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Peng Z.,JiShou University | Shen Y.,JiShou University
Polymer - Plastics Technology and Engineering | Year: 2011

The hydrogel based on polyvinyl alcohol (PVA) and collagen was prepared by using a freeze-dried method. To evaluate the biological safety of the PVA/collagen hydrogel, which has a potential application in tissue substitute, cell viability and growth were assessed by using methylthiazoletetrazolium (MTT) assay and Alamar Blue assay; Micronucleus test was reckoned to identify genotoxicity, and sensitivity test was aimed to detect allergic response to skin. The results demonstrated that no significant cytotoxicity of the PVA/ collagen hydrogen against L929 mouse fibroblasts was observed. The micronucleus frequency of PVA/collagen was (2.5±0.79)‰, which showed no genotoxic effects either. In addition, there was no allergic response in long-term application. This study suggests that PVA/collagen hydrogen does not demonstrate any significant toxic effects to fibroblastic cells in-vitro and has the potential to be used as scaffolds in tissue engineering applications. © Taylor & Francis Group, LLC.

Peng Z.,JiShou University | Shen Y.,JiShou University
Polymer - Plastics Technology and Engineering | Year: 2011

Gelatin/chitosan hydrogels were prepared by using glutaraldehyde as crosslinker. The porous structure was confirmed by scanning electron microscope (SEM). Swelling ratios of the hydrogels with various ratio of gelatin to chitosan and crosslinker reagent dosage were studied in phosphate-buffered saline (PBS). In addition, in-vitro cytotoxicity was assessed via MTT assay with fibroblastic cell cultured in hydrogel extractions. It was found that by increasing glutaraldehyde dosage and chitosan content, the swelling ratio of the hydrogels decreased in buffer solutions. The MTT test showed that the gelatin/chitosan hydrogel clearly presented adequate cell viability, non-toxicity, and suitable properties. Therefore, these developed blends, based on gelatin and chitosan has broadened the number of choices of biomaterials to be potentially used in biomedical applications such as biomaterial, drug delivery vehicles and skin tissue engineering. © Taylor & Francis Group, LLC.

Peng Z.,JiShou University | Chen F.,South China University of Technology
International Journal of Polymeric Materials and Polymeric Biomaterials | Year: 2011

Hydrogels were synthesized from acetic acid lignin by chemical crosslinking with NCO-terminated polyurethane ionomers (IPUI). The swelling ratio of hydrogels increased with pH. The hydrogel prepared at the mass ratio of m AAL/mIPUI: 0.35:1 presented maximum swelling ratio in pH 6.8 buffer solutions. The results of thermogravimetric analysis demonstrated that the thermal stability of the hydrogels is improved by the introduction of lignin. The data of release experiments for ammonium sulfate suggests that the hydrogels can be used as coating materials to prepare a slow-release fertilizer. Copyright © 2011 Taylor & Francis Group, LLC.

The recently-proposed Zhang dynamics (ZD) has been proven to achieve success for solving the linear-equality constrained time-varying quadratic program ideally when time goes to infinity. The convergence performance is a significant improvement, as compared to the gradient-based dynamics (GD) that cannot make the error converge to zero even after infinitely long time. However, this ZD model with the suggested activation functions cannot reach the theoretical time-varying solution in finite time, which may limit its applications in real-time calculation. Therefore, a nonlinearly-activated neurodynamic model is proposed and studied in this paper for real-time solution of the equality-constrained quadratic optimization with nonstationary coefficients. Compared with existing neurodynamic models (specifically the GD model and the ZD model) for optimization, the proposed neurodynamic model possesses the much superior convergence performance (i.e., finite-time convergence). Furthermore, the upper bound of the finite convergence time is derived analytically according to Lyapunov theory. Both theoretical and simulative results verify the efficacy and superior of the nonlinearly-activated neurodynamic model, as compared to these of the GD and ZD models. © 2015 Elsevier B.V. All rights reserved.

