Characterization and antivibrio activity of chitosan-citral Schiff base calcium complex for a calcium citrate sustained release antibacterial agent.

Vibrio parahemolyticus is the "Number one killer" of seafood products. Anti-vibrio agents having low cost and high-safety are urgently needed to supplement the application needs. This work attempted to prepare CS-CT-CCa complex with citral (CT), chitosan (CS) and calcium citrate (CCa) as raw material by microwave-assisted high-pressure homogenization. Additionally the coordination structure and morphology of Bridge-CS-CT-Schiff base/OH-CCa were verified. The prepared CS-CT-CCa had a well-dispersed property (the size: 3.55~9.33 µm and the zeta potential: +38.7~+67.5 mV) and an excellent sustained released ability (sustained release up to 180 min). MIC, Glucose assay, MDA assay, biofilm formation inhibition assay, SEM, swimming and swarming motility assay demonstrated that CS-CT-CCa had strong (MIC of 128 µg/mL) and sustained (more than 12 h) inhibitory effects against V. parahaemolyticus. Meanwhile, CS-CT-CCa could increase the membrane permeability of V. parahaemolyticus and inhibit their biofilm-forming ability in a dose-dependent manner. It could be inferred that the antibacterial activities against V. parahaemolyticus caused inhibition of biofilm formation, swimming and swarming motilities. This study provided necessary data for the further design and development of chitosan antibacterial agents, food and feed additives.

Promoting Aromatic Hydrocarbon Formation via Catalytic Pyrolysis of Polycarbonate Wastes over Fe- and Ce-Loaded Aluminum Oxide Catalysts.

Converting polycarbonate (PC) plastic waste into value-added chemicals and/or fuel additives by catalytic pyrolysis is a promising approach to dispose of solid wastes. In this study, a series of Fe-Ce@Al2O3 metal oxides were prepared by coprecipitation, impregnation, and a direct mixing method. The synthesized catalysts were then employed to investigate the catalytic conversion of PC wastes to produce aromatic hydrocarbons. Experimental results indicated that Fe-Ce@Al2O3 prepared by coprecipitation possessed superior catalytic activity because of its high content of weak acid sites, large pore volume, high surface area, and well dispersion of Fe and Ce active species, leading to an ∼3-fold increase in targeted monocyclic aromatic hydrocarbons compared to that achieved noncatalytically. Moreover, an increase in the catalyst to feedstock (C/F) mass ratio was beneficial to the production of aromatic hydrocarbons at the expense of phenolic products, and elevating the C/F ratio from 1:1 to 3:1 considerably increased the benzene formation as the enhancement factor was increased from 2.3 to 8.8.

Methanolysis Fractionation and Catalytic Conversion of Poplar Wood toward Methyl Levulinate, Phenolics, and Glucose.

In the present study, methanolysis of poplar biomass was conducted for the selective transformation of hemicellulose and lignin, which leads to methyl glycosides (mainly C5 glycosides) and lignin fragments in the liquefied products that can be separated according to their difference in hydrophilicity. The distribution of methyl glycosides and delignification was dependent on the presence of acid catalysts and reaction temperatures. The obtained lignin fraction was separated into solid lignin fragments and liquid lignin oil according to their molecular weight distribution. Subsequently, directional conversion of methyl C5 glycosides into methyl levulinate was performed with dimethoxymethane/methanol as the cosolvent. A yield of 12-30% of methyl levulinate yield (based on the methyl glycoside) was achieved under these conditions. The remaining cellulose-rich substrate showed enhanced susceptibility to enzymatic hydrolysis, resulting in a yield of glucose of above 70%. Overall, the described strategy shows practical implications for the effective valorization of biomass.

Expression and characterization of recombinant Rhizopus oryzae lipase for enzymatic biodiesel production.

The Rhizopus oryzae lipase containing prosequence was expressed in Pichia pastoris. Recombinant lipase subunit showed a molecular mass of 32 kDa. The maximum activity of recombinant lipase obtained from Mut(s) recombinant was 90 IU/ml. The enzyme was stable in broad ranges of temperatures and pH, with the optimal temperature at 35 °C and pH 7.0. The crude recombinant R. oryzae lipase can be directly used for the transesterification of plant oils at high-water content of 60-100% (w/w) based on oil weight. The addition of 80% water to the transesterification systems resulted in the yield of methyl ester of 95%, 94% and 92% after 72 h using soybean oil, Jatropha curcas seed raw oil and Pistacia chinensis seed raw oil as raw material, respectively. These results indicate that the recombinant lipase is an effective biocatalyst for enzymatic biodiesel production.

Production of hydrocarbon fuels from pyrolysis of soybean oils using a basic catalyst.

