4,139 research outputs found
(2R)-2-Methylpiperazinediium tetrachloridocuprate(II)
In the title compound, (C5H14N2)[CuCl4], the copper(II) ion has a slightly tetrahedrally distorted square-planar coordination geometry and the diprotonated piperazine ring adopts a chair conformation. In the crystal structure, cations and anions are linked by intermolecular N—H⋯Cl hydrogen bonds, forming a three-dimensional network
A dimeric sesquiterpene, gochnatiolide A
The title compound [systematic name: 5′a-hydroxy-1′,3,6,8′-tetrakis(methylene)-3a,4,5,5′,5′a,6,6′,6a,7,7′,7′a,8′,9a,9b,10′a,10′b-hexadecahydrospiro[azuleno[4,5-b]furan-9(2H),3′-[3H]benz[1,8]azuleno[4,5-b]furan]-2,2′,8,9′(1′H,3H,4′H)-tetrone acetone 0.92-solvate], C30H30O7·0.92C3H6O, is a dimeric sequiterpene formed by a cyclohexane system connecting two monomeric sesquiterpene lactone units of dehydrozaluzanin C. It was isolated from Ainsliaea henryi
Contrastive and Generative Graph Convolutional Networks for Graph-based Semi-Supervised Learning
Graph-based Semi-Supervised Learning (SSL) aims to transfer the labels of a
handful of labeled data to the remaining massive unlabeled data via a graph. As
one of the most popular graph-based SSL approaches, the recently proposed Graph
Convolutional Networks (GCNs) have gained remarkable progress by combining the
sound expressiveness of neural networks with graph structure. Nevertheless, the
existing graph-based methods do not directly address the core problem of SSL,
i.e., the shortage of supervision, and thus their performances are still very
limited. To accommodate this issue, a novel GCN-based SSL algorithm is
presented in this paper to enrich the supervision signals by utilizing both
data similarities and graph structure. Firstly, by designing a semi-supervised
contrastive loss, improved node representations can be generated via maximizing
the agreement between different views of the same data or the data from the
same class. Therefore, the rich unlabeled data and the scarce yet valuable
labeled data can jointly provide abundant supervision information for learning
discriminative node representations, which helps improve the subsequent
classification result. Secondly, the underlying determinative relationship
between the data features and input graph topology is extracted as
supplementary supervision signals for SSL via using a graph generative loss
related to the input features. Intensive experimental results on a variety of
real-world datasets firmly verify the effectiveness of our algorithm compared
with other state-of-the-art methods
5,7-Dihydroxy-3,6,8-trimethoxyflavone
The title compound (systematic name: 5,7-dihydroxy-3,6,8-trimethoxy-4H-chromen-4-one), C18H16O7, is a flavone that was isolated from Ainsliaea henryi. There are two molecules in the asymmetric unit, one of which has a disordered methoxy group [occupancy ratio 0.681 (9):0.319 (9)]. Both molecules have an intramolecular O—H⋯O hydrogen bond. In the crystal, molecules are linked into O—H⋯O hydrogen-bonded chains parallel to [110]
Antiarrhythmic and proarrhythmic effects of subcutaneous nerve stimulation in ambulatory dogs
Background
High output subcutaneous nerve stimulation (ScNS) remodels the stellate ganglia and suppresses cardiac arrhythmia.
Objective
To test the hypothesis that long duration low output ScNS causes cardiac nerve sprouting, increases plasma norepinephrine concentration and the durations of paroxysmal atrial tachycardia (PAT) in ambulatory dogs.
Methods
We prospectively randomized 22 dogs (11 males and 11 females) into 5 different output groups for 2 months of ScNS: 0 mA (sham) (N=6), 0.25 mA (N=4), 1.5 mA (N=4), 2.5 mA (N=4) and 3.5 mA (N=4).
Results
As compared with baseline, the changes of the durations of PAT episodes per 48 hours were significantly different among different groups (sham, -5.0±9.5 s; 0.25 mA 95.5±71.0 s; 1.5 mA, -99.3±39.6 s; 2.5 mA, -155.3±87.8 s and 3.5 mA, -76.3±44.8 s, p<0.001). The 3.5 mA group had greater reduction of sinus heart rate than the sham group (-29.8±15.0 bpm vs -14.5±3.0 bpm, p=0.038). Immunohistochemical studies showed that the 0.25 mA group had a significantly increased while 2.5 mA and 3.5 mA stimulation had a significantly reduced growth-associated protein 43 nerve densities in both atria and ventricles. The plasma Norepinephrine concentrations in 0.25 mA group was 5063.0±4366.0 pg/ml, which was significantly higher than other groups of dogs (739.3±946.3, p=0.009). There were no significant differences in the effects of simulation between males and females.
Conclusions
In ambulatory dogs, low output ScNS causes cardiac nerve sprouting, increases plasma norepinephrine concentration and the duration of PAT episodes while high output ScNS is antiarrhythmic
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