Representing the special linear group with block unitriangular matrices.

We prove that every element of the special linear group can be represented as the product of at most six block unitriangular matrices, and that there exist matrices for which six products are necessary, independent of indexing. We present an analogous result for the general linear group. These results serve as general statements regarding the representational power of alternating linear updates.

How to analyze an article.

In clinical research investigators generalize from study samples to populations, and in evidence-based medicine practitioners apply population-level evidence to individual patients. The validity of these processes is assessed through critical appraisal of published articles. Critical appraisal is therefore a core component of evidence-based medicine (EBM).

Mortality secondary to esophageal anastomotic leak.

Background: Esophageal anastomotic leak is a potentially life threatening complication of esophagectomy and esophagogastrectomy. We reviewed our experience with this complication and tried to identify factors predictive of mortality after esophageal anastomotic leak.

Methods: Records of patients undergoing esophagectomy and esophagogastrectomy for benign or malignant disease over a 10-year period (1989-1999), who developed esophageal anastomotic leaks, were reviewed.

Effect of fibrin glue on air leak and length of hospital stay after pulmonary lobectomy.

Aim: Air leaks are a common cause of morbidity and prolonged hospital stay after pulmonary lobectomy. We reviewed our experience with intraoperative fibrin glue to determine if it reduced air leak and improved patient outcomes.

Methods: Records of patients undergoing pulmonary lobectomy for benign or malignant disease over a 4-year period (1998-2001) were reviewed.

Preoperative and intraoperative factors predictive of length of hospital stay after pulmonary lobectomy.

Background: Length of hospital stay is an important determinant of overall surgical costs. Health care resources are finite, so reductions in length of stay are desirable. We reviewed our experience with pulmonary lobectomy to identify preoperative and intraoperative factors that predicted the length of postoperative hospital stay.