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Biomedical subjects

J Sokoloff

Publications and source records attributed to J Sokoloff.

16 recordsLinked to original sources

Negative refraction and left-handed electromagnetism in microwave photonic crystals.

We demonstrate the negative refraction of microwaves in a metallic photonic crystal prism. The spectral response of the photonic crystal prism, which manifests both positive and negative refraction, is in complete agreement with band-structure calculations and numerical simulations. The validity of Snell's law with a negative refractive index is confirmed experimentally and theoretically. The negative refraction observed corresponds to left-handed electromagnetism that arises due to the dispersion characteristics of waves in a periodic medium. This mechanism for negative refraction is different from that in metamaterials.

Journal Article↗

Tribal education: reflections from the Pine Ridge Indian reservation.

Attracting and retaining Native American nursing students is crucially important to the health and well-being of Native American populations. Tribal institutions of higher education are doing excellent work, but their continued progress depends on an awareness of their successes, difficulties and functional requirements. This article shares the authors' experiences in teaching nursing Oglala Lakota College's associate degree program on the Pine Ridge Reservation, South Dakota, an area approximately the size of the State of Delaware. The authors wish to alert the larger nursing community to some of the educational and health care needs and issues of this population, to communicate the importance of the work of tribal nursing programs and to illustrate the experience as an opportunity for nurses who are interested in multicultural development.

Cultural Characteristics↗

Limitations of renal function scanning in acute obstruction.

This study was designed to determine if technetium-99m penicillamine (TPEN), could be used to predict recoverable function in dogs with acute obstruction. Renal accumulation of TPEN was measured in four control dogs, in four dogs with acute obstruction lasting 7-14 days, and in the same four dogs following a variable recovery period of 15-63 days. The relative renal uptake of TPEN in vivo showed good agreement with the relative uptake in vitro and both measurements correlated closely with the relative inulin clearances in the normal and in the post obstructed kidneys. The uptake of TPEN in the obstructed kidney following 7-14 days of obstruction averaged 6.8% of the total renal uptake. After relief of the obstruction and a variable recovery period the relative uptake of TPEN in the post obstructed kidney had increased to a mean of 29.5%. These results indicate that TPEN scans should not be used during acute obstruction to predict recoverable function. The observations noted in the study almost certainly apply to similar chelating agents such as dimercaptosuccinic acid (DMSA) and probably to other renal radiopharmaceuticals as well.

Animals↗

Eosinophilic granuloma of lung. Clinical aspects of primary histiocytosis in the adult.

One hundred cases of eosinophilic granuloma diagnosed by open lung biopsy were reviewed. There were 60 women and 40 men, ages 18 to over 60 years. Radiographs and clinical histories were contributed by physicians referring the cases for pathological consultation. Clinical follow-up information was obtained in 60 cases. The outcome was generally benign; the 16 asymptomatic patients remained well; 17 others had complete remission of symptoms, 22 had persistent symptoms, though half had partial improvement; 4 patients had progressive disease despite treatment, but only 1 patient died (of bilateral pneumothoraces complicating severe fibrosis). The more severe manifestations were found in young men, who had a higher incidence of pneumothorax, fibrosis and honeycombing, and diabetes insipidus. Many previously reported cases have had a less favorable outcome; milder cases of primary pulmonary histiocytosis have probably been overlooked in the past. In this series the prognostic value of histologic, clinical, or radiologic findings was limited. The diagnosis can often be strongly suggested radiologically, though infectious granulomata must be excluded; it is arguable whether exclusion of sarcoidosis is clinically important. The effectiveness of treatment with adrenal corticosteroids could not be assessed because of lack of controls; some individuals appeared to benefit, but relapse was very unusual in any case. The etiology of EG remains obscure, but in view of the paucity of patients with a history of allergy or asthma, and the lack of eosinophilia in any case, hypersensitivity seems unlikely. Smoking was far more common among these patients (97% altogether; 80% current) than in the general population (about 35%), an unexplained finding.

Adolescent↗

Spinal subdural hematoma.

The authors report a case of subacute spinal subdural hematoma in a patient with ankylosing spondylitis. Only 18 such cases have been reported in the nonradiological literature. Early diagnosis is imperative in order to minimize neurological sequelae.

Hematoma, Subdural↗

The prone chest film.

Frontal chest radiographs in the prone position enhanced visualization of the posterior lung base in the presence of pleural effusions. Though the lateral decubitus view often displaced fluid adequately, in several cases only the prone film revealed basilar lung pathology; this was due to gravitational shift of the fluid away from this region as well as improved aeration of the lower lobe in the prone position, as shown by horizontal-beam lateral views. The prone chest film is recommended for evaluation of the lung base when obscured by fluid.

Abdominal Muscles↗

Tribal education: reflections from the Pine Ridge Indian Reservation.

Attracting and retaining Native American students in tribal nursing programs is crucial to the health and well-being of Native American populations. The authors share their experiences teaching nursing in the associate degree program at the Oglala Lakota College on the Pine Ride Reservation in South Dakota. The authors communicate the importance of the work of tribal nursing programs and illustrate the experience as an opportunity for nurses who are interested in cross-cultural development.

Cultural Characteristics↗