Resonance Rayleigh scattering study of the inclusion complexation of chloramphenicol with beta-cyclodextrin.

The interaction of chloramphenicol and beta-cyclodextrin (beta-CD) in aqueous solution was studied using resonance Rayleigh scattering (RRS) technology. The molar ratio of the inclusion complex was 1:1 established by spectrophotometry. The RRS technology was first applied to the determination of the inclusion constant of chloramphenicol to beta-CD.

A study on the interaction of proteins with some heteropoly compounds and their analytical application by resonance Rayleigh scattering method.

In the dilute sulfuric acid medium, the reactions of proteins with some heteropoly compounds (HPC) including some heteropoly acids (HPA) and their reducing products would result in the enhancement of resonance Rayleigh scattering (RRS) intensity and the appearance of the corresponding RRS spectra. Their maximum scattering peaks were all at 470nm, and there were four smaller peaks at 400, 510, 800 and 940nm, respectively. In a certain range, the concentrations of proteins were directly proportional to the enhanced intensities of RRS.

Flow-injection chemiluminescence determination of aminomethylbenzoic acid and aminophylline based on N-bromosuccinimide-luminol reaction.

A novel and sensitive chemiluminescence (CL) method for the determination of aminomethylbenzoic acid and aminophylline coupled with flow-injection analysis (FIA) technique is developed in this paper. It is based on the inhibition effect of the studied drugs on the chemiluminescence emission of N-bromosuccinimide-luminol (NBS-luminol) system. Under the optimum conditions, the decreased CL intensity is linear with the concentration of aminomethylbenzoic acid in the range of 2x10(-8) to 1.

Catalytic resonance scattering spectral method for the determination of trace amounts of Se.

A new catalytic kinetic method has been proposed for the determination of Se from 8.0x10(-9) to 8.0x10(-8) M, using the fact that Se(IV) can catalyze the slow reaction between KClO(3) and phenylhydrazine sulfate (PH) in 0.

Fluorescence optical fiber sensor for tetracycline.

A new optical fiber sensor for monitoring tetracycline has been described, based on the fluorescence quenching of 1,4-bis(5,5'-dimethylbenzoxazole-1',3'-yl-2')benzene incorporated into a thin plasticized polymer film by tetracycline extracted from aqueous phase into film phase. The sensor is fully reversible and highly reproducible. Furthermore, the sensor exhibits a linear response to tetracycline in the range 6.

Are cognitive biases associated with body image concerns similar between cultures?

This experimental investigation examined judgment and memory biases associated with body image concerns in American and Chinese young adult samples. In Study 1, 50 American university students (43 female, 7 males) screened into groups high and low in self-reported concerns about body size and weight engaged in a computer-based experiment involving the evaluation and later recognition of randomly presented fat and thin body words and matched control words. Participants high in reported body image concerns judged certain kinds of fat words more negatively and remembered them more accurately than individuals low in perceived body image disturbances.

Interaction of [HgX4]2- with berberine by absorption and resonance Rayleigh-scattering spectra and their analytical applications.

In a diluted H2SO4 solution, Hg(II) reacts with halide anions X- (including Cl-, Br- and I-) to form anionic complexes [HgX4]2- that can further react with berberine to form ion-association complexes of [Ber]2[HgX4]. As a result, the absorption spectra change, their maximum absorption wavelengths are at 230 nm for [Ber]2[HgCl4], 278 nm for [Ber]2[HgBr4] and 300 nm for [Ber]2[HgI4]. However, among the three complexes, only [Ber]2[HgI4] can lead to distinctly enhanced resonance Rayleigh scattering (RRS), and a new RRS spectrum appears.

Relationship between the antibacterial and immunological activities of houttuyfonate homologues and their surface activities.

Based on the microbial model (Staphylococcus aureus and Bacillus subtilis) and the experiment of mouse carbon granular clearance, the relationship between antibacterial and immunological activities of houttuyfonate (HOU) homologues and their surface activities were studied. The results showed that with elongating the carbon chain of HOU homologues, the surface activities and bacteriostasis and immunological activities would be increased. It is suggested that the pharmacological effect of HOU homologues could be realized by the hydrophobic interaction between HOU homologues and membrane proteins of bacteria and cell.

