Fourier synthesis techniques for NMR spectroscopy in inhomogeneous fields.

This paper describes a method for synthesizing spin rotations with arbitrary space dependence on a sample of noninteracting spin 12 by using nonselective radio frequency pulses and pulsed field gradients. This method is used to map out spatial distribution of inhomogeneous B(0) field and to engineer a space dependent evolution of spins that cancels the space dependent phase spins acquire when precessing in an inhomogeneous magnetic field. The technique allows one to record high resolution spectra in inhomogeneous magnetic field by using only time varying linear gradients and rf fields and is expected to find applications in ex situ NMR.

Elective cesarean hysterectomy: a 5 year comparison with cesarean section.

Elective cesarean sections performed on the obstetric service at the University of Arkansas Medical Center were reviewed for the period January 1, 1970, through December 31, 1974. The purpose of the review was to compare operative and postoperative complications of cesarean section, cesarean section and tubal ligation, and cesarean section and elective hysterectomy. A total of 1,255 cesarean sections were performed of which 207 (17 per cent) were associated with tubal ligation and 242 (18 per cent) with hysterectomy. Elective cesarean hysterectomies were performed for elective sterilization (68 per cent), for medically indicated sterilizations (11 per cent), or for definitive treatment of uterine pathology(21 per cent). All cesarean sections were obstetrically indicated with the exception of 34 primary cesarean hysterectomies performed as definitive treatment of carcinoma in situ of the cervix. The operative procedures were compared in regard to the following characteristics or complications: operating time; incidence of blood transfusions, urinary tract injuries, postoperative bleeding, febrile morbidity, and other postoperative complications; and postoperative hospital days.