Determination of the transfer of lead and chromium from feed to raw milk in Holstein cows.

In this study, we aimed to determinate the transfer of lead (Pb) and chromium (Cr) from feed to raw milk in Holstein cows. Solutions of lead acetate and chromium (III) nicotinate were added together at different levels to individual portions of feed on a daily basis. Lead administration for the low-, middle- and high-dosage groups was controlled as 0.9, 1.8 and 3.6 g/day for 30, 30 and 25 days, while chromium was feed at 0.47, 1.5 and 4.7 g/d for 40, 40, and 40 days, respectively. A sensitive graphite furnace atomic absorption spectrometry (GFAAS) method was developed and optimised with a respective limit of detection of lead and chromium found to be 1 and 5 µg kg-1 raw milk. The optical wavelengths for detection of lead and chromium were 283.31 nm and 357.87 nm respectively. The results showed that the highest concentrations of lead in raw milk for the low-, middle- and high-dosage groups were 0.083 ± 0.021, 0.215 ± 0.064 and 0.232 ± 0.035 mg kg-1, which displayed a positive correlation with dosage levels. In addition, a high dosage level accompanied a greater rate of loss of lead contents after dosing withdrawal. However, chromium concentrations maintained a relatively stable range around 0.1 mg kg-1 raw milk for all dosing groups and showed little transfer from feed to raw milk through the whole experiment.

Administration of Lactobacillus paracasei ameliorates type 2 diabetes in mice.

Probiotics have been proposed as an option for the prevention of type 2 diabetes mellitus (T2DM). The objective of this study was to evaluate the hypoglycemic effects of Lactobacillus paracasei on diabetic mice and explore the possible underlying molecular mechanism. The α-glucosidase inhibitory activities of eight L. paracasei strains were assessed in vitro. L. paracasei TD062 with high α-glucosidase inhibitory activity (31.9%) showed an excellent antidiabetic ability and it could survive in simulated gastrointestinal juices. To investigate the beneficial effects of L. paracasei TD062, diabetic mice were treated with the strain at 109, 108 and 107 CFU ml-1. The results indicated that the administration of L. paracasei TD062 could regulate the levels of fasting blood glucose (FBG), postprandial blood glucose (PBG), glucose tolerance, hepatic glycogen and lipid metabolism. In addition, the antioxidant capacity was also improved by oral administration of L. paracasei TD062. And the hypoglycemic effects exhibited dose dependence to some extent. Furthermore, it was revealed that L. paracasei TD062 had a positive effect on the expression levels of genes related to glucose metabolism and the PI3K/Akt pathway. These results demonstrated that L. paracasei TD062 played an important role in preventing the development of T2DM and might be applied as a new type of hypoglycemic agent in functional foods.

Transcriptomic response to GABA-producing Lactobacillus plantarum CGMCC 1.2437T induced by L-MSG.

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter found in the central nervous system of mammals. A range of bacterial species can synthesize GABA, including Lactobacillus plantarum of which L-monosodium glutamate (L-MSG) is an inducer of its production. In order to synthesize GABA in high concentrations, L-MSG was utilized as the single inducing factor, a chemically defined medium (CDM) was used as the fermentation substrate, with L. plantarum CGMCC 1.2437T cultured in medium supplemented with or without L-MSG. High-throughput transcriptome sequencing was used to explore the differential genes expression of bacterial cells at 36 h of fermentation, where the GABA concentration of CDM with L-MSG reached the peak value and was 7.7 times higher than that of medium without L-MSG at the same timepoint. A total of 87 genes showed significant differential expression induced by L-MSG: of these, 69 were up-regulated genes and 18 were down-regulated. The up-regulated genes were assigned to biological processes and molecular function, while the down-regulated genes covered biological process, cellular process and molecular function. Interrogation of results using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, indicated carbohydrate metabolism, fatty acid synthesis and amino acid metabolism were closely associated with GABA synthesis induced by L-MSG. This study provides insights into L. plantarum-mediated GABA fermentation at the molecular level and will provide a new approach for further studies related to GABA production by the other Lactic acid bacteria.