Resonance Rayleigh-scattering method for the determination of sildenafil citrate in a pharmaceutical formulation using Evans blue.

A highly sensitive resonance Rayleigh-scattering (RRS) method for the determination of sildenafil citrate has been developed, based on the fact that sildenafil (Sild) reacted with Evans Blue (EB) to form an ion-association complex in pH 1.1 - 4.6 aqueous solution.

[Microclimate edge effects of evergreen broad-leaved forest fragments in Jinyun Mountain: a preliminary study].

This paper studied the microclimate of continuous and fragmental evergreen broad-leaved forests in Jinyun Mountain by determining the horizontal gradient distribution of microclimate elements near forest edges. The results showed that there existed clear edge effects of microclimate in every edge of fragmental forests. The distinctions of maximum and minimum air temperature, photosynthetic active radiation, and minimum relative humidity between edge forest and interior forest were higher or greater, while that of maximum ground surface temperature was lower or smaller in dry season than in rain season.

A new chemiluminescence method for the determination of nickel ion.

A new chemiluminescence (CL) phenomenon described as the second-chemiluminescence (SCL) was observed and a strong CL signal was detected, when Ni(II) ion was injected into the mixture after the end of the reaction of potassium permanganate with alkaline luminol. The possible CL mechanism is proposed based on the kinetic curve of the CL reaction, CL spectra, UV-vis spectra and some other experiments. A flow-injection analysis for the determination of nickle(II) ion has been developed, based on the catalysis of nickel(II) ion on the CL reaction between potassium manganate produced on-line and luminol under alkaline condition.

Effects of dietary soybean protein levels on metabolic response of the southern catfish, Silurus meridionalis.

A closed respirometer was used to measure oxygen consumption of the southern catfish Silurus meridionalis fed with six isonitrogenous (48% crude protein) diets replacing 0%, 13%, 26%, 39%, 52% and 65% fish meal (FM) protein by soybean meal (SBM) protein, in order to investigate the effects of dietary soybean protein level (SPL) (replacing FM) on metabolic rates of the southern catfish. The results showed that there were no significant differences in routine metabolism among dietary treatments. Either the total metabolic rate or specific dynamic action (SDA) was positively correlated with assimilated food energy at each diet, respectively (P<0.

Fluorescence quenching method for the determination of sodium carboxymethyl cellulose with acridine yellow or acridine orange.

In near neutral to weak basic media, sodium carboxymethyl cellulose (NaCMC) will dissociate to become a macro polymeric anion, which can react with acridine yellow (AY) or acridine orange (AO) to form an ion-association complex resulting in fluorescence quenching of the acridine dyes. The maximum fluorescence quenching wavelength is 505 nm (lambda(ex)=440 nm) for AY system and 530 nm (lambda(ex)=493 nm) for AO system, respectively. The fluorescence quenching values (DeltaF) are directly proportional to the concentrations of NaCMC and the linear ranges are 20.

Ab initio computational insight into the ion-pair S(N)2 reaction of lithium isothiocyanate and methyl fluoride in the gas phase and in acetone solution.

The ion-pair S(N)2 reaction LiNCS + CH3F with two mechanisms, inversion and retention, was investigated at the MP2(full)/6-311+G**//HF/6-311+G** level in the gas phase and in acetone solution. All HF-optimized structures were confirmed by vibrational frequency analysis. Based on IRC analyses, eight possible reaction pathways in the title reaction are proposed.

[Temporal and spatial dynamics of reproductive modules of endangered plant Disanthus cercidifolius var. longipes natural populations].

Based on field observation data, this paper studied the flowering phenology and the temporal and spatial dynamics of the reproductive modules of endangered plant Disanthus cercidifolius var. longipes natural populations. The results showed that there were certain differences of the flowering phenology among the populations in different communities, e.

New amperometric and potentiometric immunosensors based on gold nanoparticles/tris(2,2'-bipyridyl)cobalt(III) multilayer films for hepatitis B surface antigen determinations.

