Custom-made Instrument Research Articles

Assessment of the strength of minicapsulorhexes

To evaluate the effect of age, size, position, and species on the strength of minicapsulorhexes. Surgical Suite and Laser Laboratory, Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA. Capsulorhexes 0.7 to 2.3 mm in diameter were made centrally or peripherally in 35 eye-bank eyes and 32 rabbit eyes. A custom-made instrument stretched the capsulorhexes until rupture. Load and stretch at rupture were recorded. Maximum load and stretch were 26.3 mN +/- 20.3 (SD) and 50% +/- 18% for central and 50.8 +/- 20.5 mN and 69% +/- 17% for peripheral capsulorhexes in eye-bank eyes and 19.8 +/- 15.2 mN and 38% +/- 13% for central and 13.5 +/- 9.5 mN and 30% +/- 7% for peripheral capsulorhexes in rabbit eyes. Peripheral capsulorhexes were stronger and more elastic than central capsulorhexes in eye-bank eyes, and maximum load and stretch increased statistically with the capsulorhexis diameter. Peripheral minicapsulorhexes were more resistant to rupture than central capsulorhexes in eye-bank eyes, probably because of increased lens capsule thickness at the periphery. An increase in capsulorhexis diameter increased the resistance to rupture.

On-column labeling reaction for analysis of protein contents of a single cell using capillary electrophoresis with laser-induced fluorescence detection.

This chapter presents methods for capillary electrophoresis (CE) fingerprinting of proteins in a cell extract and in single cells. A custom-made CE instrument with laser-induced fluorescence (LIF) detection, used for the analyses, is described. Detailed procedures are given for: (1) on column labeling of proteins with a fluorogenic reagent, 5-furoyl quinoline-3-carboxaldehyde, (2) CE separation of labeled proteins, (3) preparation of a protein extract from cultured cells, and (4) manipulations associated with analyses of proteins in single cells. More than 20 relevant publications are cited in this chapter to assist the reader with adopting the presented methods.

Assessing Competency in Business Writing

Assessing the level of improvement of students' writing competency during a semester is becoming increasingly important for business communication instructors. When conducting an assessment, instructors need to be aware of issues that will affect reliability and validity. They need to develop cleargoals at the beginning; for example, good assessment strives to improve instruction and to develop students' communication skills. Because different schools have different missions and operate in different environments, a custom-made instrument will ensure that the assessment fits the local conditions. Before con ducting the assessment, the instrument needs to be validated for specific use, and scorers must be trained in holistic scoring to reach an overall assessment.

Aseptic laparoscopic colon resection with intraabdominal anastomosis. An experimental study in pigs.

We evaluated a new aseptic method for laparoscopic left colon resection in terms of technical feasibility and outcome. Ten pigs were operated on under general anesthesia. Pre- and postoperative body weight, stools, behavior, and need for analgesics were recorded. Fourteen days later, the animals were killed. At autopsy, the degree of intraabdominal adhesions was noted. The anastomoses were sent for histological examination. The entire procedure was performed intracorporeally, and no antibiotics were given. After division of the mesocolon, the segment to be resected was invaginated down through the colon. This was facilitated by a custom-made instrument that was introduced into the bowel via the anus; it consisted of a pull-out device and a modified diathermy wire. The anastomosis was completed at the invagination fold by a row of hernia staples that were covered by an interrupted suture. Then the invaginated bowel was transected by the diathermy wire and delivered through the anus. One animal was killed before completion of the operation because of a colonic perforation. The remaining nine animals had an uneventful and rapid recovery. They ate from the 1st postoperative day and gained weight rapidly. Stools were normal after 2 days (median), and normal behaviour was noted in all animals from the 1st postoperative day. At the postmortem examination, intraabdominal adhesions were observed in two animals. In one case, the adhesions extended from a hematoma in the mesentery to the abdominal wall. There were no adhesions to the anastomosis or the colon. In the other case, the anastomosis adhered to the right uterine tube and a loop of small intestines. The method is technically feasible, but a modification is suggested for cases where the invagination is impossible. Recovery after the operation is rapid.

Mechanical properties of coated copper mirrors

Copper mirrors are generally used in optical systems for handling CO 2 laser beams. The presence of a protective coating on the mirror surface is necessary to increase the lifetime of mirrors working in a hostile environment. The mechanical properties (adhesion, hardness and abrasion) of Y 2O 3 and a-C:H protective thin films on copper mirrors have been investigated. Y 2O 3 and a-C:H coatings have been deposited by rf sputtering and dual ion beam sputtering, respectively. The coating adhesion has been measured by the ‘scratch test’ and the ‘topple test’, while the hardness has been measured with the knoop microindentation technique. In order to estimate the abrasion resistance of the samples, the ‘eraser test’ has been performed with a custom-made instrument.

'Figure 8' ipsilateral autokeratoplasty. A modification using standard corneal trephines.

A modification of the "figure 8" ipsilateral autokeratoplasty uses a silicone wafer beneath a portion of a standard sized corneal trephine to limit its cutting edge. This procedure eliminates the necessity of a custom-made instrument in a seldom-performed operation.