Poly (p-phenylene vinylene) (PPV) was synthesized from p-xylylene bis(tetrahydrothiophenium chloride) using the Wessling route and characterized by Fourier Transform Infra-Red (FTIR) and UV-visible (UV-VIS) spectroscopic techniques. The significance of thermal treatment along with evolution of precursor polymer to polymer PPV was also studied through these spectroscopic techniques. Thermally Stimulated Current (TSC) measurements indicated the presence of crystallization, sulphonium group which occurred through the evolution from precursor polymer to polymer PPV during thermal treatment.
Polymers/analysis ; Polymers/*chemical synthesis ; Polyvinyls/analysis ; Polyvinyls/*chemical synthesis ; Spectroscopy, Fourier Transform Infrared

To compare two enrichment and preservation methods of urinary proteins, stored in polyvinylidene difluoride (PVDF) membrane (Urimem) or direct freezing, we examined the differences between the two methods in time, space, costs of supplies and electricity, degree of protein degradation and convenience of the sample handling. The urimem method is superior in the storage space, the cost of electricity and the clinical convenience compared to the direct freezing method. However, the direct freezing method is superior in the time and the cost of supplies to the urimem method. The enrichment and preservation of urinary proteins using urimem have more cost-effective benefits compared to those of the direct freezing method.
Cost-Benefit Analysis ; Freezing ; Humans ; Polyvinyls ; Preservation, Biological ; methods ; Proteins ; chemistry ; Urine ; chemistry

The low abundance and highly hydrophobic nature of most membrane proteins make their analysis more difficult than that for common soluble proteins. Successful membrane protein identification is largely dependent on the sample preparation including the enrichment and dissolution of the membrane proteins. A series of conventional and newly developed methods has been applied to the enrichment of low-abundance membrane proteins at membrane and/or protein levels and to the dissolution of hydrophobic membrane proteins. However, all the existing methods have inherent advantages and limitations. Up to now, there has been no unique method that can universally be employed to solve all the problems and more efforts are needed in improving sample preparation for the analysis of membrane proteomes.
Chromatography, High Pressure Liquid ; Mass Spectrometry ; Membrane Proteins ; analysis ; metabolism ; Membranes, Artificial ; Oxidation-Reduction ; Polyvinyls ; chemistry ; Proteome ; analysis ; Proteomics

OBJECTIVETo compare the mechanical properties of different dental optimal material selection for orthodontic appliance.

METHODSFour commercialized thermoplastic products under different test conditions, and provide the suggestion of thermoplastic products were tested. The tear strength, elongation at break and stress relaxation of these materials were measured under different test conditions.

RESULTSThe tear strength declined after thermoforming, and rose again after 2 weeks of distilled water immersion. The elongation at break rose after thermoforming, and declined after 2 weeks of distilled water immersion. No significant changes were observed for brand A under different test conditions. Brand A showed the slowest stress relaxation of 0.0148 N/s.

CONCLUSIONSThe mechanical properties of thermoplastic materials were influenced by environmental factors. Brand A exhibited optimal comprehensive properties.

Analysis of Variance ; Dental Materials ; chemistry ; Hot Temperature ; Materials Testing ; Orthodontic Appliances ; Polyethylenes ; chemistry ; Polyvinyls ; chemistry ; Shear Strength ; Stress, Mechanical

High selectivity provided by biomolecules such as antibodies and enzymes has been exploited during the last two decades for development of biosensors. Of particular importance are efficient immobilization methods for biomolecules in order to preserve their biological activities. In this study, we have evaluated immobilization strategies for an anti-DNA antibody on a self-assembled monolayer of omega-functionalized thiols. The antibody was immobilized via peptide bond formation between the primary amines in the antibody and the carboxyl groups on the self-assembled monolayer. The peptide bond coupling was achieved by activating COOH groups on the surface through N-Hydroxysuccimide (NHS)-ester formation, followed by acylation of NH2 group in the antibody. DNA binding activity of the immobilized antibody was examined by counting beta emission from 35S-labeled DNA.
Antibodies, Antinuclear* ; DNA/immunology ; DNA/analysis* ; DNA-Binding Proteins/chemistry ; Gold ; Membranes, Artificial ; Polymerase Chain Reaction ; Polyvinyls/chemistry ; Radioimmunoassay/methods* ; Thioctic Acid/chemistry

PURPOSE: We'd like to know the relationship between the changes of cardiac function and systemic O2 consumption according to the increasing dose of dopamine. METHODS: Ten rabbits(from 2kg to 2.8kg) were used in this experiment. Anesthesia was induced with intraperitoneal pentobarbital sodium(35mg/kg) and tracheostomy was done. It was maintained by ventilation with a mixture of 1-3% halothane and 67-69% oxygen. Polyvinyl catheters were inserted into the femoral artery and vein and to check blood pressure and arterial blood gas analysis during the surgical procedure. Two other catheters were inserted into the internal carotid artery and external jugular vein and advanced into left ventricle and right atrium to check the pressure of each chamber, LV maximal dP/dt and to obtain blood samples of each chamber. Thoracotomy was done to expose aorta and coronary artery to check the cardiac output and coronary blood flow. We injected dopamine every 10 minutes according to the scheduled dose through external jugular vein and recorded heart rate, cardiac output, aortic pressure, maximal dP/dt, coronary blood flow by computer. Systemic O2 consumption was calculated by Fick method RESULTS: The heart rate and mean aortic pressure increased slowly according to the dose of dopamine from 20 microgram/kg/min. The cardiac otuput the maximal dP/dt and coronary blood flow was not changed until 5 microgram/kg/min, but from 7.5microgram/kg/min, it increased according to the dose of dopamine. CONCLUSION: Dopamine was a powerful inotrophic agent without increasing the systemic O2 consumption until 20microgram/kg/min, but systemic O2 consumption increased markedly at more than 20 microgram/kg/min of dopamine.
Anesthesia ; Aorta ; Arterial Pressure ; Blood Gas Analysis ; Blood Pressure ; Cardiac Output ; Carotid Artery, Internal ; Catheters ; Coronary Vessels ; Dopamine* ; Femoral Artery ; Halothane ; Heart Atria ; Heart Rate ; Heart Ventricles ; Jugular Veins ; Oxygen Consumption* ; Oxygen* ; Pentobarbital ; Polyvinyls ; Thoracotomy ; Tracheostomy ; Veins ; Ventilation