Regulation of fertilization in male rats by CatSper2 knockdown

Interest in ion channels as drug targets for contraception has grown with the realization that certain ion channel subunits are located exclusively in sperm. Selective knockdown of ion channel subunits can lead to infertility without ill effects, and selective inhibitors and/ or openers of these ion channels could interfere with sperm function. In this study, in vivo electmporation （EP） and rete testis microinjection-mediated plasmid DNA were adopted to silence CatSper2 expression, which is essential in sperm hyperactivation. The results showed that high transfection efficiency and expression were achieved by plasmid DNA that was directly injected into the rete testis. As a result of the expression of CatSper2 being blocked, the treatment group showed significantly lower （P〈0.05） hyperactivation rate, fertilization rate in vitro, migration motility in viscoelastic solution and intracellular Ca2＋ peak. The low hyperactivation and fertilization rates lasted for 60 days. Meanwhile, analysis of the sperm survival rate and testis histology indicated that in vivo EP had no significant effect on the function of the testis, spermatogenesis or sperm activity. The present study demonstrated that it was feasible to achieve male contraception by silencing the expression of CatSper2, the key protein involved in sperm hvoeractivation.

MORPHOLOGY AND PROPERTIES OF LINEAR LOW-DENSITY POLYETHYLENE HIGHLY LOADED WITH ALUMINUM HYDROXIDE

An experimental study was carried out to investigate the effects of isopropoxy tri(dioctyl pyrophosphoryl) titanate coupling agent on the mechanical performance, rheological property and microstructures of polyethylene highly loaded with aluminum hydroxide (Al(OH)(3)) composite, It was found that the addition of coupling agent results in reduced tensile strength and increased percentage elongation of the filled systems. Silane crosslinkable polyethylene substituting for polyethylene as matrix improves the tensile strength of the composite, while the percentage elongation of the composite still remains at a desired level. Melt viscosity of the composite will be improved by addition of titanate coupling agent. Microstructures of the composites were also studied by means of the scanning electron microscopy (SEM) technique. SEM micrographs reveal that finer dispersion of Al(OH)(3) will be obtained upon treatment of titanate and a transition from brittle to tough fracture takes place before and after silane crosslinking structure is introduced into polyethylene highly filled with Al(OH)(3) composite.

MODIFICATION OF POLYETHYLENE BY in situ FORMED SODIUM ACRYLATE

To improve the water tree resistance of PE, linear low-density polyethylene （LLDPE） was compounded with sodium acrylate （NaAA） for in situ polymerization, in which NaAA was fbrmed through the neutralization of acrylic acid （AA） with sodium hydroxide （NaOH） before adding dicumyl peroxide （DCP） to initiate the in situ graft polymerization and homo polymerization. A series of LLDPE/NaAA compounds were investigated for their water absorption ratio （WAR） measurement, water treeing, mechanical and dielectric properties. The results strongly suggest that NaAA can improve the water tree resistance of LLDPE. In addition, the LLDPE/NaAA compounds possess satisfactory mechanical properties and dielectric properties. Characterization of LLDPE/NaAA compounds by using Fourier transform infrared spectrometry （FTIR） suggests that the neutralization and polymerization reaction could be achieved effectively. Using adequate DCP content is the key factor for controlling the polymerization of NaAA with precise conversion ratio.

STUDY ON THE MORPHOLOGY OF POLYVINYL CHLORIDE/POLYSTYRENE BLENDS BY ELECTRON MICROPROBE ANALYSIS

The morphology of polyvinyl chloride/polystyrene (PVC/PS) blend samples with different mass ratios, prepared by means of solution casting and melt mixing, have been successfully examined by electron microprobe analysis (EMP). This experiment was performed in a scanning electron microscope attached to an energy dispersive X-ray analyzer. Differential scanning calorimetry was also used to investigate the phase separation of the blends. The results show that PVC and PS are incompatible and the blends have sea-islands phase structures. Blends prepared via melt mixing have finer phase-dispersion than those prepared via solution casting.

Manufacturing and characterizing of CCTO/SEBS dielectric elastomer as capacitive strain sensors

Calcium copper titanate(CCTO)/polystyrenepolyethylene-polybutylene-poly styrene(SEBS)dielectric elastomers were prepared via blending method.A capacitive strain sensor using CCTO/SEBS as dielectric layer and polyaniline-dodecylbenzensulfonic acid(PANI-DB S A)/SEBS as electrodes was designed and manufactured by thermoforming process.X-ray diffractometer(XRD),scanning electron microscopy(SEM)and Raman spectra analyses were carried out;no impurities were found in the composite and CCTO particles were well dispersed.The dielectric tests showed that the samples filled with 20 wt%CCTO have their permittivity improved by 70%.The capacitive strain sensors have a stabilized capacitance variety range at different strain ranges or stretch speeds,and could remain synchronized after 500-time-stretching,showing high reproducibility.

Percutaneous kyphoplasty in the treatment of Kümmell disease in lumbar scoliosis:A case report

BACKGROUND Due to mechanical imbalance in the spine,elderly scoliosis patients tend to develop vertebral fracture nonunion,i.e.,Kümmell disease,when osteoporotic vertebral compression fractures occur.However,accompanying vertebral rotational deformities make surgical procedures challenging risky.Such patients are usually compelled to undergo conservative treatment and there are very few reports on minimally invasive surgeries for them.We first-time report a patient with Kümmell disease and lumbar scoliosis treated with percutaneous kyphoplasty(PKP)under O-arm guidance.CASE SUMMARY An 89-year-old female was admitted to the hospital due to delayed low back pain after a fall.She was diagnosed with Kümmell disease based on physical and radiologic examinations.The patient experienced severe scoliosis and subsequently underwent O-arm-guided kyphoplasty,resulting in a significant alleviation of low back pain.CONCLUSION PKP has good efficacy in treating Kümmell disease.However,surgical risks are elevated in scoliosis patients with Kümmell disease due to the abnormal anatomical structure of the spine.O-arm assisted operations play a crucial role in decreasing surgical risks.

Design and properties of calcium copper titanate/poly(dimethyl siloxane) dielectric elastomer composites

The high phase content of inorganic dielectric fillings will give a strong electric driving force and hard matrix. That is a contradiction in enhancing the electrodeformation of dielectric elastomers(DEs). Therefore, in this paper, by focusing on how to approach a balance between these and finding an effective way to tune the electric response of the DEs, the theoretical calculation and experimental investigation based on calcium copper titanate(CCTO)/poly(dimethyl siloxane)(PDMS) were carried out. It is found that CCTO with a smaller particle size shows a larger dielectric parameter. With smaller CCTO particle as the fillings, the fabricated elastomer composite would approach to a low modulus by a proper CCTO phase morphology in the matrix.