To investigate the diversity of cultivable halophilic and halotolerant bacteria isolated from ordinary non-saline soil samples collected from Xiaoxi National Natural Reserve (28 degrees 42' 15"-28 degrees 53' 15" N, 110 degrees 6' 50"-110 degrees 21' 35" E), Hunan Province, China. Bacterial strains were isolated from the samples by using the conventional culture-dependent method and investigated by using phylogenetic analysis based on 16S rRNA gene sequence comparisons. We isolated 114 bacterial strains (8 moderately halophilic, 19 slightly halophilic, 87 halotolerant) from the samples on media (marine agar 2216, International Streptomyces Project medium 2 and 5, nutrient and humic acid agars) supplemented with 5% to 20% (w/v) NaCl. On the basis of morphological, physiological and biochemical characteristics, we selected 61 strains to perform a phylogenetic analysis based on 16S rRNA gene sequences. Results showed that 61 isolates represented 41 species, belonging to 18 genera (Actinomadura, Arthrobacter, Bacillus, Brachybacterium, Brevibacterium, Erwinia, Halobacillus, Jeotgalibacillus, Microbacterium, Microbulbifer, Nocardia, Pseudomonas, Rheinheimera, Rhodococcus, Sphingomonas, Staphylococcus, Streptomyces, Yaniella) of 16 families ( Alteromonadaceae, Bacillaceae, Brevibacteriaceae, Chromatiaceae, Dermabacteraceae, Enterobacteriaceae, Microbacteriaceae, Micrococcaceae, Nocardiaceae, Planococcaceae, Pseudomonadaceae, Sphingomonadaceae, Staphylococcaceae, Streptomycetaceae, Thermomonosporaceae, Yaniellaceae) in three phyla (Actinobacteria, Firmicutes, Proteobacteria). The most abundant and diverse isolates were within the phylum Firmicutes (38 strains; 62.3%) and the phylum Actinobacteria (18 strains; 29.5%). The phylogenetic distance matrix results suggested that there were obvious genetic divergences between most isolates and their closestly related type strains (16S rRNA gene sequence similarities ranged from 96.9% to 99.8%), and that, out of 61 isolates, at least 7 strains (JSM 070026, JSM 081004, JSM 081006, JSM 081008, JSM 083058, JSM 083085, JSM 084035) should represent 7 potential novel species within 6 characterized genera (Yaniella, Bacillus, Jeotgalibacillus, Sphingomonas, Rheinheimera, Microbulbifer). The results presented here showed that there is abundant diversity of halophilic and halotolerant bacteria, as well as a number of novel species in non-saline soil collected from Xiaoxi National Natural Reserve, Hunan Province, China.

Xiong L.,JiShou University | He Z.,JiShou University
Polymer - Plastics Technology and Engineering | Year: 2013

Methoxy polyethylene glycol and poly(D, L-lactide) (mPEG/PLA) copolymers with various composition were synthesized by using ring-opening polymerization method and characterized by Fourier transform infrared spectroscopy (FT-IR). mPEG/PLA microspheres were prepared by double emulsion method. 5-fluorouracil (5-FU), as an anticancer drug, was successfully loaded in these microspheres. The obtained microspheres were characterized for entrapment efficiency, drug loading, and in-vitro release studies and subjected to optical microscopy and scanning electron microscopy (SEM). The results indicated that the microspheres showed spherical shape, homogeneous particle size distribution and smooth surfaces. The percentage of loading and encapsulation efficiency of 5-FU decreased with increasing amount of mPEG in the microspheres and decreasing concentration of mPEG/PLA. 5-FU showed a typical bimodal in-vitro release behavior from mPEG/PLA microspheres and the release kinetics indicated Fickian diffusion. In-vitro cytotoxicity analysis on HT-29 cell lines demonstrated that 5-FU loaded mPEG/PLA microspheres possess the potential to delay the apoptosis for a long time. © 2013 Copyright Taylor and Francis Group, LLC.

Tan D.Y.,JiShou University
Sheng li ke xue jin zhan [Progress in physiology] | Year: 2012

Prolactin (PRL) is secreted by lactotrophs in the anterior pituitary and some extra-pituitary tissues such as breast, lacrimal gland, uterus, thymus and spleen, etc. Since PRL is closely related to growth hormone (GH) and placental lactogens (PL), it has been broadly accepted that PRL, GH and PL are resulted from the duplication of an ancestral gene. PRL regulates hundreds of biological functions by endocrine, paracrine and autocrine manners. Prolactin initiates its effects by binding to its receptor (PRLR). PRLR belongs to the class I cytokine receptor superfamily. Up to now, three membrane--PRLRs have been clarified. They are long form (LF), intermediate form (IF) and short form (SF) including SFla and SFlb. All PRLRs are derived from a primary transcript of common gene through alternative splicing mechanism. Although the extracellular domain (ECD) and the transmembrane domain (TD) of LF, IF and SF are equal, different isoforms of PRLR exert different function through different intracellular domain. It has been well documented that abnormity of PRLR is closely related to the pathogenesis, progression and prognosis of cancers including breast cancer. Several PRLR antagonists have been well designed and evidenced to have the potential to be important therapeutics.

