36 research outputs found
Association of Prolonged QRS Duration With Death in a Clinical Trial of Pacemaker Therapy for Sinus Node Dysfunction
Outcome of cardiopulmonary resuscitation after in-hospital cardiac arrest in octogenarians
Laser Chemotherapy of Human Carcinoma Cells with Three New Anticancer Drugs
A new experimental therapy for squamous carcinoma was tested by sensitizing human tumor cells with light-sensitive anticancer drugs followed by laser illumination at visible or infrared wavelengths. The anthrapyrazole DUP-941 and the isoquinoline derivative DUP-840 were compared with the dianthraquinone hypericin. P3 human squamous carcinoma cells were incubated for 2 h with the drugs at escalating doses ranging from 5 to 100 micrograms/ml, then exposed to visible green 532-nm or infrared 1064-nm light at 300 J output from a KTP/Nd:YAG laser. Tumor cell toxicity measured by in vitro MTT viability assays was minimal after DUP-840 uptake but was slightly enhanced by infrared laser emissions. By contrast, the strong tumoricidal effects seen after DUP-941 uptake were amplified over 10-fold by 532-nm light and up to 2-fold by 1064-nm light. Hypericin-sensitized tumor cells were killed after 532 nm irradiation even at the lowest drug dose but were not affected by 1064-nm illumination. The results suggest that laser chemotherapy with drugs sensitive to photothermal energy could become a useful new treatment modality for cancer
Effects of dietary forage level and monensin on lactation performance, digestibility and fecal excretion of nutrients, and efficiency of feed nitrogen utilization of Holstein dairy cows
Double blind controlled study of low dose intravenous perindoprilat or enalaprilat infusion in elderly patients with heart failure.
Comportamento adjunto: controvérsias e contribuições teóricas
A área de investigação sobre comportamento adjunto, cujas pesquisas tiveram início na década de 60, é extensa e controvertida. O presente trabalho analisa as interpretações mais importantes do fenômeno, e mostra que diversas características apresentadas como próprias do comportamento adjunto também estão presentes em outros comportamentos. Falk interpretou o comportamento adjunto como atividade deslocada, Staddon como comportamento induzido por esquema, Timberlake como parte de um sistema comportamental pré-programado, e Wetherington questionou a existência de uma terceira classe de comportamento. Conclui-se que as tentativas de sistematização têm se mostrado incompletas devido à diversidade de topografias de comportamentos adjuntos e a sua dependência de variáveis tanto do esquema como da espécie e do ambiente