Compton scattering tomography for agricultural measurements

This paper presents a new approach in tomographic instrumentation for agriculture based on Compton scattering, which allows for the simultaneous measurements of density and moisture of soil samples. Compton tomography is a technique that can be used to obtain a spatial map of electronic density of samples. Quantitative results can be obtained by using a reconstruction algorithm that takes into account the absorption of incident and scattered radiation. Results show a coefficient of linear correlation better than 0.81, when comparison is made between soil density measurements based on this method and direct transmission tomography. For soil water contents, a coefficient of linear correlation better than 0.79 was found when compared with measurements obtained by time domain reflectrometry (TDR). In addition, a set of Compton scatter images are presented to illustrate the efficacy of this imaging technique, which makes possible improved spatial variability analysis of pre-established planes.

Hepatectomia direita por videolaparoscopia

The first application of laparoscopic liver surgery consisted of wedge liver biopsies or resection of peripheral lesions, mostly benign. More recently, reports of anatomic left and right hepatectomy have been seen in the literature. Expertise in some centers has evolved to such an extent that even living related donor hepatectomy has been performed. The aim of this paper is to report a laparoscopic right hepatectomy and describe in detail the surgical technique employed. To our knowledge this is the first case performed in Brazil totally laparoscopically. The surgery followed four distinct phases: complete mobilization of the liver; hilum dissection with encircling of right portal vein and right hepatic artery, caval dissection using linear vascular stapler to divide right hepatic vein and parenchymal transection with harmonic shears and firings of linear staplers are used to divide segmental 5 and 8 branches of middle hepatic vein. The liver specimen was removed by Pfannenstiel incision. Intraoperative blood loss was estimated in 120 ml with no need for blood transfusion. Hospital stay was 5 days. Laparoscopic right hepatectomy is feasible, technically demanding but can be safely accomplished by surgeons who have experience in advanced laparoscopic procedures and open hepatic surgery. In Brazil laparoscopic liver surgery is still in its first years and there is a lack of technical description of this complex procedure.