1,254 research outputs found
2,4-Bis(2-methoxyphenyl)-3-azabicyclo[3.3.1]nonan-9-one
In the title compound, C22H25NO3, the molecule has a pseudo-mirror plane. The structure is a positional isomer of 2,4-bis(4-methoxyphenyl)-3-azabicyclo[3.3.1]nonan-9-one [Cox, McCabe, Milne & Sim (1985 ▶). J. Chem. Soc. Chem. Commun. pp. 626–628]. The 3-azabicyclo[3.3.1]nonan-9-one moiety adopts a double chair conformation with equatorial orientations of both 2-methoxyphenyl substituents on either side of the secondary amino group. The benzene rings are oriented at an angle of 33.86 (4)° with respect to each other and the methoxy groups point towards the carbonyl group. The crystal structure is stabilized by intermolecular N—H⋯π interactions
Solving Continual Combinatorial Selection via Deep Reinforcement Learning
We consider the Markov Decision Process (MDP) of selecting a subset of items
at each step, termed the Select-MDP (S-MDP). The large state and action spaces
of S-MDPs make them intractable to solve with typical reinforcement learning
(RL) algorithms especially when the number of items is huge. In this paper, we
present a deep RL algorithm to solve this issue by adopting the following key
ideas. First, we convert the original S-MDP into an Iterative Select-MDP
(IS-MDP), which is equivalent to the S-MDP in terms of optimal actions. IS-MDP
decomposes a joint action of selecting K items simultaneously into K iterative
selections resulting in the decrease of actions at the expense of an
exponential increase of states. Second, we overcome this state space explo-sion
by exploiting a special symmetry in IS-MDPs with novel weight shared
Q-networks, which prov-ably maintain sufficient expressive power. Various
experiments demonstrate that our approach works well even when the item space
is large and that it scales to environments with item spaces different from
those used in training.Comment: Accepted to IJCAI 2019,14 pages,8 figure
2,4-Bis(2-bromophenyl)-3-azabicyclo[3.3.1]nonan-9-one
In the molecular structure of the title compound, C20H19Br2NO, the fused six-membered heterocyclic and cyclohexane rings adopt a twin-chair conformation with equatorial orientations of all the substituents. Both the ortho-bromo substituents of the benzene rings are oriented towards the carbonyl group; the dihedral angle between the ring planes is 29.13 (3)°. In the crystal structure, the N—H group does not participate in any hydrogen bonds
Patch-Mix Contrastive Learning with Audio Spectrogram Transformer on Respiratory Sound Classification
Respiratory sound contains crucial information for the early diagnosis of
fatal lung diseases. Since the COVID-19 pandemic, there has been a growing
interest in contact-free medical care based on electronic stethoscopes. To this
end, cutting-edge deep learning models have been developed to diagnose lung
diseases; however, it is still challenging due to the scarcity of medical data.
In this study, we demonstrate that the pretrained model on large-scale visual
and audio datasets can be generalized to the respiratory sound classification
task. In addition, we introduce a straightforward Patch-Mix augmentation, which
randomly mixes patches between different samples, with Audio Spectrogram
Transformer (AST). We further propose a novel and effective Patch-Mix
Contrastive Learning to distinguish the mixed representations in the latent
space. Our method achieves state-of-the-art performance on the ICBHI dataset,
outperforming the prior leading score by an improvement of 4.08%.Comment: INTERSPEECH 2023, Code URL:
https://github.com/raymin0223/patch-mix_contrastive_learnin
Regulation of Pituitary Adenylate Cyclase-activating Polypeptide Gene Transcription by TTF-1, a Homeodomain-containing Transcription Factor
Pituitary adenylate cyclase-activating polypeptide (PACAP) is an important hypophysiotrophic factor as well as a regulator for immune, reproductive, and neural tissues. We recently found that TTF-1, a homeodomain-containing transcription factor essential for the development of the fetal diencephalon, is postnatally expressed in the hypothalamic area and plays a transcription regulatory role for certain neurohormones. Based on the similarity of synthesis sites between PACAP and TTF-1 and, moreover, on the presence of conserved core TTF-1 binding motifs in the 5′-flanking region of the PACAP gene, we sought to uncover a regulatory role of TTF-1 in PACAP gene transcription. The TTF-1 homeodomain binds to six of the seven putative binding domains observed in the 5′-flanking region of the PACAP gene. In the C6 glioma cell-line, TTF-1 activates the PACAP promoter in a dose-dependent manner. This transactivation of PACAP by TTF-1 was totally removed when the core TTF-1 binding motif at −369 was deleted. RNase protection assays showed that TTF-1 and PACAP mRNAs have daily fluctuations in the rat hypothalamus. They both were at low levels during the day and high levels during the night. Intracerebroventricular administration of an antisense TTF-1 oligodeoxynucleotide significantly decreased the PACAP mRNA level as well as TTF-1 protein content in the rat hypothalamus, suggesting that TTF-1 also regulates PACAP transcription in vivo. Moreover, the TTF-1 promoter was inhibited by molecular oscillators of CLOCK and BMAL-1. Taken together, these data suggest that TTF-1 plays an important regulatory role in the gene transcription for PACAP, which may be important for the generation of a daily rhythm of hypothalamic PACAP gene expression
Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea
The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser83→Arg83 or Ser83→Asn83. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida
Edematous and painful external hemorrhoids following intersphincteric resection for low rectal cancer
Intersphincteric resection (ISR) is the ultimate sphincter saving procedure for low rectal cancer. Hemorrhoids are a common benign condition. We present and discuss a case of ISR which developed painful edematous hemorrhoids after ISR. A 62-year-old female with low rectal cancer received neoadjuvant chemoradiotherapy with successful down staging of tumor before undergoing robot assisted ISR with coloanal hand-sewn anastomosis. She had pre-existing external hemorrhoids which were not excised. She developed painful and edematous external hemorrhoids 4 days after surgery. These were treated conservatively before discharge. Many colorectal surgeons performing ISR have experienced similar situations in their patients, but none have reported on this phenomenon. We discuss the possible factors that may contribute to this situation. A possible solution is prophylactic excision of the hemorrhoids during coloanal anastomosis. Painful hemorrhoids may occur after ISR and if managed conservatively, the outcome is skin tags
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