Design of abdominal retractor.

INTRODUCTION: The purpose of this paper is to present the development and design of an abdominal retractor which allows a single person to perform operations and the fixation of the operation instruments can be done with one hand. The additional devices make the operation more comfortable for surgeons. METHODS: Conventional measuring devices have been designed and applied for determining axial forces in a surgeon's forearm during operations. The same forces must be transmitted by the frame of the retractor. Thus a simple truss structure of a retractor was done. Several types of fixations have been proposed and tested using the rapid prototyping. Finally, the abdominal retractor was manufactured from stainless steel. RESULTS: The simple-to-use abdominal retractor was built. The standard surgery instruments were modified due to the fixation system of the frame. A wide variety of additional useful devices, such as a lamp, video camera etc., were also proposed. CONCLUSION: The present abdominal retractor is user-friendly and all components are easily sterilized by conventional methods (Fig. 7, Ref. 6) Keywords: abdominal retractor, stainless steel retractor, standard surger, fixation system of the frame, lamp, video camera, conventional methods.

In vitro Screening of Essential Oil Active Compounds for Manipulation of Rumen Fermentation and Methane Mitigation.

The objective of this study was to investigate the effects of 11 active compounds of essential oils (ACEO) on rumen fermentation characteristics and methane production. Two trials were conducted. In trial 1, ACEO (eugenol, carvacrol, citral, limonene, 1,4-cineole, p-cymene, linalool, bornyl acetate, α-pinene, and ß-pinene) at a dose of 1,000 µL/L were incubated for 24 h in diluted rumen fluid with a 70:30 forage:concentrate substrate (16.2% crude protein; 36.6% neutral detergent fiber). Three fistulated Holstein cows were used as donors of rumen fluid. The reduction in methane production was observed with nine ACEO (up to 86% reduction) compared with the control (p<0.05). Among these, only limonene, 1,4-cineole, bornyl acetate, and α-pinene did not inhibit volatile fatty acid (VFA) production, and only bornyl acetate produced less methane per mol of VFA compared with the control (p<0.05). In a subsequent trial, the effects on rumen fermentation and methane production of two concentrations (500 and 2,000 µL/L) of bornyl acetate, the most promising ACEO from the first trial, were evaluated using the same in vitro incubation method that was used in the first trial. In trial 2, monensin was used as a positive control. Both doses of bornyl acetate decreased (p<0.05) methane production and did not inhibit VFA production. Positive effects of bornyl acetate on methane and VFA production were more pronounced than the effects of monensin. These results confirm the ability of bornyl acetate to decrease methane production, which may help to improve the efficiency of energy use in the rumen.