Triglycerides obtained from animals and plants have attracted great attention from researchers for developing an environmental friendly and high-quality fuel, free of nitrogen and sulfur. In the present work, the production of biofuel by catalytic cracking of soybean oil over a basic catalyst in a continuous pyrolysis reactor at atmospheric pressure has been studied. Experiments were designed to study the effect of different types of catalysts on the yield and acid value of the diesel and gasoline fractions from the pyrolytic oil. It was found that basic catalyst gave a product with relatively low acid number. These pyrolytic oils were also further reacted with alcohol in order to decrease their acid value. After esterification, the physico-chemical properties of these biofuels were characterized, and compared with Chinese specifications for conventional diesel fuels. The results showed that esterification of pyrolytic oil from triglycerides represents an alternative technique for producing biofuels from soybean oils with characteristics similar to those of petroleum fuels.

Biofuel production from catalytic cracking of woody oils.

The catalytic cracking reactions of several kinds of woody oils have been studied. The products were analyzed by GC-MS and FTIR and show the formation of olefins, paraffins and carboxylic acids. Several kinds of catalysts were compared. It was found that the fraction distribution of product was modified by using base catalysts such as CaO. The products from woody oils showed good cold flow properties compared with diesel used in China. The results presented in this work have shown that the catalytic cracking of woody oils generates fuels that have physical and chemical properties comparable to those specified for petroleum based fuels.

[Mechanism of Yiqi Huayu Bushen recipe in treating cervical syndrome in rats with qi deficiency, blood stasis and kidney deficiency].

OBJECTIVE: To explore the mechanism of Yiqi Huayu Bushen Recipe (YHBR), a compound traditional Chinese herbal medicine, in treating cervical syndrome (CS) with qi deficiency, blood stasis and kidney deficiency in rats. METHODS: A total of 30 three-month-old female Sprague-Dawley rats were randomly divided into normal control group, untreated group and YHBR group; there were ten rats in each group. The rat model of cervical syndrome with qi deficiency, blood stasis and kidney deficiency was established by combining disease and syndrome models. After one-month YHBR treatment in YHBR group, all rats were sacrificed. Serum, plasma and cervical intervertebral discs were detected and observed by radio-immunology, histopathology, immunohistochemistry, etc. RESULTS: Compared with those in the normal control group, rats in the untreated group showed obvious signs of deficiency in vital energy, such as tiredness, ptosis, few movement, bluish-purple tongue and tail and weight loss; the weight of uterus and appendages, and the ratio of cyclic adenosine monophosphate/cyclic guanosine monophosphate were decreased; hemorheological parameters and the expression of alpha-granular membrane protein (CD62p) were increased; the content of serum estradiol was decreased. YHBR could improve the above indexes except for the weight of uterus and appendages. HE staining showed annulus fibrosus with cracks, diminish of pulposus nucleus, and decrease in the height of intervertebral disc and the thickness of end-plate in the untreated group; and YHBR could improve the changes of cervical intervertebral discs, but no obvious changes in end-plate. Type II collagen protein (Col2a1)was distributed in every part of the annulus fibrosus in normal control group, but was decreased in untreated group; YHBR could increase Col2a1 expression in annulus fibrosus as compared with the untreated group. The expressions of Col2a1 and tissue inhibitor of metalloproteinase-1 (TIMP-1) mRNAs were decreased in untreated group as compared with the normal control group (P<0.01); the expressions of Col2a1 and TIMP-1 mRNAs were higher and matrix metalloproteinase-13 mRNA was lower in the YHBR group than those in the untreated group (P<0.05, P<0.01). CONCLUSION: YHBR may improve the condition of cervical syndrome with qi deficiency, blood stasis and kidney deficiency by regulating immune system, coagulation system and endocrine system, and delay the degeneration of cervical intervertebral disc by regulating extracellular matrix and metalloproteases in intervertebral disc.

[Mechanism of Yiqi Huayu Bushen Recipe in treating cervical syndrome with kidney deficiency in rats].

OBJECTIVE: To research the action mechanism of Yiqi Huayu Bushen Recipe (YHBR), a compound of traditional Chinese herbal medicine, in treating cervical syndrome (CS) with kidney deficiency in rats. METHODS: A total of 30 three-month-old female Sprague-Dawley rats were randomly divided into normal control group, CS with kidney deficiency model group (untreated group) and YHBR group, with 10 rats in each group. Rats in the normal control group received no treatment, while rats of the other two groups underwent resection of both cervical muscles and ovaries to establish the model of CS with kidney deficiency. Three months after surgery, rats in the YHBR group were intragastrically administered YHBR for one month. Another one month later, all rats were sacrificed. The content of serum estradiol (E2) was detected by radio-immunoassay; contents of plasma cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were tested, and the ratio of cAMP/cGMP was also calculated. Hemorheology was detected by Weissenberg's method; expression of alpha-granular membrane protein (CD62p) was detected by flow cytometry; HE staining was used to detect the histopathology of cervical intervertebral disc degeneration; type II collagen protein was detected by immunohistochemistry and aggrecan-1 (Agc1), type II procollagen gene, Col2a1, tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metalloproteinase-13 (MMP-13) mRNAs were detected by fluorescent quantization polymerase chain reaction. RESULTS: Compared with the untreated group, rats in the YHBR group showed an obvious increase in serum E2 content (P<0.05), and an increase in plasma cAMP and cGMP content without significant difference; hemorheological parameters and percentage of CD62p expression were significantly decreased in the YHBR group (P<0.05, P<0.01). YHBR could improve the degeneration of cervical intervertebral discs, decrease the Miyamoto scores (P<0.05), and increase the type II collagen. The expressions of Agc1, Col2a1 and TIMP-1 mRNAs were significantly increased and MMP-13 mRNA significantly decreased in YHBR group (P<0.05, P<0.01). CONCLUSION: YHBR may improve CS with kidney deficiency and delay the degeneration of cervical intervertebral disc by regulating the immune-metabolism system, coagulation system and endocrine system.

