Silica hydride intermediate for octadecylsilica and phenyl bonded phase preparation via heterogeneous hydrosilation in supercritical carbon dioxide.

Investigations into the preparation of silica hydride intermediate in supercritical carbon dioxide (sc-CO(2)) that avoids the use of organic solvents such as toluene or dioxane are described. The effects of reaction temperature, pressure and time on the surface coverage of the supercritical fluid generated silica hydride intermediate were studied. Under optimised supercritical conditions of 120°C, 483 bar and 3 h reaction time, silica hydride (Si-H) conversion efficiencies of ca. 40% were achieved for the hydride intermediate prepared from a monofunctional silane reagent (dimethylmethoxysilane). Si-H conversion efficiencies (as determined from (29)Si CP-MAS NMR spectral analysis) for the hydride intermediate prepared from triethoxysilane (TES) in sc-CO(2) were found to be comparable to those obtained using a TES silanisation approach in an organic solvent. (13)C and (29)Si CP-MAS-NMR spectroscopy was employed to provide a complete structural assignment of the silica hydride intermediates. Furthermore, supercritical CO(2) was subsequently employed as a reaction medium for the heterogenous hydrosilation of silica hydride with octadecene and with styrene, in the presence of a free radical initiator. These supercritical fluid generated reversed-phase materials were prepared in a substantially reduced reaction time (3 h) compared to organic solvent based methods (100 h reaction time). Silica functionalisation in sc-CO(2) presents an efficient and clean alternative to organic solvent based methods for the preparation of important silica hydride intermediate and silica bonded stationary phases via a hydrosilation approach.

Intraoperative transesophageal echocardiography.

Intraoperative echocardiography in patients undergoing cardiac surgery was first described in 1972. Interest in intraoperative echocardiography has grown in recent years due to the extensive information provided by 2-dimensional (2-D) and color-flow Doppler imaging via the transesophageal approach. The value of this technique also has been verified in large clinical studies involving patients undergoing cardiac surgery. Intraoperative transesophageal echocardiography (TEE) is very useful in preoperative formulation of surgical plans and in immediate post-operative assessment of surgical results in patients undergoing valve surgery.

Less than lobar resections for bronchogenic carcinoma.

We performed less than lobar resections for peripheral clinical Stage I primary lung cancers on 170 patients treated between 1973 and 1987 at two university centers, one in Hawaii and one in Israel. Most patients were poor risks and several had FEV1 < 1 liter. There were 6 (3.5%) hospital deaths. There were 58 segmental resections, 97 wedge resections and 15 less than lobar resections not otherwise specified. Seventy-three patients (43%) are living free of cancer from 5 to 11 years postoperatively and 20 additional patients died of causes unrelated to lung cancer after 5 years; thus disease free five year survival was 54.7%. Patients with adenocarcinoma had poorer prognosis than other cell types. Twenty-three patients (13.5%) had synchronous or metachronous second primary lung cancers. Nine of these patients are long term survivors. Twenty-four patients (14.1%) developed local recurrences with or without distant metastases. This promising long term cancer-free survival and the frequency of second primary lung cancers justifies less than lobar resection for peripheral, Stage I bronchogenic carcinoma, especially in the poor risk patient.

Automatic implantable cardioverter defibrillator: report of the first two implants in Hawaii.

Sudden cardiac death is the major cause of death in the United States today, claiming over 400,000 victims each year, or one per minute. In the majority of cases, the underlying mechanism is malignant ventricular tachyarrhythmia, with the common substrate being abnormal myocardium from ischemic heart disease or congestive cardiomyopathy.