Luminescent properties of sol-gel processed red-emitting phosphor Ca0.6 Sr0.4-1.5x-0.5y Mo0.4 W0.6 O4:Eux Liy.

A series of red-emitting phosphors Ca0.6Sr(0.4-1.5x-0.5y)Mo0.4W0.6O4:Eux Liy (x = 0.02-0.12, y = 0-0.12) has been synthesized by a sol-gel method. The effects of calcining temperature, concentrations of Li(+) and Eu(3+) , and compensation ions on the luminescent properties were investigated. X-ray diffraction and scanning electron microscopic results showed that as-prepared phosphors were of single phase with several microns. The Li(+) compensated compositions showed remarkably intense red emission at 619 nm. The emission intensity of the series reached maximum for compositions at x = 0.08 and y = 0.08 when the calcining temperature was 900 °C.

Electrochemical characterization of poly-beryllon II modified carbon paste electrode and its application to selective determination of pyrocatechol and hydroquinone.

A poly-beryllon II film modified carbon paste electrode (PBL-II/CPE) has been constructed by electropolymerization method. Electrochemical characterization of the PBL-II/CPE was investigated by electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of pyrocatechol (PC) and hydroquinone (HQ) were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at the PBL-II/CPE in pH 7.0 phosphate buffer solution (PBS). The anodic peak currents were dramatically enhanced about threefold for PC at PBL-II/CPE. In addition, the modified electrode exhibits good selectivity toward selective determination of PC and HQ. By using DPV method, low detection limits of 0.8µM for PC and 1.0µM for HQ were obtained, respectively. Many outstanding advantages, such as wide linear ranges, low detection limits, excellent sensitivity, selectivity and stability confirmed that the PBL-II/CPE has promising analytical performance. Meanwhile, the electrode was successfully used for the determination of PC and HQ in local tap water sample and the results are satisfactory.

Diaqua-bis(pyrazine-2-carboxyl-ato-κN,O)manganese(II) dihydrate.

In the title compound, [Mn(C(5)H(3)N(2)O(2))(2)(H(2)O)(2)]·2H(2)O, the Mn(II) atom, lying on an inversion centre, has a distorted octa-hedral environment and the molecules are linked by O-H⋯O and N-H⋯O hydrogen bonds to form a three-dimensional supra-molecular structure.

(E)-4-Methyl-2-[(R)-1-phenyl-ethyl-imino-meth-yl]phenol.

In the title Schiff base, C(16)H(17)NO, the dihedral angle between the two aromatic rings is 63.59 (2)°. A strong intra-molecular O-H⋯N hydrogen bond is observed between the hydroxyl group and the imine N atom.

4,4'-Dimethyl-2,2'-[(3-aza-pentane-1,5-di-yl)bis-(nitrilo-methyl-idyne)]diphenol.

In the crystal structure of the title Schiff base, C(20)H(25)N(3)O(2), the salicylaldimine groups at each end of the mol-ecule are essentially planar and make a dihedral angle of 84.94 (3)° with each other. There are strong intra-molecular O-H⋯N hydrogen bonds and a weak inter-molecular N-H⋯O hydrogen bond.

Bis{2-[(E)-benzyl-imino-meth-yl]-4-methyl-phen-olato-κN,O}cobalt(II).

In the title complex, [Co(C(15)H(14)NO)(2)], the Co(II) atom, situated on an inversion centre, is coordinated by two O and two N atoms from two symmetry-related bidentate Schiff base ligands in a slightly distorted square-planar geometry. The two phenolate rings form a dihedral angle of 10.53 (2)°.

A new highly selective fluorescent silver probe.

