Search

Nanoindentation (NI) is a contact method to investigate localized micromechanical properties of materials, whereby NI of semi-crystalline polymers is challenging. The influence of morphological str...

The importance of polymeric transportation systems has been steadily increasing over the years. It is a useful material in numerous applications, such as packaging, oil and gas pipes, and household items. One particular aspect of polyethylene (PE) is the permeability of small molecules, such as low-molecular-weight hydrocarbons. In the present study, PE sheets were crosslinked by grafting and subsequent hydrolysis of organosilanes during a reactive extrusion process. The formation of a network structure was characterized by sol/gel analysis and by rheological measurements. It is shown that as a result of crosslinking the permeation of linear alkanes through the PE is reduced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45374.

Laparoscopic pyeloplasty offers similar success rates compared to open surgery. However, the advanced laparoscopic skills required may limit its widespread application. In select patients the dorsal lumbotomy approach can provide similar postoperative advantages to minimally invasive surgery. We analyze the perioperative management of laparoscopy vs dorsal lumbotomy for the repair of ureteropelvic junction obstruction.In a retrospective review 13 patients who underwent dorsal lumbotomy pyeloplasty were compared to 19 patients who underwent laparoscopic pyeloplasty between 1998 and 2003. Preoperative confirmation of obstruction was obtained through excretory urogram or renal Lasix scan. All 13 patients undergoing dorsal lumbotomy had a dismembered pyeloplasty. Of the 19 laparoscopic cases 16 had a dismembered pyeloplasty and 3 had a Fenger procedure. Average followup was 12 months for the open group and 13.3 months for the laparoscopic group. Postoperative results were evaluated with excretory urogram or renal Lasix scan as well as subjective outcomes by the patients.Operative time was slightly longer for the laparoscopy group at 231 minutes vs 200 minutes. Estimated blood loss and postoperative morphine requirements were also similar. Hospital stay was 3.3 days for the dorsal lumbotomy group compared to 2.4 for the laparoscopy group. The overall success rate for the laparoscopic group was 94.7% compared to 100% for the dorsal lumbotomy group. Each group had 1 complication, paresthesia of anterior/medial thigh that resolved by 6 months.Our preliminary results show that a dismembered dorsal lumbotomy pyeloplasty is comparable to laparoscopic dismembered pyeloplasty with regard to intraoperative and postoperative hospital course.