Phyllodes tumor of borderline malignancy: a 7-year follow-up.
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Biomedical subjects
Publications and source records attributed to Y Ren.
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Neurophysiological changes of hippocampal neurons were compared before and after transient forebrain ischemia using intracellular recording and staining techniques in vivo. Ischemic depolarization (ID) was used as an indication of severe ischemia. Under halothane anesthesia, approximately 13 min of ID consistently produced severe neuronal damage in the CA1 region of rat hippocampus, while CA3 pyramidal neurons and dentate granule cells remained intact. After such severe ischemia, approximately 60% of the CA1 neurons exhibited a synaptic potentiation. The excitability of these neurons progressively decreased following reperfusion. Approximately 30% of the CA1 neurons showed a synaptic depression following ischemia. The excitability of these neurons transiently decreased following reperfusion. After ischemia of the same severity, both synaptic transmission and excitability of CA3 and granule cells transiently depressed. These data suggest that ischemia-induced synaptic potentiation may be associated with the pathogenesis of neuronal damage following ischemia, and that the synaptic depression may have protective effects on hippocampal neurons after ischemic insult.
Concerns about consumer and worker safety and the fate of fumigants have fuelled strong efforts to determine their residues in foodstuffs. Fumigants are usually extracted from commodities with solvent at room temperature (25 degrees C). In this paper, solvent extraction of methyl bromide, phosphine, carbonyl sulfide, and carbon disulfide using ultrasonic acceleration or heating was evaluated. Wheat samples plus solvent, in gas-tight bottles, were placed in an ultrasonic chamber or an oven (50 degrees C), and fumigants were released into the headspace over the solvent. Completeness of extraction was demonstrated within 2 h for ultrasonic extraction, 7-20 h for 50 degrees C heating, and 8-35 h for room temperature extraction. The rapidity of extraction was mainly due to ultrasonic vibration rather than increased temperature.