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The cerebellum receives sensory inputs from mossy fiber-granule cell or climbing fiber pathways, and generates motor-related outputs. However, the temporal and special mechanism of the sensory information processing in cerebellar cortex is still unclear. Therefore, we here investigated the temporal-spacial mechanism between the facial stimulation-evoked field potential responses in granular layer (GL) and molecular layer (ML), by duo-electrophysiological recording technique and pharmacological methods in urethane-anesthetized mice. Our results showed that air-puff stimulation of ipsilateral whisker pad evoked successively field potential responses in GL and ML. The field potential response in GL exhibited a strong excitatory component (N1) followed by an inhibitory component (P1), while the field potential response in ML exhibited a tiny excitatory component (N1) followed by strong inhibitory component (P1). The latency of N1 was decreased with the increase of recording depth in ML, and it was the shortest in GL. Notably, the latencies of P1 in GL and ML were similar regardless the relative recording sites. Furthermore, blocking α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated parallel fiber excitatory inputs by application of AMPA receptor antagonist, NBQX prevented P1 in both ML and GL. Moreover, application of GABAA receptors antagonist, gabazine simultaneously abolished P1 in both ML and GL. These results indicate that the facial stimulation evoked a simultaneous GABAergic inhibition in both ML and GL via mossy fiber-GC-parallel fiber pathway, suggesting that the sensory stimulation simultaneously evoked excitation of molecular layer interneurons (MLIs) and GL Golgi cells in cerebellar cortex.

Propofol is a widely used intravenous sedative-hypnotic agent, which causes rapid and reliable loss of consciousness via activation of γ -aminobutyric acid A (GABAA) receptors. We previously found that propofol inhibited cerebellar Purkinje cells (PC) activity via both GABAA and glycine receptors in vivo in mice. We here examined the effect of propofol on the cerebellar parallel fiber (PF)-PC synaptic transmission in mouse cerebellar slices by whole-cell recording technique and pharmacological methods. We found that following blockade of GABAA and glycine receptors activity, propofol reversely decreased the amplitude of PF-PC excitatory postsynaptic currents (PF-PC EPSCs), and significantly increased paired-pulse ratio (PPR). The propofol-induced decrease in amplitude of PF-PC EPSCs was concentration-dependent. The half-inhibitory concentration (IC50) of propofol for inhibiting PF-PC EPSCs was 4.7 μM. Notably, the propofol-induced changes in amplitude and PPR of PF-PC EPSCs were abolished by GABAB receptor antagonist, saclofen (10 μM), but not blocked by N-methyl-D-aspartate receptor (NMDA) receptor antagonist, D-APV (50 μM). Application of the GABAB receptor agonist baclofen induced a decrease in amplitude and an increase in PPR of PF-PC EPSCs, as well masked the propofol-induced changes in PF-PC EPSCs. Moreover, the propofol-induced changes in amplitude and PPR of PF-PC EPSCs were abolished by a specific protein kinase A (PKA) inhibitor, KT5720. These results indicate that application of propofol facilitates presynaptic GABAB receptors, resulting in a depression of PF-PC synaptic transmission via PKA signaling pathway in mouse cerebellar cortex. The results suggest that the interaction with GABAB receptors may contribute to the general anesthetic action of propofol.

Aflatoxins (AFs) are a series of highly toxic and carcinogenic secondary metabolites. In order to eliminate AFs contamination, biological control is one of the more promising techniques. In this study, we describe the optimization of media nutrients for the selected biocontrol bacterium, Lysinibacillus xylanilyticus strain BPM1. The strain was isolated from the peanut hulls in Shandong Province, China and exhibited antagonistic activity against aflatoxins. Maltose and sucrose were identified as best carbon source, while soya peptone and yeast extract as nitrogen source led to the highest OD600 observations. Medium composition was optimized using Plackett-Burman design, which was applied to find the key ingredients. The results revealed that the most significant two factors which were more effective in the fermentation of L. xylanilyticus BPM1 were soya peptone and yeast extract.

