GLOBAL ASYMPTOTIC STABILITY FOR A DIFFUSION LOTKA-VOLTERRA COMPETITION SYSTEM WITH TIME DELAYS

Jia-Fang Zhang,Ping-An Zhang 대한수학회 2012 대한수학회보 Vol.49 No.6

A type of delayed Lotka-Volterra competition reaction-diffu\-sion system is considered. By constructing a new Lyapunov function, we prove that the unique positive steady-state solution is globally asymptotically stable when interspecies competition is weaker than intraspecies competition. Moreover, we show that the stability property does not depend on the diffusion coefficients and time delays.

Synthesis of Chiral Bisacylphosphine Oxides and Their Application as Initiators in Helix-Sense-Selective Photopolymerization

Jia-An Zhang,Nian-Fa Yang,Li-Wen Yang,Shi Wu,Ye-Hui Chen,Jin Zhang 한국고분자학회 2013 Macromolecular Research Vol.21 No.6

Three new chiral bisacylphosphine oxides, (-)-bis(menthylformyl)phenylphosphine oxide (1a), (+)-bis(2,4,6-trimethylbenzoyl)menthylphosphine oxide (2a), and (-)-bis(menthylformyl)menthylphosphine oxide (3a),were synthesized using menthol as a chiral source. The synthesized new chiral bisacylphosphine oxides were used as photoinitiators for the polymerization of 1-phenyldibenzosuberyl methacrylate (PDBSMA). The polymerization initiated by chiral bisacylphosphine oxides under UV light irradiation is helix-sense-selective. Among the three prepared chiral bisacylphosphine oxides, the helix-sense-selectivity of bis(menthylformyl)menthylphosphine oxide is highest. The highest specific rotation of poly(1-phenyldibenzosuberyl methacrylate) at 365 nm is +416. The feed molar ratio of monomer to chiral bisacylphosphine oxide and the polymerization temperature have an influence on the helix-sense-selectivity. The lower the feed molar ratio of monomer to chiral bisacylphosphine oxide, the better the helix-sense-selectivity is. The increase of polymerization temperature is propitious to increase the helix-senseselectivity of the photopolymerization.

GLOBAL ASYMPTOTIC STABILITY FOR A DIFFUSION LOTKA-VOLTERRA COMPETITION SYSTEM WITH TIME DELAYS

Zhang, Jia-Fang,Zhang, Ping-An Korean Mathematical Society 2012 대한수학회보 Vol.49 No.6

A type of delayed Lotka-Volterra competition reaction-diffusion system is considered. By constructing a new Lyapunov function, we prove that the unique positive steady-state solution is globally asymptotically stable when interspecies competition is weaker than intraspecies competition. Moreover, we show that the stability property does not depend on the diffusion coefficients and time delays.

Cloning, Expression, and Characterization of Serine Protease from Thermophilic Fungus Thermoascus aurantiacus var. levisporus

An-Na Li,Chen Xie,Jie Zhang,Jia Zhang,Duo-Chuan Li 한국미생물학회 2011 The journal of microbiology Vol.49 No.1

The serine protease gene from a thermophilic fungus Thermoascus aurantiacus var. levisporus, was cloned,sequenced, and expressed in Pichia pastoris and the recombinant protein was characterized. The full-length cDNA of 2,592 bp contains an ORF of 1,482 bp encoding 494 amino acids. Sequence analysis of the deduced amino acid sequence revealed high homology with subtilisin serine proteases. The putative enzyme contained catalytic domain with active sites formed by three residues of Asp183, His215, and Ser384. The molecular mass of the recombinant enzyme was estimated to be 59.1 kDa after overexpression in P. pastoris. The activity of recombinant protein was 115.58 U/mg. The protease exhibited its maximal activity at 50°C and pH 8.0 and kept thermostable at 60°C, and retained 60% activity after 60 min at 70°C. The protease activity was found to be inhibited by PMSF, but not by DTT or EDTA. The enzyme has broad substrate specificity such as gelatin, casein and pure milk, and exhibiting highest activity towards casein.

