Electrospun Mussel-derived Silk Fibers.

Background: Though there are many patents on silk, patents on sea silk are rare. Sea silk is one of the most coveted materials in the world, and the technology to make sea silk is at an extremely high risk of extinction. Unlike spider dragline silk and silkworm silk, this natural silk has been forgotten in the academic commune for millennia, though it has many fascinating properties: high strength, remarkable adhesion, extreme lightweight, and others.

WO3-x Nanoplates Grown on Carbon Nanofibers for an Efficient Electrocatalytic Hydrogen Evolution Reaction.

The search for non-noble metal catalysts with high activity for the hydrogen evolution reaction (HER) is crucial for efficient hydrogen production at low cost and on a large scale. Herein, we report a novel WO3-x catalyst synthesized on carbon nanofiber mats (CFMs) by electrospinning and followed by a carbonization process in a tubal furnace. The morphology and composition of the catalysts were tailored via a simple method, and the hybrid catalyst mats were used directly as cathodes to investigate their HER performance.

[Planktonic Algae's Distribution and Correlation with Dissolved Organic Matters' Fluorescence in the End of the Three Gorges Reservoir's Back Water Zone].

For researching the community structure, composition, and distribution of the planktonic algae in the Three Gorges Reservoir (TRG), especially, within TRG water levels' fluctuating, mpacting to water quality with the algae's growing, 6 sampling cites in the end of the TGR's back water zone, from Chaotianmen to Taihonggang Town, are chosen to monitor, at the sensitive stages time of algal bloom between March to May 2012, namely, water levels lowing from the highest impounding. The community's structure, composition, and distribution of the planktonic algae in the TGR, and the correlation of water quality parameters and DOM's fluorescence features with algae density, are obtained. According to the experimental results, blue algae fibre, chlorella, melosira, navicula are the dominated algae in the end of the TGR's back water zone, from Chaotianmen to Taihonggang Town, algae density are 0.

Improved oral bioavailability of breviscapine via a Pluronic P85-modified liposomal delivery system.

Objectives: Breviscapine, a hydrophobic drug used for treating cardiovascular disease, was encapsulated in liposomes to improve its pharmaceutical characteristics. This study describes a novel liposome composition approach to specifically inhibit the P-glycoprotein efflux system.

Methods: Breviscapine-loaded Pluronic P85-coated liposomes were prepared by the thin film hydration technique.

[Simultaneous determination of heavy metals in waste and biogas slurry of scale farm by microwave digestion/inductively coupled plasma-mass spectrometry].

A new microwave digestion/inductively coupled plasma mass spectrometry (ICP-MS) for simultaneous determination of 8 heavy metals including Zn, Cu, As, Pb, Cd, Cr, Hg and Ni in wastes of scale hoggery from livestock parks in Chongqing and its biogas slurry after anaerobic digestion, with which an all round, fast analysis of multiple heavy metals in biogas slurry was realized. From the experiment, Zn, Cu, As, Pb, Cd, Cr, Hg, and Ni were the dominating heavy metals in biogas slurry. The linear correlation coefficients for the heavy metals were between 0.

[Combined application of multiple fluorescence in research on the degradation of fluoranthene by potassium ferrate].

The degradation of fluoranthene was researched by combined means of multiple fluorescence spectra, including emission, synchronous, excitation emission matrix (EEM), time-scan and photometry. The characteristics of the degradation and fluoranthene molecular changes within the degradation's process were also discussed according to the information about the degradation provided by all of the fluorescence spectra mentioned above. The equations of fluoranthene's degradation by potassium ferrate were obtained on the bases of fitting time-scan fluorescence curves at different time, and the degradation's kinetic was speculated accordingly.

[Research on the degradation of BaP with potassium ferrate characterized by fluorescence].