Chitinase is one of the most important mycolytic enzymes with industrial significance, and produced by a number of organisms. A chitinase producing isolateSerratia marcescensJPP1 was obtained from peanut hulls in Jiangsu Province, China, and exhibited antagonistic activity against aflatoxins. In this study, we describe the optimization of medium composition with increased production of chitinase for the selected bacteria using statistical methods: Plackett-Burman design was applied to find the key ingredients, and central composite design of response surface methodology was used to optimize the levels of key ingredients for the best yield of chitinase. Maximum chitinase production was predicted to be 23.09 U/mL for a 2.1-fold increase in medium containing 12.70 g/L colloidal chitin, 7.34 g/L glucose, 5.00 g/L peptone, 1.32 g/L (NH4)2SO4, 0.7 g/L K2HPO4, and 0.5 g/L MgSO4·7H2O. Polymerase chain reaction (PCR) amplification of the JPP1 chitinase gene was performed and obtained a 1,789 bp nucleotide sequence; its open reading frame encoded a protein of 499 amino acids named as ChiBjp.

Serratia marcescens strain JPP1 was isolated from the peanut hulls in Jiangsu Province, China. The strain exhibited antagonistic activity against aflatoxins production and chitinolytic activity by producing chitinases. For chitinase production glucose was identified as best carbon source, peptone as organic nitrogen source while ammonium sulphate as the best inorganic nitrogen source led to the highest chitinase activity. Chitin served as an essential inducer and chitinase production reached the peak level after 1.2% of chitin concentration. The crude chitinase was highly thermostable and had activity in broad pH (2-11) and temperature (30-90°C) range. Ca and Mn ions enhanced the chitinase production, while Na and K were of inhibitory action not more than 5%, and Cu, Zn and Fe ions resulted in drastic enzyme inhibition ranged between 63.7 to 70.5%. Addition of EDTA, mercaptoethanol and Tween 80 had positive effect on chitinase production while SDS decreased the chitinase production by S. marcescens JPP1.

Polysaccharides extracted from fruiting body and mycelia of higher fungi have been found to show various biological activities. Traditionally, these polysaccharides are manufactured by the hot water extraction method. Low polysaccharide yield is the disadvantage of this method. This paper reports the optimal conditions to manufacture polysaccharide with high-yield from Hypsizigus marmoreus mycelia using enzymatic hydrolytic extraction method. Neutral protease was selected as the most cost efficient among six enzymes. The uniform design was further conducted to optimize the enzymatic hydrolytic extraction conditions, and a regression model was constructed to predict polysaccharide yield. The optimized procedures was that 2% (w/w) of neutral protease was added into hydrolytic solution and incubated for 4 h at 43°C, then extracted one time at 100°C for 1 h. Under optimized procedures, the measured polysaccharide yield was 15.73±0.15 (mg/g), which was very close to the predicted value of 16.65 (mg/g). The results validated the accuracy of the regression model and the optimized procedure. When following the optimized procedures, polysaccharide yield was raised 75.0% over that before optimization, and increased by 122.5% and 104.8% over hot-water extraction and microwave assisted extraction methods respectively. This was the first study to apply uniform design for optimizing high yield manufacture of mycelia polysaccharides by enzymatic hydrolytic extraction. We concluded that enzymatic hydrolytic extraction was a simple, high yield method to manufacture polysaccharides from mushroom mycelia and might be used widely in polysaccharide-derived functional foods production.

Bacillus subtilis is potential to play an important role on biological control of aflatoxin-producing fungi. The liquid fermentation medium of Bacillus subtilis LN for production of bioactive metabolites inhibitory to mycelial growth and aflatoxin biosynthesis was optimized by single factor experiments. The results showed that optimum carbon source was glucose, the optimum nitrogen source was soy peptone, and the optimum inorganic salt was MgSO4.These screened optimal carbon, nitrogen and inorganic salt sources could be used for high yield fermentation of bioactive metabolites for developing biopesticide against aflatoxin contamination in foods.

