BACKGROUND: Polyvinyl alcohol (PVA) has similar water content as human tissues, good biocompatibility and high mechanical strength, thereby being utilized as tissue-engineered matrix material. However, the modification in cellular affinity benefits the function as tissue regeneration scaffold materials. OBJECTIVE: To prepare chitosan (CS) / PVA composite scaffold and explore the feasibility of serving as a scaffold for tissue engineering. METHODS: Scaffolds of CS/PVA was fabricated by blending PVA-124 with various amounts of CS using film forming, particle forming, and free-drying methods. Water content, light transmittance, and swelling ratio were tested. Scanning electron microscope was used to observe the configuration of the cress section. RESULTS AND CONCLUSION: A total of 7 different proportional scaffolds were obtained with different PVA and CS dosage. The composite film showed light transmittance between 70%-80%, high water content between 121.2%-162.5% and swelling ratio between 60.3%-133.7%.Composita particle and sponge obtained water content between 82.0%-461.2% and 280.8%-1 939.0%. Composite scaffold with the amount ratio of PVA 0.75 g/CS 0.15 g exhibited the best performance. Scanning electron microscope showed that at a mass ratio of PVA 0.75 g/CS 0.15 g, the scaffold prepared by freeze-drying method had regular, tluffy inner structure, with good mechanics and high water content.

BACKGROUND:Polyvinyl alcohol(PVA)has similar water content as human tissues,good biocompatibility and high mechanical strength,thereby being utilized as tissue-engineered matrix material.However,the modification in cellular affinity benefits the function as tissue regeneration scaffold materials.OBJECTIVE:To prepare chitosan(CS)/PVA composite scaffold and explore the feasibility of serving as a scaffold for tissue engineering.METHODS:Scaffolds of CS/PVA was fabricated by blending PVA-124 with various amounts of CS using film forming,particle forming,and free-drying methods.Water content,light transmittance,and swelling ratio were tested.Scanning electron microscope was used to observe the configuration of the cross section.RESULTS AND CONCLUSION:A total of 7 different proportional scaffolds were obtained with different PVA and CS dosage.The composite film showed light transmittance between 70%-80%,high water content between 121.2%-162.5% and swelling ratio between 60.3%-133.7%.Composite particle and sponge obtained water content between 82.0%-461.2% and 280.8%-1 939.0%.Composite scaffold with the amount ratio of PVA 0.75 g/CS 0.15 g exhibited the best performance.Scanning electron microscope showed that at a mass ratio of PVA 0.75 g/CS 0.15 g,the scaffold prepared by freeze-drying method had regular,fluffy inner structure,with good mechanics and high water content.

OBJECTIVE: Ambulance personnel who witness trauma experienced by patients have been reported to experience positive changes, known as vicarious posttraumatic growth (VPTG). We examined VPTG and its relationship with social support and resilience among ambulance personnel. METHODS: The sample (n=227) was recruited from six emergency centers in China. The measures included the Posttraumatic Growth Inventory (PTGI), the Social Support Rating Scale (SSRS), and the 10-item Connor-Davidson Resilience Scale (CD-RISC-10). Structure Equation Modeling (SEM) and the bootstrapping procedure were used to examine indirect effects. RESULTS: The participants' mean score for VPTG was 68.96 (SD=15.51). Social support had significant direct effects on resilience (β=0.51, p < 0.001) and VPTG (β=0.25, p=0.001), and resilience (β=0.58, p < 0.001) had a significant direct effect on VPTG. Furthermore, social support had a significant indirect effect (0.51×0.58=0.30, p < 0.001) on VPTG through resilience. CONCLUSION: Although the nature of the work of ambulance personnel is not expected to change, the negative effects of the trauma they encounter can be reduced by providing them with more support resources and interventions to foster their resilience, which in turn, promote VPTG.
Ambulances* ; China* ; Emergencies ; Humans