Electron injection from colloidal PbS quantum dots into titanium dioxide nanoparticles.

Injection of photoexcited electrons from colloidal PbS quantum dots into TiO(2) nanoparticles is investigated. The electron affinity and ionization potential of PbS quantum dots, inferred from cyclic voltammetry measurements, show strong size dependence due to quantum confinement. On the basis of the measured energy levels, photoexcited electrons should transfer efficiently from the quantum dots into TiO(2) only for quantum-dot diameter below approximately 4.

Missile embolism to the pulmonary artery: case report and pitfalls of management.

Missile embolism to the pulmonary artery is a rare event. We present a complicated case of missile embolism from the inferior vena cava to the pulmonary artery. The case illustrates the potential pitfalls in the management of these patients.

Splenic infarction caused by a large thoracic aortic thrombus.

We report on a patient with left upper quadrant pain as a result of splenic infarction; the patient was subsequently found to have a thoracoabdominal aortic thrombus extending through the celiac axis. The patient was successfully treated with an aortic thrombectomy guided by intraoperative transesophageal echocardiography.

Free-tissue transfers for limb salvage utilizing in situ saphenous vein bypass conduit as the inflow.

Using vein grafts to bypass sclerotic and occluded arterial segments is a well-established technique in vascular surgery. For infrapopliteal bypass, autogenous veins have better patency rates than synthetic grafts. Although not resolved, in situ bypasses seem to be better than reversed bypasses, especially for "far away" segments.

Accessory nerve injury during carotid endarterectomy.

Injury to the accessory nerve (cranial nerve XI) during carotid endarterectomy is rare; to date only three cases have been reported in the literature. Traction on the sternocleido-mastoid muscle was the proposed mechanism of injury in all three cases. Four cases of accessory nerve palsy occurred in 850 carotid endarterectomies performed between 1978 and 1986 at this institution, an incidence of 0.

The collateral hemispheric systolic pressure.

Satisfactory calibrated BP tracings were obtained during 385 (85%) of 455 carotid endarterectomies. The pressures were measured from the distal common carotid arteries while the external carotid arteries were clamp occluded. Continuous recordings were made with and without proximal common carotid clamp occlusion.

Ankle pressure changes in distal bypass grafts during knee flexion.

Systolic ankle blood pressure was measured with the limb extended and then acutely flexed in four study groups. These included 11 normal individuals, 11 patients with below-knee autologous saphenous vein bypass grafts, 11 patients with polytetrafluoroethylene (PTFE) prosthetic below-knee bypass grafts, and 11 patients with femoropopliteal arterial occclusion who had not undergone bypass grafting. This study shows that normal limbs, limbs with saphenous vein bypass grafts, arteriosclerotic limbs, and those with PTFE bypass grafts all tolerate acute knee flexion without significant decrease in distal blood pressure.

Technique for thrombectomy of reversed saphenous vein arterial bypass grafts.

A technique for thrombectomy of saphenous vein arterial bypass grafts is described. The technique includes visual inspection of both anastomoses and avoids unnecessary trauma to the graft secondary to repeated attempts at passing a balloon catheter against the direction of the venous valves.

Summary of cases of adventitial cystic disease of the popliteal artery.

Adventitial cystic disease of the popliteal artery is explored. The results of correspondence with authors reporting this condition are elaborated upon. This has provided an opportunity to discuss the history of the condition, the findings in 115 cases which have come to the attention of the Correspondence Office dealing with this entity, and the results of treatment.

Operative hemorrhoidectomy versus cryodestruction.

Twenty-six patients were treated for hemorrhoids by a combination of cryodestruction and closed operative hemorrhoidectomy. Patients were able to draw their own conclusions about the efficacies of these treatments. They had no difficulty in distinguishing exactly which area was causing pain.

Carotid endarterectomy: a follow-up study of the contralateral non-operated carotid artery.

In a study of 103 patients surviving carotid endarterectomy, follow-up information was obtained from all patients over a period of time extending to four years. This was done so that better decisions could be made regarding recommendations for contralateral carotid surgery. In this follow-up study, only three patients had contralateral surgery.

Rational approach to the differentiation of vascular and neurogenic claudication.

Lower extremity pain caused by exercise but relieved by rest is usually a reliable symptom of chronic arterial insufficiency. However, similar discomfort often occurs in patients with neurospinal compression. Furthermore, arterial occlusive disease and demonstrable spinal stenosis may be present simultaneously.

Hemodynamic and angiographic guidelines in selection of patients for femorofemoral bypass.

Although crossover femorofemoral grafts have had good long-term patency, all patients have not been symptomatically improved. Seventy-one patients underwent 80 femorofemoral bypasses from 1968 to 1978. Hemodynamic assessment included preoperative and postoperative segmental Doppler pressures and femoral artery waveform recordings.

Vascular-laboratory diagnosis of clinically suspected acute deep-vein thrombosis.

Doppler ultrasound, impedance plethysmography, and contrast venography were performed in 207 lower limbs suspected of harbouring deep-venous thrombosis, to clarify the diagnostic value and limitations of the non-invasive methods. Doppler ultrasound and impedance plethysmography were accurate in 96% and 95% of normal limbs, respectively. In limbs with venographic evidence of thrombosis requiring treatment, Dopper ultrasound and impedance plethysmography correctly detected thrombosis in 60% and 97%, respectively.

The asymptomatic carotid bruit and the ocular pneumoplethysmography.

Patients with asymptomatic carotid bruits require some noninvasive method for detecting which would benefit from angiography and possible prophylactic operative repair of the suspected atherosclerotic lesion. This report describes the use of the ocular pneumoplethysmograph (OPG) in this regard. Data for establishing OPG criteria of significant carotid stenosis were derived from studies in symptomatic patients who had also undergone angiography.

Efficacy of preoperative and postoperative bone scanning in the management of breast carcinoma.

With use of 99mtechnetium-labeled phosphates, we performed preoperative bone scans on 122 women with biopsy-proved breast carcinoma. Only two of the 110 patients with Stage I or II disease had scan abnormalities interpreted as bone metastases. Of 55 patients with normal preoperative scans, 20 later had changes suggesting bone metastases on the subsequent scans, most within 24 months of operation.