We have synthesized 3,3,7,7-tetra[N-ethyl-N-benzyl(acetamide)-2-oxymethyl]-5- oxanonane (EBAOO) and its terbium complex. The crystal structures of the complex were determined: [Tb(EBAOO)](2)[Tb(NO(3))(5)](3).H(2)O, Orthorhombic, a=40.722 (6) A, b=18.418 (3) A, c=20.496 (3) A. In the structure, the rare earth ion satisfies nine coordination. The geometry of the nine-coordinate polyhedron is discussed in terms of the dihedral angle and the mean plane. The luminescence of the complex is noticeably enhanced upon complexation with Ag(+), which is due to the suppression of photoinduced electron transfer (PET) process. Therefore, the terbium complex can be used as a selective fluorescent silver probe.

Synthesis, infrared and fluorescence spectra of lanthanide complexes with a new amide-based 1,3,4-oxadiazole derivative.

A new amide-based 1,3,4-oxadiazole derivative ligand 2,5-bis[2-(N,N-diethyl-1'-oxopropylamide)phenyl]-1,3,4-oxadiazole (L) and its complexes, Ln(NO3)3L (Ln=La, Eu, Gd, Tb, Er), were synthesized. The complexes were characterized by elemental analysis, infrared spectra and conductivity. The lanthanide ions were coordinated by O atoms from CO. The fluorescence properties of Eu(NO3)3L and Tb(NO3)3L in the solid state and in different solvents were investigated. Under the excitation of UV light, these complexes exhibit characteristic fluorescence of europium and terbium ions. The solvent factors influencing the fluorescent intensity were discussed.

Enhanced fluorescence of 3-(naphthalene-2-ylimino)-1-phenylbutan-1-one-Tb with 1,10-phenanthroline ternary system and its analytical application.

A new Schiff base ligand: 3-(naphthalene-2-ylimino)-1-phenylbutan-1-one (NPB) was synthesized. Its fluorescence intensity with terbium(III) was greatly enhanced by the addition of 1,10-phenanthroline (Phen) in the chloroform solution. The mechanism of fluorescence enhancement was studied. The results indicate the formation of a ternary NPB-Phen-Tb complex. In the ternary system, Phen can transfer the energy absorbed by Phen and NPB to Tb(3+).

The new fluorescence enhancement system Tb-N-(2-pyridinyl) ketoacetamide-Et(3)N-Zn and its application.

A sensitive fluorescence enhancement system was developed for the determination of terbium. The fluorescence intensity of the Tb-N-(2-pyridinyl) ketoacetamide (PKAA) system was greatly enhanced by the addition of triethylamine (Et(3)N) and zinc nitrate in the methanol solution. The excitation and emission wavelengths were 329 and 546 nm, respectively. Under optimal conditions, the fluorescence intensities varied linearly with the concentration of Tb(3+) in the range of 7.5 x 10(-8)-8.2 x 10(-6)M with a detection limit of 6.4 x 10(-8)M. The interferences of some rare earth ions were described. This method was applied to the determination of trace amounts of terbium (III) in a synthetic rare earth oxide and a high purity Y(2)O(3) matrix. The mechanism of fluorescence enhancement was also studied.

Study on the new fluorescence enhancement system of Tb -N-(2 - pyridinyl) ketoacetamide-Et3N-Zn and its application.

A sensitive fluorescence enhancement system was developed for the determination of zinc (II). The fluorescence intensity of the Tb- N- (2 - Pyridinyl) ketoacetamide (PKA) system was greatly enhanced by the addition of triethylamine (Et(3)N) and zinc nitrate in the methanol solution. The excitation and emission wavelengths were 329 nm and 546 nm, respectively. Under optimal conditions, the fluorescence intensities varied linearly with the concentration of Zn(2+) in the range of 8.0 x 10(-7)-5.0 x 10(-6) M with a detection limit of 9.9 x 10(-8) M. The interferences of some substances were described. This method was applied to the determination of amounts of Zn(2+) in soybean, rice, and wheat, respectively. The results showed that the proposed procedure is a high selective, simple, and rapid method to the determination of Zn(2+) ion. The mechanism of fluorescence enhancement was also studied.