Genetic parameter estimation for reproductive traits in QingYu pigs and comparison of carcass and meat quality traits to Berkshire×QingYu crossbred pigs

Luo Jia,Yang Yiting,Liao Kun,Liu Bin,Chen Ying,Shen Linyuan,Chen Lei,Jiang An’an,Liu Yihui,Li Qiang,Wang Jinyong,Li Xuewei,Zhang Shunhua,Zhu Li 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.8

Objective: The QingYu pig is well known for its excellent meat quality attributes in Sichuan province, China. In order to improve its production efficiency, the determination of genetic factors contributing to quantifiable economic traits of livestock is important. Moreover, the cross-breeding of QingYu pigs with western breeds possessing strong growth attributes is an efficient way to improve the performance of this breed. Methods: Here, the genetic parameters of several important reproductive traits of QingYu pigs were estimated, include total number born (TNB), number born alive, litter birth weight, individual birth weight, number of piglets weaned, litter weaning weight, and individual weaning weight. The data was analyzed using the ASReml 3.0 software (NSW Inc., Sydney, Australia). Furthermore, the effects of crossing Berkshire with QingYu (BQ) pigs on carcass and meat quality traits, as well as the effects of slaughter weight on carcass and meat quality of BQ were characterized. Results: QingYu pigs exhibited superior reproductive traits. The TNB available to QingYu pigs was more than 8 per parity. The observed repeatability of the reproductive traits of the QingYu pigs was between 0.10 and 0.23. The significantly correlated genetic and phenotypic of reproduction traits were consistent. Interestingly, the BQ pigs exhibited improved carcass quality, with a significant increase in loin muscle area, lean percentage and reduction in sebum percentage. As a result, BQ had higher L45min, lower cooking scores, and lower drip loss. In addition, the loin muscle area, body length, and sebum percentage were significantly higher in 90 and 100 kg animals. Cooking loss showed a significant increase at 80 kg, and marbling increased significantly from 90 kg. Conclusion: The results of this study suggest that QingYu pigs exhibit excellent reproductive properties and heritability of these traits. Crossing with Berkshire is an efficient strategy to improve the carcass and meat quality of QingYu pigs for commercial operations. Furthermore, it appears as though the optimal slaughter weight of BQ pigs is at approximately 90 kg.

Identification of a Cancer Stem-like Population in the Lewis Lung Cancer Cell Line

Zhang, An-Mei,Fan, Ye,Yao, Quan,Ma, Hu,Lin, Sheng,Zhu, Cong-Hui,Wang, Xin-Xin,Liu, Jia,Zhu, Bo,Sun, Jian-Guo,Chen, Zheng-Tang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.

The utilization and industrialization of insect resources in China

Chuan-Xi Zhang,Xu-Dong TANG,Jia-An CHENG 한국곤충학회 2008 Entomological Research Vol.38 No.-

Insecta is the biggest group of animals on earth. The insects are thought to be one of the biggest biological resources that have not been fully exploited by humans. China is one of the earliest countries to exploit insect resources in the world and has been the top producer for over one thousand years of many insect-related industrial products, such as silk, insect wax and Chinese gallnuts. The exploitation and industrialization of insect resources in China is generally classified into four different levels. The first level is the direct utilization of insect bodies and their secretions, the history of which can be traced back for thousands of years. This level includes the culture and utilization of the silkworm Bombyx mori, the Chinese honeybee Apis cerana cerana, the Chinese white-wax scale Ericerus pela, the Chinese gall aphid Schlechtendalia chinensis, and the lac insects Kerria spp. Additionally, numerous other insects are typically used for Chinese traditional medicines and food, such as Eupolyphaga sinensis, Opisthoplatia orientalis, Aspongopus chinensis, Martianus dermestoides, Polyrhachis vicina, Hepialus spp, Vespa, Hydrillodes repugnalis, and Tenebrio molitor. Pollinators (Megachile rotundata, Osmia cornifrons, O. excavata) and ornamental insects like butterflies, katydids Gampsocleis grafiosa, and fighting crickets Scapsipedes micado are also among the insects included in this level. Accordingly, a related industry is insect-breeding, including sericulture and apiculture, which lays the basis for all insect industrialization. The second level is the utilization of insects as enemies of pests and insect pathogens for biological control. The enemy insects, including the egg parasites tricogramma Trichogramma spp, the seven spotted lady beetle Coccinella septempunctata, the Chinese green lacewing Chrysopa sinica, and Anastatus sp. could be produced in large scale. The insect pathogens that have been extensively used for commercial biocontrol in China include Helicoverpa armigera Nucleopolyhedrovirus (HaSNPV), Ectropis oblique Nucleopolyhedrovirus (EcobNPV), Spodoptera exigua multicapsid nucleopolyhedrovirus (SeMNPV), Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV), Plutella xylostella Granulosis (PxGV), Pieris rapae granulosis (PiraGV), and Bacillus thuringiensis (Bt). Related industries include the biopesticide industry and the enemy insect production industry. The third level of utilization is the extraction and synthesis of insect materials with diverse bioactivities. Some insect pheromones and hormones extracted from insect bodies or chemically synthesized have been used for insect pest control and for regulating the silkworm breeding. Toxins from honeybees and wasps have been used in medicine. Some insect materials from the larvae of honeybees, silkworms, tasar silkworms, and houseflies have been developed into health products. The fourth level is using the insects as bioreactors to produce peptides for medical and veterinary uses. Hundreds of foreign genes have been successfully expressed in the insect cells and larvae. The hGM-CSF expressed in silkworm pupae is commercially available. In this article, we review the culture and utilization of important industrial insects in China.

