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991.
Gisela Ruhland 《Development genes and evolution》1955,147(4-5):365-372
Ohne Zusammenfassung 相似文献
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996.
Gisela P. Concepcion 《Bioscience Hypotheses》2009,2(1):24-26
Prions are multi-stable proteins that can assume at least two stable conformations: a normal one that is detergent-soluble and is protease-sensitive, and a pathogenic one that is protease-resistant and that forms detergent-insoluble fibrillar aggregates. The fibrillar aggregates have been implicated in various neurodegenerative disorders. The normal biological function of prions is not known, yet the high conservation of the sequences of prions among distantly related animals strongly suggests a common and important function. There is now increasing evidence that prions, which are abundant in nervous tissue, may in fact be involved in memory retention. We propose that electrical activity at the synapse induces the surrounding prion molecules to aggregate. The aggregates serve to hold together the synaptic connection between neurons which are interacting at the instant the sensory stimulus is received. The set of neurons connected in this manner then form the neuronal circuit which is associated with the particular stimulus. We propose that the stronger the electrical activity, the greater will be the aggregations. Long-lasting memory will result from traumatic, or exciting, experiences. Further, the aggregations will be maintained, or reinforced, by repeated stimulation of the same set of neurons. Memory loss will occur when those aggregates dissolve. 相似文献
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Background
All polypeptide backbones have the potential to form amyloid fibrils, which are associated with a number of degenerative disorders. However, the likelihood that amyloidosis would actually occur under physiological conditions depends largely on the amino acid composition of a protein. We explore using a naive Bayesian classifier and a weighted decision tree for predicting the amyloidogenicity of immunoglobulin sequences. 相似文献998.
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In good manufacturing practice (GMP) facilities in the biopharmaceutical industry, chromatography resins are largely underutilized during purification of single drug products during clinical production. Chromatography resins are dedicated to a specific product and disposed of, after only a fraction of their lifetime due to concerns of potential product carryover from one program to another. In this study, we follow a resin lifetime methodology typically used for commercial submissions and apply it to determine the feasibility of purifying different products on a Protein A MabSelect PrismA™ resin. Three distinct monoclonal antibodies were used as model molecules. Column performance was monitored through chromatogram profiles, yield, clearance capability of selected media components, pressure and product quality. A protein carryover study was designed to demonstrate that the column cleaning procedures reduced protein carryover to safe cleanliness levels regardless of multiple product contact cycles and the order in which the mAbs are captured. Data show that up to 90 total cycles (30 cycles per antibody), there was negligible protein carryover and impact on process performance. Product quality was consistent, with the only meaningful trends found for the leached Protein A ligand, without affecting the conclusion of the study. While the study was restricted to three antibodies, the proof of concept for resin reuse was demonstrated. 相似文献
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Teresa M. Fonovich Cristina S. Pérez Coll Lucila Blanco Bermudez Mónica Guraya Gisela Cappari Soledad Perez Catán 《Soil & Sediment Contamination》2021,30(2):187-200
ABSTRACT Nanomaterials (Nms) applications and environmental deposition are continuously increasing. Aluminum (Al) and nickel (Ni) fate in soil, both from gamma alumina-based Nms and as chloride salts were evaluted through lysimeters. After 85 days of treatment, which included irrigation and collection of eluates, the soil of each lysimeter was divided into four sections. The metal concentration was analyzed in eluates, soil samples, and extracts. Al and iron (Fe) present in soil eluted from Control lysimeter. Al from Nms suspension treatment was quantified in the eluates since 30 days on. Ni eluted upon solid salt deposition on top of one device. These results indicate that Al and Ni applied under certain conditions on soil, could leach and reach groundwater. The total concentration and bioavailability (extractable metals) of Al and Fe in soils showed similar patterns. Ni was retained only in the soil of devices treated with chloride salts. Bioavailability % results were of concern for Ni under certain conditions of treatment: 15.57% and 11.08% in two chloride salt-treated lysimeters versus 0.55% and 0.47% of those in control and treated with Nms lysimeters. Conducting studies with different kinds of soil and longer treatment periods should be useful to understand Nms-metals fate in the environment. The results presented here constitute important evidences both for significant metal release from Nms and elution and for considerable Ni bioavailability, after deposition on soil in the form of Nms or as a chloride salt, respectively. Then, possible toxic effects could occur through exposure of aquatic and terrestrial organisms. 相似文献