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hydrogen bonding between PEG and water increases solubility of the MBP. At neutral pH, the increased degree of ionization of the carboxylic acid groups makes the system soluble. In the intermediate pH range of 4±6, where the two opposing forces are balanced, the system seems to have minimal solubility and forms a gel phase. This is similar to the solubility of insulin, which is minimal at pH 4.5±5.5, where ionization of amino groups (positively charged) and carboxylic acid groups (negatively charged) are balanced to give electrically neutral species.[13]The multiblock-copolymer aqueous solution (30 wt.-%) is a low-viscosity sol (g¢~100 Pas) at 37 C at pH 7.4, indicating that the polymer solution can be injected without gelling and blocking a needle. In addition, the adhesive force of the multiblock poloxamer gel at pH 4±6 (about 14±16 Pa) increased by more than ten times from that of the original poloxamer (P85 has an adhesive force of about 1 Pa) by the introduction of the carboxylic acid. The increased adhesion force indicates the stability of the gel at the applied sites. An in-vitro study showed that the gel prepared from a BMP solution (30 wt.-%) persists for two days at pH 4.5 (vaginal pH), which is three times longer than the poloxamer (P85) gel.In conclusion, we are reporting a unique closed-loop sol±gel±sol transition of a multiblock-poloxamer aqueous solution as a function of pH. The counterbalance between the ionization of carboxylic acid groups and the PEG solubility in water seem to be responsible for the phase behavior. The problems of injectability and the small adhesive force of the unmodified poloxamer were significantly improved by our multiblock-copolymer system. ExperimentalThe poloxamer (P85 obtained from BASF, consisting of ethylene glycol (EG) and propylene glycol (PG) blocks in the ratio (EG) 26 -(PG) 40 -(EG) 26 ) was dissolved in toluene, and the solvent was partially removed by distillation in order to remove adsorbed water from the polymer. Terephthalic anhydride (Aldrich) and triethylamine (Aldrich) were added, and the reaction mixtures were stirred at 100 C for 12 h. The product was isolated by precipitation into diethyl ether, and residual solvent was removed under vacuum. The 1 H NMR (CDCl 3 ) spectrum of the multiblock poloxamer shows the ethylene glycol unit (3.6 ppm), propylene glycol unit (1.5 ppm), and aromatic hydrogens (7.2 ppm). Fourier-transform IR (FTIR) spectroscopy shows the ester formation at 1730 cm ±1 by the coupling reaction. For gel permeation chromatography (GPC) analysis, tetrahydrofuran was used as an eluting solvent, and poly(ethylene glycol) standards with molecular weights of 1000 g mol ±1 , 4600 g mol ±1 , 10 000 g mol ±1 , and 30 000 g mol ±1 were used for calibration. Styragel columns (HT3, used in series) were used. The weight-average molecular weight of the multiblock poloxamer was 10 000 g mol ±1 . The sol-to-gel transition of the polymer aqueous solution was investigated using dynamic rheometry (Thermo Haake, Rheometer RS 1) by the method previously de...

The purpose of this study was to develop Situation, Background, Assessment, Recommendations(SBAR) program and to test the effects of the program on communication clarity, clinical competence, and self-efficacy for clinical nurses in cancer hospitals. Methods: This study applied a nonequivalent control group non-synchronized design. There were 28 participants in the intervention group and 27 in the control group. SBAR program consisted of 4 parts and applied for 6 weeks in the intervention group. Data were analyzed with x 2 test, Fisher's exact test, t-test and ANCOVA using the SPSS program. Results: Communication clarity, clinical competence and self efficacy were significantly increased in the intervention group compared to those in the control group. Conclusion: These results suggest that SBAR program may improve communication clarity, clinical competence and self-efficacy for clinical nurses in cancer hospitals. Therefore, it is required to actively take advantage of this program to improve communication clarity among medical staffs, clinical competence, and self-efficacy in clinical nursing practices.