Understanding the mechanisms by which EBV induces cellular signal transduction pathways may MLN2238 ic50 facilitate development of new treatments for PTLD.”
“Graft copolymerization of different vinyl monomers onto chitosan (Cs) and its derivatives can alter their properties and consequently expands their potential applications. In this study, carboxymethyl chitosan (CMCs) was prepared and
characterized. Graft copolymerization of acrylic acid sodium salt (AAs) onto CMCs was accomplished by using ammonium persulphate (APS)-induced free radical polymerization in aqueous medium under nitrogen atmosphere. Occurrence of grafting was confirmed and the effects of [AAs], [APS], reaction time, and temperature on the extent of grafting were studied. The influence of grafting yield on the structure and dynamics
was also investigated by using differential scanning calorimetry (DSC), two-dimensional wide-angle X-ray scattering (2D-WAXS), scanning electron microscopy (SEM), and dielectric spectroscopy. Preliminary study, using dielectric spectroscopy, was carried out to the CMCs-g-AAs copolymer with grafting percent similar to 2900%, as an example, in a wide range of temperature (from 299 to 473 K) and frequency (from 1 x 10(-2) to 1 x 10(5) Hz). One relaxation process with Selleckchem BEZ235 Arrhenius type was detected. This process has the characteristics of a secondary relaxation process related to local chain dynamics with activation energy of 53 +/-. 3 kJ/mol. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 2134-2145, 2010″
“Study Design. Biomechanical investigation of primary and revised cement-augmented
pedicle screws in comparison with unaugmented screws.
Objective. To evaluate revision of cannulated pedicle screws and investigate cement-augmented and nonaugmented screws biomechanically, testing the torque of primary screws and axial pullout force of revised screws in cadaver vertebrae.
Summary of Background Data. Cement augmentation increases the pullout force and stability of pedicle screws in vertebrae with low bone mineral density, but surgeons are concerned about complications during revision.
Methods. Bone mineral density Selleckchem ATM/ATR inhibitor was measured using quantitative computed tomography (CT) in 23 osteoporotic thoracolumbar junction vertebrae from human cadavers. Cannulated pedicle screws, augmented with bone cement (on right) or unaugmented (left), were inserted into each vertebra. After CT control, extraction torque was measured and the pedicles were reinstrumented with larger-diameter screws. The right screws were augmented again, with another CT control, before pullout testing.
Results. Mean vertebral bone density was 52.6 mg/cm(3). No major screw malpositioning was observed on primary CTs. Cement leakage was observed anterolaterally and into the spinal canal. Mean maximal torque in augmented screws (1.2 Nm, SD: 0.