Biliary fistula and late recurrence of liver hydatid cyst:Role of cystobiliary communication:A prospective multicenter study

BACKGROUND Hydatid cyst disease(HCD)is common in certain locations.Surgery is associated with postoperative biliary fistula(POBF)and recurrence.The primary aim of this study was to identify whether occult cysto-biliary communication(CBC)can predict recurrent HCD.The secondary aim was to assess the role of cystic fluid bilirubin and alkaline phosphatase(ALP)levels in predicting POBF and recurrent HCD.AIM To identify whether occult CBC can predict recurrent HCD.The secondary aim was to assess the role of cystic fluid bilirubin and ALP levels in predicting POBF and recurrent HCD.METHODS From September 2010 to September 2016,a prospective multicenter study was undertaken involving 244 patients with solitary primary superficial stage cystic echinococcosis 2 and cystic echinococcosis 3b HCD who underwent laparoscopic partial cystectomy with omentoplasty.Univariable logistic regression analysis assessed independent factors determining biliary complications and recurrence.RESULTS There was a highly statistically significant association(P≤0.001)between cystic fluid biochemical indices and the development of biliary complications(of 16 patients with POBF,15 patients had high cyst fluid bilirubin and ALP levels),where patients with high bilirubin-ALP levels were 3405 times more likely to have biliary complications.There was a highly statistically significant association(P≤0.001)between biliary complications,biochemical indices,and the occurrence of recurrent HCD(of 30 patients with recurrent HCD,15 patients had high cyst fluid bilirubin and ALP;all 16 patients who had POBF later developed recurrent HCD),where patients who developed biliary complications and high bilirubin-ALP were 244.6 and 214 times more likely to have recurrent hydatid cysts,respectively.CONCLUSION Occult CBC can predict recurrent HCD.Elevated cyst fluid bilirubin and ALP levels predicted POBF and recurrent HCD.

Optimizing a spark-ignition engine fuelled with methane using a two-zone combustion model

Methane which can be produced from biogas has a great potential to be used as an alternative renewable fuel for spark-ignition engines.However,engines need to be optimized for methane use.The aim of this study was to numerically optimize a spark-ignition engine fueled with methane and operated at a constant speed of 1,500 rpm via using a validated two-zone combustion model.The model was able to predict engine performance parameters,NO emission,and engine knock at different engine operating conditions including inlet pressure,compression ratio,and excess air factor.Engine knock was prevented by increasing the excess air factor up to 1.2 when the engine operated with higher inlet pressure and compression ratio.It was found that a maximum inlet pressure of only 120 kPa could be used with an engine compression ratio of 14 and excess air factor of 1.2 for knock free operation.The peak engine power was produced when the engine operated with an inlet pressure of 200 kPa and compression ratio of 8 or 9.It was also found that the optimum operating condition which resulted in high engine power accompanied with low fuel consumption and high efficiency was obtained when the engine operated with an inlet pressure of 180 kPa and a compression ratio of 11.This condition required the engine to operate with an excess air factor of 1.19 to prevent engine knock.However,operating the engine at this optimum condition would be accompanied with high NO emission.

Biomaterials for Adhesion in Orthopedic Applications:A Review

Adhesive biomaterials,historically,have had a wide range of applications in all medical fields.With the extensive variety of biomaterials with adhesion properties,the field of orthopedics benefits from using adhesives which can provide superior biocompatibility,resorbability,and low immunogenicity.The goal of this review is to serve as a reference of the types of adhesive biomaterials used clinically and their specific applicability in the field of orthopedics.The applications of adhesive biomaterials in orthopedics are as scaffolds,filler materials to treat bone defects and as carrier materials to deposit other bioactive materials to a site.First,we review the history and background of adhesive biomaterials and some of their general applications in orthopedics.Then we focus on the various types of adhesive biomaterials which include fibrin,collagen,polyurethane,epoxy resin,cyanoacrylates,polyesters and polymethylmethacrylate,all of which are excellent candidates for the field of orthopedics.We discuss their properties,current applications in all fields,and advantages and disadvantages found in some studies.Lastly,we indicate some future directions for adhesive biomaterials in orthopedics and highlight their advantages over conventional biomaterials in orthopedics.