ABSTRACT
Iron powders and Fe/graphene oxide and Fe/boron nitride composites were synthesized by means of a polyol synthesis method. The effect of NaOH/Fe and ascorbic acid/Fe ratios on the characteristics of synthesized products were evaluated. The samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, low-temperature nitrogen adsorption and Raman-spectroscopy. Ascorbic acid-assisted polyol synthesis resulted in the 10-fold decrease of the iron particles' size and almost 2-fold increase of lead removal efficiency. The deposition of iron on the surface of graphene oxide lead to the formation of small 20-30 nm sized particles as well as bigger 200-300 nm sized particles, while the reduction in presence of boron nitride resulted in the 100-200 nm sized particles. The difference is attributed to the surface state of graphene oxide and boron nitride. Adsorption properties of the obtained materials were studied in the process of Pb2+ ion removal from wastewater.
ABSTRACT
BACKGROUND: Acid peptic perforation of the duodenum remains a surgical challenge. Plication alone may be satisfactory management if the ulcer diathesis is medically controlled. Laparoscopic management for plication has been safely applied in a variety of populations. This study assessed a combination of endoscopy and laparoscopy to manage early duodenal perforation. STUDY DESIGN: Forty-two patients with early (less than 12 hours) perforation were managed by laparoscopic plication and lavage. Endoscopy identified the site of perforation and guided repair in 35 of 42. All patients were followed with Helicobacter pylori treatment and examined by endoscopy at 3 months. Forty case control patients who had open procedures for duodenal perforation were evaluated for comparison. RESULTS: Endoscopic/laparoscopic management was completely effective and compared favorably with open procedures with regard to surgical time and complications. Endoscopic snaring of omentum and pulling into the defect proved to be an effective adjunct for plication. CONCLUSIONS: Endoscopic/laparoscopic repair of perforated duodenal ulcers is a safe and effective surgical tactic if followed by treatment for Helicobacter pylori.
