A new species of Svistella Gorochov, 1987 from Xizang, China (Orthoptera, Trigonidiidae, Trigonidiinae).

The genus Svistella Gorochov, 1987 includes 10 species from Asia, with nine documented in China. In this study, a new species, Svistellayayun He, sp. nov., is described from Xizang, China. Morphologically, it resembles S.rufonotata (Chopard, 1932) but can be distinguished by a smaller inner tympanum, dark-brown setae on the 5th segment of the maxillary palp, and a rounded apex on the ectoparamere. To validate our morphological inferences and support the description of S.yayunsp. nov. as a new species, we performed a PCA based on bioacoustics parameters and molecular analysis. All Svistella species documented in China are distinguished by integrating their songs and DNA barcoding.

Evaluation of two polymeric blends (EVA/PLA and EVA/PEG) as coating film materials for paclitaxel-eluting stent application.

The ethylene vinyl acetate copolymer (EVA)/Poly (lactic acid) (PLA) blend and EVA/Poly (ethylene glycol) (PEG) blend were applied as the drug carrier materials for a bi-layer drug-loaded stent coating film, which consisted of a paclitaxel (PTX)-loaded layer and a drug-free EVA layer. The changes of weight and appearance of the drug-free polymeric blend films with increasing time were examined by X-ray diffraction analysis (XRD), gel permeation chromatography (GPC) tests and scanning electronic microscopy (SEM), and the results showed the degradation of PLA and the leaching of PEG from the films. The effects of PLA, PEG and drug contents on in vitro drug release were investigated, and the results demonstrated that the addition of PLA promoted the drug release while the addition of PEG almost did not. Franz cells diffusion test results indicated that the bi-layer structure successfully endowed the stent coating with the release of drug in a unidirectional fashion. The release profiles of films incorporated PTX and the mechanical performance of the film could be customized by readily adjusting the contents of the blend components. Therefore, the polymeric blends could be useful drug carrier materials for drug-loaded stent coating capable of releasing drug in a highly tunable manner.

[Investigating Adsorption of Naphthalene to Organo-Modified Montmorillonites and Influencing Factors].

There are many sites contaminated by polycyclic aromatic hydrocarbons (PAHs) or combined PAHs-heavy metal in China, which pose serious health-risks to local people and environments. Dissipative quartz crystal microbalance (QCM-D) was applied to investigate the adsorption of naphthalene to two organic-modified smectite clays (cetyltrimethyl ammonium bromide modified montmorillonite, CTAB-SMF, and 3-mercapto propyl trimethoxy silane modified montmorillonite, TMSP-SMF) and original SMF, together with batch adsorption experiments. The results, based on in-situ online QCM-D experiments, showed that the adsorption sites of CTAB-SMF on naphthalene were mainly CTAB grouped between the interlayers of clay particles, while TMSP-SMF's were TMSP grouped on the surfaces of clay particles. The isotherms of naphthalene adsorption to CTAB-SMF fitted well (R2>0.92) with the Freundlich model, while the adsorption isotherms to TMSP-SMF and SMF fitted well with the Langmuir model (R2>0.96). The parameters of CTAB-SMF (n>1) indicated that the adsorption sites of naphthalene to CTAB-SMF were heterogeneous and the adsorption increases at higher equilibrium concentration. The adsorption capacity qmax of TMSP-SMF is significantly greater than that of SMF (P<0.05). Based on the calculation, the value of ΔHobs for these three clays (CTAB-SMF, TMSP-SMF, and SMF) were within the range of -30 to -10 kJ·mol-1, which indicated that it was a spontaneous exothermic physical process. The solution ionic strength could decrease the adsorption of naphthalene to SMF, but had limited effects on naphthalene adsorption to the two organo-modified clay particles. The existence of Cu2+ in the solution could enhance naphthalene adsorption to the three particles, and naphthalene could improve Cu2+ adsorption to these two modified clays. The results of this study show that QCM-D is a useful technique to indicate the changes of clay film during the process of adsorption, and the two organo-modified clay particles have the potential to be remediation materials to remediate PAHs or PAHs-heavy metal-contaminated sites.

Treatments of paclitaxel with poly(vinyl pyrrolidone) to improve drug release from poly(ɛ-caprolactone) matrix for film-based stent.

Drug-loaded biodegradable films as a principal part of film-based stent were investigated for controlled drug delivery systems. In this study, solid dispersion technique, a pretreatment method of paclitaxel (PTX), was applied to prepare the PTX-loaded poly(ɛ-caprolactone) (PCL) films. Drug dissolution rates and characteristics of the poly(vinyl pyrrolidone) (PVP)/PTX solid dispersions (SDs) and physical mixtures (PMs) were investigated to show that the PVP/PTX SDs were successfully prepared before being incorporated in biodegradable films. Afterwards, the effect of the application of SDs on improving drug release behavior, weightlessness, crystalline states, and surface and internal morphologies of the films were studied. It was found that, the films with SDs showed a higher drug release rate than the films with PMs or pure PTX. In addition, the content of PVP in the SDs also had impact on drug release behavior: the more PVP in SDs, the faster the drug was released. According to the drug release test and weightlessness study, the possible drug release mechanism was put forward for the films with SDs. The application of solid dispersion technique showed a remarkable effect on improving drug release behavior for film-based biodegradable stent drug delivery systems.

Effects of amphiphilic PCL-PEG-PCL copolymer addition on 5-fluorouracil release from biodegradable PCL films for stent application.

Biodegradable film-based stents emerged as a promising medical platform for drug delivery to resolve stenosis encountered in physiological conduits (e.g. blood vessels, biliary and urethral tracts). Drug release kinetics significantly affects the pharmacological effects of a stent, thus it is desirable for a stent to possess highly adjustable drug release kinetics. In this study, a series of amphiphilic poly(ɛ-caprolactone)-poly(ethylene glycol)-poly(ɛ-caprolactone) (PCL-PEG-PCL) copolymers were used as additives to adjust 5-fluorouracil (5-FU) release from PCL films. The effects of the copolymer addition on drug release behavior, drug permeability, crystalline states, and surface and internal morphologies of the films were investigated. It was found that, the addition of PCL-PEG-PCL could accelerate 5-FU release. The release rate of 5-FU increased with increasing content of PCL-PEG-PCL in the film, but it decreased with the ratio of PCL blocks in the PCL-PEG-PCL copolymer. The diffusion test results showed that 5-FU diffused through the film containing PCL-PEG-PCL faster than it permeated through the pure PCL film, indicating that the addition of PCL-PEG-PCL can improve the permeability of 5-FU in PCL film. The addition of PCL-PEG-PCL copolymer showed high drug-release-regulating ability in the 5-FU-loaded PCL films.