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“In this research, a new flexible polyimide (PI) foams was successfully prepared and characterized based on precursor
powder foaming. This foams were derived from 3,3′,4,4′-oxydiphethalic anhydride (ODPA), 3,3′, 4,4′-oxydiphethalic tetraacid (ODPA-tetraacid), and 4,4′-oxydianiline (4,4′-ODA). this website With varying molar percentage of ODPA-tetraacid in (ODPA vertical bar ODPA-tetraacid), the changes of properties of PI precursor powders and PI foams were comparatively investigated. The foaming processes of PI foams were observed by a self-made visualization device. The decomposition products of precursor powders were analyzed by thermogravimetry- Fourier transform infrared spectroscopy (TG-FTIR). The crystallinity of precursor powders was investigated by wide-angle X-ray diffraction (WXRD). The chemical structure of PI precursor powders and foams was analyzed by FTIR. The thermal properties of PI foams were tested by the methods of dynamic mechanical analysis (DMA), and TG/differential thermogravimetry (DTG) analysis. The cell structure of PI foams was observed by a scanning electron microscopy. The rebound resilience of PI foams was studied by a self-made drop-ball instrument. With the increasing of ODPA-tetraacid, the inflation onset temperatures and inflation degrees of PI foams decreased from 210 degrees C to 118 degrees C and increased from 10 to 14.8 times, respectively. CAL-101 chemical structure The crystallinity
of PI precursor powders increased. The thermal stability of PI foams decreased. The cell structure of PI foams became more uniform and the rebound rates increased linearly. Besides, ODPA-tetraacid did not yield any negative effect on the complete imidization of the PI precursor powder by the FTIR spectra. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3253-3263, 2011″
“Study Design. Review of the available literature, authors’ opinion.
Objective. To review the literature
on minimally invasive lateral approach for interbody fusion in treatment of adult deformity. To describe the key points of pertinent surgical anatomy and outline the results of our experience with Bucladesine nmr this technique.
Summary of Background Data. Minimally invasive surgery in the management of adult spinal deformity has been introduced to minimize the postoperative morbidity and facilitate earlier recovery in a group of medically fragile patients.
Methods. Literature review.
Results. Both patient-centered outcome measures (including Oswestry Disability Index, Visual Analogue Scale, and SRS-22) and objective results (correction of coronal and sagittal deformity) are significantly improved in most studies. Reported complication rates differ from one study to another but major complications are low. Infrequent neurologic complications occurred; however, most surgical sequelae were transient and had resolved at later follow-up.