CD8^+T$ cells, were all higher in HCC patients than normal controls and the proportion of apoptotic $CD8^+T$ cells correlated with their Fas expression. Serum TGF-${\beta}1$ levels correlated inversely with $CD3^+Foxp3^+T$ cells. Conclusions: Fas/FasL interactions might lead to excessive turnover of $CD8^+T$ cells and reduce anti-tumor immune responses in patients with HCC. Further investigations of apoptosis induction in $Fas^+CD8^+T$ cells in vitro are required.

Associations Between Infiltrating Lymphocyte Subsets and Hepatocellular Carcinoma

Guo, Cun-Li,Yang, Hai-Chao,Yang, Xiu-Hua,Cheng, Wen,Dong, Tian-Xiu,Zhu, Wen-Jing,Xu, Zheng,Zhao, Liang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Aims: We aimed to analyze the phenotype of tumor-infiltrating lymphocytes (TILs) and non-tumor infiltrating lymphocytes (NILs) in HCC and non-tumor tissues, and evaluate relationships between changes in these cells and the prognosis of HCC. Methods: Lymphocytes were isolated from HCC and corresponding non-tumor tissues and tested by flow cytometry. For comparison, clinical parameters were analyzed. Results: Compared with the non-tumor tissue, tumor tissue had a lower intensity of NK, NKT andCD8+T cell infiltration. TILs had higher intensity of CD4+CD25+Foxp3+regulatory T cell (Treg cells) infiltration compared with that in NILs. The prevalence of Treg cells was associated with fewer CD8 + T lymphocytes in the HCC immune microenvironment. The frequencies of NK cells and CD8+T cells in TILs of HCC patients with metastasis less than 12 months were lower than those without metastasis. However, the frequency of Treg cells was higher than those without metastasis. Conclusion: These results suggest that the frequencies of CD8+T, NK and NKT cells as well as Treg cells in the tumor tissue of HCC are significantly associated with patient survival, and could be applied as predictive indicators for HCC prognosis.

Stability of positive steady-state solutions in a delayed Lotka-Volterra diffusion system

Xiang-Ping Yan,Cun-Hua Zhang 대한수학회 2012 대한수학회지 Vol.49 No.4

This paper considers the stability of positive steady-state so-lutions bifurcating from the trivial solution in a delayed Lotka-Volterra two-species predator-prey diffusion system with a discrete delay and sub-ject to the homogeneous Dirichlet boundary conditions on a general boun-ded open spatial domain with smooth boundary. The existence, unique-ness and asymptotic expressions of small positive steady-sate solutions bifurcating from the trivial solution are given by using the implicit func-tion theorem. By regarding the time delay as the bifurcation parameter and analyzing in detail the eigenvalue problems of system at the positive steady-state solutions, the asymptotic stability of bifurcating steady-state solutions is studied. It is demonstrated that the bifurcating steady-state solutions are asymptotically stable when the delay is less than a certain critical value and is unstable when the delay is greater than this critical value and the system under consideration can undergo a Hopf bifurcation at the bifurcating steady-state solutions when the delay crosses through a sequence of critical values.