The degradation of Benzo(a)pyrene (BaP) by potassium ferrate was researched by means of multiple fluorescence spectroscopic methods such as synchronous, time-scan, excitation emission matrix (EEM) and photometry, under the optimal condition. Within the degradation process, the characteristics of the BaP's concentration at different time-intervals, and the kinetics of the degradation of BaP by potassium ferrate were discussed. From the experimental data, both synchronous and EEM spectra's results showed that the concentration of BaP was reduced 90% by potassium ferrate within 20 s after degradation, and the reaction process was very slow after 60 s.

[Function of luxS gene in sulfurmetabolism of Streptococcus mutans].

Objective: To investigate the function of luxS in sulfurmetabolism of Streptococcus mutans (Sm).

Methods: The growth with absorbency (A) of the standards and mutant strains was measured and analyzed in the sulfur-limited defined medium at different periods. The laser scanning confocal microscopy (LSCM) was used to observe and compare the biofilm thickness of the two kinds of strains at different culture conditions.

[Application of Cre-loxP(*) system in constructing the markerless double-gene-deletion strain in Streptococcus mutans].

Objective: To construct double gene deletions at the htrA and clpP loci on the chromosome of Streptococcus mutans (Sm) and to remove the antibiotic resistance markers with the Cre-loxP(*) site-specific recombination system.

Methods: The htrA gene was cloned into the pGEM-T-Easy TA cloning vector and then inactivated via the insertion of a kanamycin resistance cassette (lox71-Km-lox66), yielding pGEM-T-ΔhtrA/Km for deleting the htrA gene. Using the same method, the pGEM-T-ΔclpP/Sp was constructed for deleting the clpP gene.

[The study of dimethoate by means of vibrational and surface enhanced Raman spectroscopy on Au/Ag core-shell nanoparticles].

The vibrational structure of dimethoate, with its solid state and saturated solutions at acidic and basic conditions, was characterized with combination of means of FTIR and FT-Raman vibrational spectroscopy technology, and the comprehensive information about the dimethoate molecular groups' vibrational features was obtained. The surface enhanced Raman scattering (SERS) spectra of dimethoate at different concentrations with different acidic and basic conditions, and adsorbed on the substrate's surface of the core-shell Au/Ag nanoparticles, were also obtained. The adsorption states of dimethoate's molecule on the substrate's surface of the core-shell Au/Ag nanoparticles and the effects by the different acid-base conditions were investigated, with speculation of the adsorption mechanism.

[Study of vibrational spectra of humic substance in soils from the three Gorges Reservoir Area].

The six typical different parts of soils and sediments along the bank of the Three Gorges Reservoir Area (TGRA) were collected, and the humic substance isolated from the six parts of the soils and sediments' samples was separated to humic acid and fulvic acid, purified, and characterized with the combination of the Raman and IR vibrational spectroscopic technologies after cool-dried separation; through assigning the vibrational peaks in each part of the Raman and IR spectra of each sample part, the vibrational characteristics of the structures and the groups that belonged to the molecules of the humic acids and the fulvic acids in the soils and sediments of the TGRA were obtained; the changing features of the groups and structures in the humic acid and the fulvic aicd's molecules from the different soils and sediments in the TGRA were discussed with the environmental impact factors such as soil humic degree, the conditions of different soils conference, using and/or cultivating models and water level fluctuations. From the experimental results, the vibrations about C-O, C-C, and poly-hydrogen bonds dominate in the structures and the groups of each part' humic substance; the active vibration numbers in the upstream are more than in the downstream; the soil's humic degree has great effect on the formation of the humic substances' structures in soil's humic substance; the soil used as agricultural cultivating mode showed higher humic degrees in the upstream parts of the TGRA. The effect of the water level's fluctuation on the formation of the humic acid and fulvic aicd in the sediments of the TGRA is not obvious in the short time.

[Study of the fluorescence characteristics of DOM from the Yangtze River and Jialing River around Chongqing's urban areas].