Xiong L.,JiShou University | He Z.,JiShou University
Polymer - Plastics Technology and Engineering | Year: 2012

Blend microspheres of poly(vinyl alcohol) (PVA) with chitosan (Cs) were prepared as candidates for oral delivery system. Cs/PVA microspheres containing 2,4-dihydroxy-5-fluoropyrimidine (5-FU) were obtained using glutaraldehyde (GA) as a cross-linking agent. The effects of cross-linker concentration and cross-linking time on the release of 5-FU were investigated, and the cytotoxicities of free 5-FU and the PVA/Cs microspheres loaded with 5-FU were also studied. It was observed that 5-FU release from the microspheres decreased with the increase of cross-linking concentration and cross-linking time. Cytotoxicity tests of free and entrapped 5-fluorouracil were carried out with MCF-7 breast cancer cell line. Free 5-FU produced an immediate effect, whereas entrapped 5-fluorouracil showed a prolonged cytotoxic effect. © 2012 Copyright Taylor and Francis Group, LLC.

A Gram-stain-positive, endospore-forming, motile, catalase- and oxidase-positive, aerobic, rod-shaped bacterium, designated strain JSM 081008(T), was isolated from non-saline forest soil in China. Strain JSM 081008(T) was able to grow with 0-20% (w/v) NaCl, at pH 6.0-10.5 and at 10-45 degrees C; optimum growth was observed with 2-5% (w/v) NaCl, at pH 7.0-8.0 and at 30-35 degrees C. The peptidoglycan type was A1alpha linked directly through L-Lys. The major cellular fatty acids (>10% of the total) were anteiso-C15:0, iso-C15:0, anteiso-C17:0 and C16:0. The predominant respiratory quinone was menaquinone 7 and the genomic DNA G + C content of the strain was 42.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 081008(T) should be assigned to the genus Jeotgalibacillus and was related most closely to the type strains of Jeotgalibacillus alimentarius (sequence similarity 99.4%) and Jeotgalibacillus salarius (97.0%), followed by Jeotgalibacillus campisalis (95.4%) and Jeotgalibacillus marinus (95.2%). The combination of phylogenetic analysis, DNA-DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the view that strain JSM 081008(T) represents a novel species of the genus Jeotgalibacillus, for which the name Jeotgalibacillus soli sp. nov. is proposed. The type strain is JSM 081008(T) (=DSM 22174(T) = KCTC 13528(T)). An emended description of the genus Jeotgalibacillus is also presented.

Chen Y.G.,JiShou University
Antonie van Leeuwenhoek | Year: 2010

A novel Gram-stain-positive, slightly halophilic, facultatively alkaliphilic, non-motile, non-sporulating, catalase-positive, oxidase-negative, aerobic bacterium, designated strain JSM 070026(T), was isolated from non-saline forest soil in China. Growth occurred with 0-20% (w/v) NaCl (optimum, 2-4%) and at pH 6.0-10.5 (optimum, pH 8.0) and 5-40 degrees C (optimum, 30 degrees C). Good growth also occurred in the presence of 0-28% (w/v) KCl (optimum, 2-5%) or 0-25% (w/v) MgCl(2)*6H(2)O (optimum, 1-4%). The peptidoglycan type was A4alpha (L: -Lys-Gly-L: -Glu). Cell-wall sugars contained mannose and xylose. The major cellular fatty acids were anteiso-C15:0 and iso-C15:0. Strain JSM 070026(T) contained menaquinone 8 as the major respiratory quinone and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the major polar lipids. The DNA G + C content of strain JSM 070026(T) was 56.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JSM 070026(T) was a member of the suborder Micrococcineae and most closely related to Yaniella flava YIM 70178(T) (sequence similarity 99.4%) and Yaniella halotolerans YIM 70085(T) (97.9%). The three strains formed a distinct branch in the phylogenetic tree. The combination of phylogenetic analysis, DNA-DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the proposal that strain JSM 070026(T) represents a novel species of the genus Yaniella, for which the name Yaniella soli sp. nov. is proposed. The type strain is JSM 070026(T) (=DSM 22211(T) = KCTC 13527(T)).

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