Two generic, fast, sensitive and novel electrochemical immunosensors have been developed. Initially, a layer of plasma-polymerized Nafion film (PPF) was deposited on the platinum electrode surface, then positively charged tris(2,2'-bipyridyl)cobalt(III) (Co(bpy)(3)(3+)) and negatively charged gold nanoparticles were assembled on the PPF-modified Pt electrode by layer-by-layer technique. Finally, hepatitis B surface antibody (HBsAb) was electrostatically adsorbed on the gold nanoparticles surface.

[Soil enzyme activities of limestone degraded ecosystem at its different restoration phases].

The study showed that there was no distinct descending of enzyme activities along the soil profile of limestone degraded ecosystem, which were enhanced with progressive succession, and varied with vegetation characteristics, soil types, and soil enzyme properties. On the whole, soil enzyme activities enhanced in order of herb < Cupressuss funebris high forest< shrubbery, and under the same vegetation, limestone Cupressuss funebris high forest had higher soil enzyme activities than purple psammophytia. There was no significant correlation between soil enzyme activities and soil pH, while significant correlation was found between soil moisture content, soil total nitrogen content and soil enzyme activities, indicating that soil water and nutrient contents were the key factors of ecological restoration in this region.

A study on the sizes and concentrations of gold nanoparticles by spectra of absorption, resonance Rayleigh scattering and resonance non-linear scattering.

Liquid phase gold nanoparticles with different diameters and colors can be prepared using sodium citrate reduction method by controlling the amounts of sodium citrate. The mean diameters of gold nanoparticles are measured by transmission electron microscope (TEM). Gold nanoparticles with different sizes have specific absorption spectra.

A sensitive and simple method for the determination of chondroitin sulfate a with crystal violet by resonance rayleigh scattering technique.

Resonance Rayleigh scattering (RRS) spectra resulting from interaction between chondroitin sulfate A (CSA) and crystal violet (CV) have been investigated and applied to the determination of CSA. Though the intensity of RRS has proved very weak for CSA and CV, respectively, it can be greatly enhanced when both interact and form a supramolecular complex. A new RRS spectrum appears with a maximum scattering peak at 328 nm.

Permanganate-based chemiluminescence analysis of ferulic acid using flow injection.

A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with potassium permanganate in a nitric acid medium. A strong chemiluminescence signal was observed when ferulic acid was injected into an acidic potassium permanganate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 6.

Dermocystidium sp. infection in cultured juvenile southern catfish Silurus meridionalis in China.

A species of Dermocystidium was discovered on the skin and fins of reared southern catfish Silurus meridionalis Chen. The parasite only appeared and caused disease in juvenile catfish at a water temperature of 18 to 23 degrees C. Marked external macroscopical clinical signs of the disease were sluggish movement of the fish, and the appearance of white filiform dermal cysts varying in size (3-20 mm in length and 0.

Effects of dietary soybean protein levels on energy budget of the southern catfish, Silurus meridionalis.

Energy budgets were calculated for the southern catfish, Silurus meridionalis, fed diets replacing 0%, 13%, 26%, 39%, 52% and 65% fish meal protein with soybean meal (SBM) protein with or without methionine supplementation to apparent satiation at 27.5 degrees C. With increasing dietary soybean protein levels (SPL), the feed energy lost in feces, excretion and metabolism increased, while that available for growth decreased (P<0.

Resonance Rayleigh scattering study of interaction of hyaluronic acid with ethyl violet dye and its analytical application.

In near weak acid to neutral medium, ethyl violet (EV) can react rapidly with hyaluronic acid (HA) to form a complex, which results in a significant enhancement of resonance Rayleigh scattering (RRS) and an appearance of a new spectrum, and the scattering wavelengths appear at 231, 274, 326, 498 and 640 nm. The maximum scattering wavelength appears at 326 nm. The RRS intensity is directly proportional to the concentration of HA in the range of 0.

[The dependability and safety of biomaterials and medical devices].

This article describes emphatically the dependability, safety and their guarantee measures for biomaterials and medical devices.