[Establishment of a rat model of cervical syndrome with qi deficiency, blood stasis and kidney deficiency].

OBJECTIVE: To establish a rat model of cervical syndrome with qi deficiency, blood stasis and kidney deficiency. METHODS: A total of 30 three-month-old female Sprague-Dawley rats were randomly divided into normal group, cervical syndrome group and cervical syndrome with qi deficiency, blood stasis and kidney deficiency group (combined group), with 10 rats in each group. Rats in the normal group received no treatment, rats in cervical syndrome group underwent resection of cervical muscles and ligaments as unbalanced dynamic and static animal model, and rats in combined group underwent resection of both cervical muscles and ovaries, swimming and irregular diet, and injection of adrenal cortex hormone and adrenaline two and a half months after resection as combined model. The qi deficiency, blood stasis and kidney deficiency were determined by observing behaviors and physical signs of the rats, detecting the contents of plasma cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), the hemorrheology, the expression of alpha-granular membrane protein (CD62p) and the serum estradiol (E(2)) content. The aggrecan-1, type II procollagen gene (Col2a1), matrix metalloproteinases-13 (MMP-13) and tissue inhibitor of metalloproteinases-1 (TIMP-1) mRNAs in cervical intervertebral discs were detected by histopathology, immunohistochemistry and real-time polymerase chain reaction. The cataplasia of the intervertebral discs was determined by detecting the histopathology, the expressions of type II collagen and type X collegen proteins, and the expressions of aggrecan-1 (Agc1), type II procollagen gene (Col2a1), matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1) mRNAs. RESULTS: Compared with those in the normal group and cervical syndrome group, the rats in the combined group were noted with obvious signs of deficiency of vital energy, such as depression, tiredness, ptosis, obvious weight loss and blue tail. And the ratio of cAMP/cGMP was decreased; the reducing viscosity was significantly up-regulated; the expression of CD62p was increased; the content of serum E(2) was decreased; the intervertebral disc structure was destructed; the cervical intervertebral disc was more seriously deteriorated. There exhibited a decrease in type II collagen protein expression, an increase in type X collagen protein expression, as well as decreases of Agc1, Col2a1 and TIMP-1 mRNA expressions in intervertebral disc, and the expression of MMP-13 mRNA was noted an increase. CONCLUSION: The rat model of cervical syndrome with qi-deficiency, blood stasis and kidney deficiency is established. Qi deficiency, blood stasis and kidney deficiency can aggravate cervical intervertebral disc degeneration.

[Establishment of a rat model of cervical syndrome with kidney deficiency].

OBJECTIVE: To establish a rat model of cervical syndrome (CS) with kidney deficiency. METHODS: A group of 30 three-month-old female Sprague-Dawley rats were randomly divided into normal control group, CS group and CS with kidney deficiency group (combined group), with 10 rats in each group. Rats in the normal control group received no treatment, rats in the CS group underwent only resection of cervical muscles and ligaments as unbalanced dynamic and static animal model, and rats in combined group underwent resection of both cervical muscles and ovaries as kidney deficiency model. Serum and cervical intervertebral discs were collected. Kidney deficiency was determined by observing the morphologic changes of uterus and appendages, detecting the weight of uterus and appendages and the content of serum estradiol (E(2)). The degeneration of intervertebral discs was determined by detecting the histopathology, the expressions of type II collagen and type X collagen proteins, and the expressions of aggrecan-1 (Agc1), type II procollagen gene (Col2a1), matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinases-1 (TIMP-1) mRNAs. RESULTS: Compared with those in the normal control group and CS group, the rats in the combined group were noted with the uterus atrophied, the caliber of oviduct thinned, the weight of uterus and appendages diminished obviously, the content of serum E(2) decreased, cervical intervertebral disc degenerated more seriously, type II collagen protein expression decreased, type X collagen protein expression increased, Agc1 and Col2a1 mRNA expressions in intervertebral disc decreased, and the MMP-13 mRNA expression increased. CONCLUSION: The rat model of CS with kidney deficiency is established. Kidney deficiency can aggravate cervical intervertebral disc degeneration.