A reactive compatibilization with the compound containing four epoxy groups for polylactic acid/poly(butylene adipate-co-terephthalate)/thermoplastic starch ternary bio-composites.

How to effectively improve the poor interfacial adhesion between polylactic acid/poly(butylene adipate-co-terephthalate) (PLA/PBAT) matrix and thermoplastic starch (TPS) is still a challenge. Therefore, this work aims to introduce a convenient method to enhance the performance of PLA/PBAT/TPS blend by melt reactive extrusion. Here, using 4,4'-methylene-bis(N,N-diglycidyl-aniline) (MBDG) containing four epoxy groups as a reactive compatibilizer, and respectively using 1-methylimidazole (MI) or triethylenediamine (TD) as a catalyzer, serial PLA/PBAT/TPS ternary bio-composites are successfully prepared via melt reactive extrusion. The results showed that, under the catalysis of organic base, especially MI, the epoxy groups of MBDG can effectively react with hydroxyl and carboxyl groups of PLA/PBAT and hydroxyl groups in TPS to form chain-expanded and cross-linked structures. The tensile strength of the composites is increased by 20.0 % from 21.1 MPa, and the elongation at break is increased by 182.4 % from 17.6 % owing to the chain extension and the forming of cross-linked structures. The molecular weight, thermal stability, crystallinity, and surface hydrophobicity of the materials are gradually improved with the increase of MBDG content. The melt fluidity of the composites is also improved due to the enhancement of compatibility. The obtained PLA/PBAT/TPS materials have the potential to be green plastic products with good properties.

[A 10-year-review (1998 - 2007) on 3449 cases of osteoporotic hip fractures: trend of hospitalization and inpatient costs].

OBJECTIVE: The purpose of this retrospective research was to analyze the trend of hospitalized prevalence in the past 10 years (1998 - 2007) and to estimate resource utilization associated with osteoporotic hip fractures, including hospital length of stay and inpatient costs in Guangzhou, China. METHODS: 3449 patients aged 50 years and older, hospitalized for primary diagnose of hip fractures in both hospitals in the past ten years were included in our study. Completed data was obtained retrospectively from the hospital medical records. Clinical parameters such as sex-specifics, hospital length of stay, inpatient costs, and the constitutions of the inpatient costs were analyzed with multiple statistics methods and regressions. RESULTS: Over the 10-year study period, the number of hospitalizations for hip fractures increased with a curve model. Male and female ratio was 1:1.95 with an average age of the patients as 76.32 +/- 9.52 years old. Average hospital length of stay was 23.59 +/- 13.48 days with no significant difference between males and females, years of admission and the different diagnoses. The number of hospitalization went to the top at the age of 70 to 79 years old (38.45%), followed by 80-89 years old (33.08%). Femoral neck fractures was significantly more than that of inter-trochanteric fractures in those patients aged 50 to 79 years (P < 0.01) but less than those intertrochanteric fractures aged 90 years and older (P < 0.05). Average inpatient costs is about 23.52 +/- 17.00 thousand Yuan (RMB) (femoral neck fractures is about 25.09 +/- 17.62 thousand Yuan and intertrochanteric fracture is 21.44 +/- 15.92 thousand Yuan) of which treatment costs (included implants, materials used in the theatre and routinely care of the wound) contributed 52%, pharmacy intervention 25%, operation 6%, ward expenditure 5%, radiology and physical investigation 5%, and chemistry test 4%. The inpatient cost went to a peak at the age of 60 - 69 years old and were significantly correlated with the hospital length of stay. The cost increased every year in the past 10 years by 6.18%. CONCLUSION: These results emphasized that the growing economic impact arising from the inpatient treatment of osteoporotic hip fractures and most of which related to treatment cost (include implants, materials used in the theatre and routinely care of the wound), and drugs and always correlated to length of hospital stay. Cost control should be paid more attention to the implants and drugs.