Ypsizigus marmoreus is a newly cultivated medicinal and edible mushroom with higher antitumor activity. In this paper, a uniform design was used to optimize the medium formula with four factors each at six levels, and a regression model was constructed to predict the antitumor exopolysaccharide production. The optimal concentrations for the enhanced exopolysaccharide production were determined as 30% (w/v) glucose, 8.4% (w/v) soybean peptone, 3% (w/v) KH2PO4and 30% (w/v) sweat potato flour. Subsequent experiment confirmed the validity of the model. Under the optimal condition, exopolysaccharide yield reached 3.39g/L in shake-flask culture, which was 3.53 fold higher than that obtained in the basic medium. The results highlight the future application of optimized medium for high yield production of antitumor exopolysaccharide by fermentation of Hypsizigus marmoreus.

A label free impedimetric immunosensor for the determination of aflatoxin B1 (AFB1) was fabricated by immobilizing anti-AFB1 onto Poly o-phenylenediamine (PoPD) electropolymerized film modified gold electrode by glutaraldehyde (GA) cross-linking. An electrochemical interfacial modeling of biomolecular recognition was recommended and reasonably interpreted. EIS technology was employed for the quantitative determination. The linear detection concentration ranges of AFB1 were 0.03~0.1 μg/mL and 0.1~0.7 μg/mL. The detection limit was 2.8×10-8μg/mL. The immunosensor could be reused more than 10 times when renewed by HCl-Glycine buffer solution (pH 2.6).

Multilayers of Y-type bilayers of pure and mixed erbium palmitate(EP), nonadecanate(EN) and behenate(EB) on CaF2 substrates were prepared by conventional Langmuir-Blodgett (LB) method. It is demonstrated that two systems composed of alternating bilayer of different fatty acid salts are unidimensional superlattices. These LB films were characterized by means of x-ray photoelectronic Spectrometry (XPS), FTIR and x-ray diffraction (XRD) measurements.

The increasing commercial significance of natural polysaccharides for use in medicinal products is stimulating the development of efficient and easy scale-up techniques for polysaccharide purification. In this research, the crude polysaccharides from submerged cultivation broth of Hypsizigus marmoreus were purified using radial flow chromatography (RFC), and the antiproliferative activity of the purified fractions was evaluated in vitro. DEAE Sepharose CL-6B was selected to be packed in the RFC column based on its good resolution, physical stability, and low cost. Compared with axial flow chromatography (AFC), an efficient chromatographic process with significantly less time and buffer consumption but yielding higher polysaccharide recovery and resolution was established in RFC, which could clearly purify the crude polysaccharides into different fractions. An acceptable linear scale-up effect of RFC from 100 to 500 mL was successfully achieved without loss of resolution and enhancement of time consumption. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in cell cultures indicated that the purified polysaccharide fractions possess moderate antiproliferative activities in three different human cancer cell lines, but have significantly lower cytotoxicity in normal human cell lines in vitro. Among the polysaccharide fractions, the main purified acidic fraction W-I could be considered as a novel potential antitumor agent candidate for several tumors, especially for human alveolar epithelial tumors. This research confirmed for the first time that RFC would be a new fast and efficient tool for purification of polysaccharides into different fractions, both at laboratory and commercial scales. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:872–878, 2014

Acetylene hydrogenation on both the perfect and oxygen defective anatase TiO(2)(101) surfaces supported Pd(4) cluster has been studied using density functional theory calculations with a Hubbard U correction (DFT + U). The adsorbed Pd(4) cluster on the perfect surface prefers to form a tetrahedral structure, while it likely moves to the oxygen defective site to form a distorted tetrahedral structure by removing a bridging oxygen atom. For the defective surface, it exhibits a stronger ability to capture Pd(4) cluster as charge transfer is significantly performed due to the oxygen deficiency. Moreover, it is found that the oxygen defective surface shows higher activity for acetylene hydrogenation, and the possible reason may lie in the weaker adsorption strength between the Pd cluster and the adsorbed molecules on the defective surface as compared to the case on the perfect surface.