Application of Lobaplatin in Trans-catheter Arterial Chemoembolization for Primary Hepatic Carcinoma

Wang, Nan,Lv, Yin-Zhang,Xu, An-Hui,Huang, Yan-Rong,Peng, Ling,Li, Jia-Rui Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Objective: To explore the efficiency of single application of lobaplatin in tran-scatheter arterial chemoembolization (TACE) for patients with a primary hepatic carcinoma who were unable or unwilling to undergo surgery. Methods: 173 patients with primary hepatic carcinoma diagnosed by imaging or pathology were randomly divided into experimental and control groups and respectively treated with lobaplatin and pirarubicin hydrochloride as chemotherapeutic drugs for TACE. The amount of iodipin was regulated according to the tumor number and size, and then gelatin sponge or polyvinyl alcohol particles were applied for embolisms. The efficiency of treatment in the two groups was compared with reference to survival time and therapeutic response. Results: The experimental group (single lobaplatin as chemotherapy drug) was superior to control group (single pirarubicin hydrochloride as chemotherapy drug) in the aspects of survival time and therapeutic response, with statistical significance. Conclusions: Single lobaplatin can be as a chemotherapy drug in TACE and has better efficiency in the aspects of mean survival time and therapeutic response, deserving to be popularized in the clinic.

Antiproliferative Effects of Celecoxib in Hep-2 Cells through Telomerase Inhibition and Induction of Apoptosis

Zhao, Yong-Qiang,Feng, Hui-Wei,Jia, Tao,Chen, Xue-Mei,Zhang, Hui,Xu, An-Ting,Zhang, Hai-Ling,Fan, Xian-Liang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: To investigate the effect of celecoxib on telomerase activity and apoptosis in a human laryngeal squamous carcinoma cell line (Hep-2 cells). Materials and Methods: The growth inhibition rate of Hep-2 cells in vitro was measured by MTT assay, and apoptosis by TUNEL assay and flow cytometry (FCM). The TRAP-ELISA method was used to determine telomerase activity in Hep-2 cells. The mRNA expression of human telomerase RNA component(hTR), human telomerase reverse transcriptase (hTERT) and human telomerase-associated protein(hTEP1) was determined by RT-PCR assay. Expression of Bax and Bcl-2 proteins was assessed by Western blotting. Results: Celecoxib can inhibit proliferation and induce apoptosis in a dose- and time-dependent manner, repress telomerase activity, decrease hTERT mRNA and Bcl-2 protein expression and increase Bax protein expression, PGE2 had no effect on telomerase. Conclusions: Celecoxib had the antiproliferative and pro-apoptotic effect in Hep-2 cells. Apoptosis was accompanied by a decrease in telomerase activity which was directly correlated with hTERT mRNA and up-regulation of Bax/Bcl-2. Bcl-2 may thus play an important role in telomerase activity as well as apoptosis.

Effects of co-ion initial concentration ratio on removal of Pb2+ from aqueous solution by modified sugarcane bagasse

Jing Zhu,Jun-xia Yu,Jia-dong Chen,Jie-sen Zhang,Jia-qi Tang,Yuan-lai Xu,Yue-fei Zhang,Ru-an Chi 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.6

A modified sugarcane bagasse (SCB) fixed bed column was used to remove Pb2+ from aqueous solution. To determine the optimal condition for Pb2+ separation, Ca2+ was chosen as the model interfering ion, and effects of Ca2+ and Pb2+ initial concentration ratio (C0 Ca : C0 Pb) on the adsorption of Pb2+ were investigated. Results showed that adsorption amount ratio of Ca2+ and Pb2+ (qe Ca : qe Pb) had a good linear relationship with C0 Ca : C0 Pb. Mass ratio of Pb2+ absorbed on the modified SCB was higher than 95% at C0 Ca : C0 Pb<1.95, illustrating that Pb2+ could be selectively removed from aqueous solution. To verify that, simulated waste water containing co-ions of K+, Na+, Cd2+ and Ca2+ was treated, and results showed that the equilibrium amount of Pb2+, K+, Na+, Cd2+ and Ca2+ adsorbed was 134.14, 0.083, 0.058, 1.28, and 1.28mg g−1, respectively, demonstrating that the modified SCB could be used to remove Pb2+ from aqueous solution in the investigated range.