Lifelong graph learning deals with the problem of continually adapting graph neural network (GNN) models to changes in evolving graphs. We address two critical challenges of lifelong graph learning in this work: dealing with new classes and tackling imbalanced class distributions. The combination of these two challenges is particularly relevant since newly emerging classes typically resemble only a tiny fraction of the data, adding to the already skewed class distribution.
View Article and Find Full Text PDFConditions to obtain two polymorphic forms by crystallization from solution were determined for the analgesic drug hydro-morphone [C17H19NO3; systematic name: (4R,4aR,7aR,12bS)-9-hy-droxy-3-methyl-1,2,4,4a,5,6,7a,13-octa-hydro-4,12-methano-benzofuro[3,2-e]iso-quinolin-7-one]. These two crystalline forms, designated as I and II, belong to the P212121 ortho-rhom-bic space group. In both polymorphs, the hydro-morphone mol-ecules adopt very similar conformations with some small differences observed only in the N-methyl amine part of the mol-ecule.
View Article and Find Full Text PDFObjectives: In this study, the advantages and disadvantages of three salt screening methodologies have been explored, and recommendations are put forward as to when each method is most appropriate.
Methods: Three salt screening methodologies have been investigated: the in-situ salt screen, the saturated solution or rational screen approach, and the cooling-evaporative or high-throughput method. Two Active Pharmaceutical Ingredients (APIs) with significant differences in aqueous solubility have been chosen for this study, namely aripiprazole and desvenlafaxine (see Figure 1).
In the crystal structure of a semi-synthetic opioid drug buprenorphine, C29H41NO4 {systematic name: (2S)-2-[(5R,6R,7R,14S)-9α-cyclo-propyl-methyl-3-hy-droxy-6-meth-oxy-4,5-ep-oxy-6,14-ethano-morphinan-7-yl]-3,3-di-methyl-butan-2-ol}, the cyclo-propyl-methyl group is disordered over two sites with an occupancy factor of 0.611 (3) for the major component. One of the hy-droxy groups is involved in intra-molecular O-H⋯O hydrogen bond.
View Article and Find Full Text PDFDeposition of the amyloid-beta peptide is a pathological hallmark of Alzheimer's disease. A high-throughput functional genomics screen identified G protein-coupled receptor 3 (GPR3), a constitutively active orphan G protein-coupled receptor, as a modulator of amyloid-beta production. Overexpression of GPR3 stimulated amyloid-beta production, whereas genetic ablation of GPR3 prevented accumulation of the amyloid-beta peptide in vitro and in an Alzheimer's disease mouse model.
View Article and Find Full Text PDFWe described previously the cDNA cloning of three functional rat histamine H3 receptor (rH3R) isoforms as well as the differential brain expression patterns of their corresponding mRNAs and signaling properties of the resulting rH3A, rH3B, and rH3C receptor isoforms (Mol Pharmacol 59:1-8). In the current report, we describe the cDNA cloning, mRNA localization in the rat central nervous system, and pharmacological characterization of three additional rH3R splice variants (rH3D, rH3E, and rH3F) that differ from the previously published isoforms in that they result from an additional alternative-splicing event. These new H3R isoforms lack the seventh transmembrane (TM) helix and contain an alternative, putatively extracellular, C terminus (6TM-rH3 isoforms).
View Article and Find Full Text PDFIn this study, we replaced the basic amine function of the known histamine H(3) receptor agonists imbutamine or immepip with non-basic alcohol or hydrocarbon moieties. All compounds in this study show a moderate to high affinity for the cloned human H(3) receptor and, unexpectedly, almost all of them act as potent agonists. Moreover, in the alcohol series, we consistently observed an increased selectivity for the human H(3) receptor over the human H(4) receptor, but none of the compounds in this series possess increased affinity and functional activity compared to their alkylamine congeners.
View Article and Find Full Text PDFRNA interference is a powerful tool for studying gene function and for drug target discovery in diverse organisms and cell types. In mammalian systems, small interfering RNAs (siRNAs), or DNA plasmids expressing these siRNAs, have been used to down-modulate gene expression. However, inefficient transfection protocols, in particular, for primary cell types, have hampered the use of these tools in disease-relevant cellular assays.
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