ABSTRACT
Polyhydroxyalkanoates (PHAs) are polymers obtained by esterification of hydroxy fatty acid monomers. Due to similar mechanical characteristics of traditional petroleum-based plastics, 100% biodegradability and biocompatibility, PHAs are considered to be one of the most potential green materials. However, the application and promotion of PHAs as a green and environmentally friendly material are difficult because of the high production costs. This article focuses on the current methods to reduce production cost of PHAs effectively, such as cell morphology regulation, metabolic pathway construction, economic carbon source utilization and open fermentation technology development. Despite most research results are still limited in laboratory, the research methods and directions provide theoretical guidance for the industrial production of economic PHAs.
Subject(s)
Fermentation , Industry , Petroleum , Plastics , PolyhydroxyalkanoatesABSTRACT
Objective To evaluate the impact of the re-modified Sugiura procedure on portal hemodynamics and liver function in cirrhotic patients with portal hypertension.Methods Forty patients with cirrhosis and portal hypertension who underwent the re-modified Sugiura procedure in the Yichang Second People's Hospital from June 2006 to October 2014 were studied.Changes in the free portal pressure (FPP),portal venous flow (PVF) and liver functions before and after operation were analyzed.Results (1) The FPP at different phases of the operation (after opening the abdomen,after splenectomy,and after devascularization) were (43.2 ± 1.8) cmH2O,(34.8 ± 1.6) cmH2O and (35.2 ± 1.7) cmH2O,respectively.There were significant differences in FPP between the phases of after splenectomy and after opening the abdomen,as well as after devascularization and after opening the abdomen (P ＜ 0.05).There was no significant difference in FPP between after devascularization and after splenectomy (P ＞ O.05).(2) The PVF,which were measured with Doppler sonography at 4 time points (preoperative 1 day,postoperative 10 days,postoperative 6 months,postoperative 18 months),were (1 420.4 ± 137.7) ml/min,(1 205.2 ± 126.7) ml/min,(875.8 ± 118.0) ml/min and (893.8 ± 114.7) n1/min,respectively.There were significant differences in PVF between postoperative 10 days and preoperative 1 day,between postoperative 6 months and postoperative 10 days,as well as between postoperative 18 months and preoperative 1 day (P ＜0.05).There was no significant difference in PVF between postoperative 18 months and postoperative 6 months (P ＞0.05).(3)The liver functions were evaluated using the Child-Pugh score at 4 time points (preoperative 1 day,postoperative 10 days,postoperative 6 months,postoperative 18 months).There were no significant differences among the time points,(P ＞ 0.05).Conclusion The re-modified Sugiura's procedure durably,appropriately and effectively reduced the PVF and FPP,but it did not have any negative effects on the liver functions of patients with cirrhosis.