The fluorescence emission and excitation emission matrix (EEM) technologies were used to characterize the dissolved organic matter (DOM) in the water body of the Yangtze River and Jialing River around the Chongqing urban areas from April to August 2008. Concerning about the accidents of the Wenchuan's Earthquake in May and Tangjiashan Yansaihu's effects in June, and the high water period time in the summer in two months of July and August, from the EEM obtained from each sampling station and time, the composition, distribution and their changing features of the DOM in the two rivers were investigated as combined with the water samples' environmental parameters such as pH, DO, DOC with EEM's fingerprint features, f(450/500) etc; finally the bio-environment behavior effects of the three types of fluorescence peaks were elaborated, where humic-like, fulvic-like, and protein-like from the five sampling stations' EEMs during the five months were given detailed representation. From the experimental results obtained, the fluorescence peaks are mainly composed of two types of fluorophores: humic-like and protein-like in the two rivers around the Chongqing urban areas during the investigation in five months, the protein-like's peaks value in Jialing River is higher than the values in the Yangtze River, and all the fluorescence peaks in the two Rivers' water body decrease more or less after the two Rivers join in Chun Tan sampling station; the protein-like peak is notably higher after the "5 x 12" earthquake period time including May and June and high water period time, which mainly originated from terrestrial sources, but its intensities decreased observably while the water bodies of the two rivers joining together in the Chao Tianmen and Chun Tan's sampling station.

[Study on the interaction of DNA and norfloxacin by FT-Raman].

FT-Raman and surface enhanced Raman spectra (SERS) of norfloxacin and norfloxacin capsule on the silver colloidal substrate were recorded, and the vibrational and enhanced peaks were assigned; interactions of norfloxacin and DNA were researched. The experimental results proved that the characteristic vibrations of capsule's content and NFX standard, which is v(C-F), vs(O-C-O), v(C=C), did not change, while the changes in molecular skeleton's vibrations were substantial. Additives do not affect the Raman spectroscopy of norfloxacin substantively.

[FTIR, FT-Raman and surface enhanced Raman study of shikimic acid].

The authors reported the FT-infrared, and FT-Raman spectra of shikimic acid in solid state and in saturated liquid state in the present article. The vibrational peaks of each group in the molecular structure of shikimic acid were obtained and assigned, and furthermore, the Raman and IR vibrational shifts of the corresponding groups in the molecular structure of shikimic acid were analyzed and speculated especially. As shikimic acid mixed with silver nanoparticle the SERS-active substrate, and was adsorbed on the surface of the silver nanoparticle, we also obtained the surface enhanced Raman scattering (SERS) spectra of shikimic acid at different concentrations from 1.

[Enriching of total flavonoids from Herba Leonuri with polyamide and macroporous resin].

Objective: To study the enriching method of total flavonoid from Herba Leonuri with polyamide and macroporous resin.

Method: Seven enriching and purifying methods were compared with the yield and purity as indexes. The method of enriching with polyamide and macroporous resin was confirmed and the process of purifying was determined by orthogonal design.

[Detection of quorum-sensing pathway and construction of luxS gene allelic exchange plasmid of Streptococcus mutans].

Objective: To detect the AI-2 quorum-sensing pathway and construct the luxS g-ene allelic exchange plasmid of Streptococcus mutans.

Methods: To detect AI-2 pathway in Streptococcus mutans, the Vibrio harveyi BB170 was used as reporter strain. The PCR fragments of the upstream and downstream regions of luxS and the Erythromycin resistance gene were amplified with the primers respectively, and these fragments were ligated into pUC19 vector with double endonuclease reaction sequentially, the ligated DNAs were transformed into Escherichia coli DH5alpha, then the reconstructed plasmids were isolated and identified by restricted endonuclease digestions.

[Study on adsorption of nonpolar R-side amino acids on silver nanoparticles by FT-SERS].

The adsorption orientation and adsorption characteristics of aliphatic-nonpolar amino acids represented by L-methionine on silver nanoparticles were studied by FT-surface-enhanced Raman spectroscopy (FT-SERS) method with different pH and concentrations. According to the experiments, in order to get the best FT-SERS effects, the optimal concentration range of the L-methionine on silver sol is between 10(-3) mol x L(-1)-10(-4)(mol x L(-1). The FT-SERS effects and adsorption model change with pH; The SERS are poor when pH is near the isoelectric point or over 11 or 3.