442 research outputs found
Synthesis and Evaluation of Some Steroidal Oximes as Cytotoxic Agents: Structure/Activity Studies (I)
The side chain of a compound plays an important role in its biological function. In our studies, we have found that hydroximinosteroid derivatives with different side chains and position of hydroximino on ring A and B displayed remarkable distinct cytotoxicities against a diversity of cancer cell types. Presence of an oxime group on ring B and a hydroxy on ring A or B resulted in a higher cytotoxicity than other structural motifs. In addition, a cholesterol-type side chain at position 17 was required for the biological activity. Our findings provide new evidence showing the relationship between the chemical structure and biological function. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs
Furnishing Sound Event Detection with Language Model Abilities
Recently, the ability of language models (LMs) has attracted increasing
attention in visual cross-modality. In this paper, we further explore the
generation capacity of LMs for sound event detection (SED), beyond the visual
domain. Specifically, we propose an elegant method that aligns audio features
and text features to accomplish sound event classification and temporal
location. The framework consists of an acoustic encoder, a contrastive module
that align the corresponding representations of the text and audio, and a
decoupled language decoder that generates temporal and event sequences from the
audio characteristic. Compared with conventional works that require complicated
processing and barely utilize limited audio features, our model is more concise
and comprehensive since language model directly leverage its semantic
capabilities to generate the sequences. We investigate different decoupling
modules to demonstrate the effectiveness for timestamps capture and event
classification. Evaluation results show that the proposed method achieves
accurate sequences of sound event detection.Comment: 8 pages,2 figures,published to AAA
Synthesis and Evaluation of Some Steroidal Oximes as Cytotoxic Agents: Structure/Activity Studies (I)
The side chain of a compound plays an important role in its biological function. In our studies, we have found that hydroximinosteroid derivatives with different side chains and position of hydroximino on ring A and B displayed remarkable distinct cytotoxicities against a diversity of cancer cell types. Presence of an oxime group on ring B and a hydroxy on ring A or B resulted in a higher cytotoxicity than other structural motifs. In addition, a cholesterol-type side chain at position 17 was required for the biological activity. Our findings provide new evidence showing the relationship between the chemical structure and biological function. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs
High Frankia abundance and low diversity of microbial community are associated with nodulation specificity and stability of sea buckthorn root nodule
IntroductionActinorhizal symbioses are gaining attention due to the importance of symbiotic nitrogen fixation in sustainable agriculture. Sea buckthorn (Hippophae L.) is an important actinorhizal plant, yet research on the microbial community and nitrogen cycling in its nodules is limited. In addition, the influence of environmental differences on the microbial community of sea buckthorn nodules and whether there is a single nitrogen-fixing actinomycete species in the nodules are still unknown.MethodsWe investigated the diversity, community composition, network associations and nitrogen cycling pathways of the microbial communities in the root nodule (RN), nodule surface soil (NS), and bulk soil (BS) of Mongolian sea buckthorn distributed under three distinct ecological conditions in northern China using 16S rRNA gene and metagenomic sequencing. Combined with the data of environmental factors, the effects of environmental differences on different sample types were analyzed. ResultsThe results showed that plants exerted a clear selective filtering effect on microbiota, resulting in a significant reduction in microbial community diversity and network complexity from BS to NS to RN. Proteobacteria was the most abundant phylum in the microbiomes of BS and NS. While RN was primarily dominated by Actinobacteria, with Frankia sp. EAN1pec serving as the most dominant species. Correlation analysis indicated that the host determined the microbial community composition in RN, independent of the ecological and geographical environmental changes of the sea buckthorn plantations. Nitrogen cycle pathway analyses showed that RN microbial community primarily functions in nitrogen fixation, and Frankia sp. EAN1pec was a major contributor to nitrogen fixation genes in RN.DiscussionThis study provides valuable insights into the effects of eco-geographical environment on the microbial communities of sea buckthorn RN. These findings further prove that the nodulation specificity and stability of sea buckthorn root and Frankia sp. EAN1pec may be the result of their long-term co-evolution
Audio Generation with Multiple Conditional Diffusion Model
Text-based audio generation models have limitations as they cannot encompass
all the information in audio, leading to restricted controllability when
relying solely on text. To address this issue, we propose a novel model that
enhances the controllability of existing pre-trained text-to-audio models by
incorporating additional conditions including content (timestamp) and style
(pitch contour and energy contour) as supplements to the text. This approach
achieves fine-grained control over the temporal order, pitch, and energy of
generated audio. To preserve the diversity of generation, we employ a trainable
control condition encoder that is enhanced by a large language model and a
trainable Fusion-Net to encode and fuse the additional conditions while keeping
the weights of the pre-trained text-to-audio model frozen. Due to the lack of
suitable datasets and evaluation metrics, we consolidate existing datasets into
a new dataset comprising the audio and corresponding conditions and use a
series of evaluation metrics to evaluate the controllability performance.
Experimental results demonstrate that our model successfully achieves
fine-grained control to accomplish controllable audio generation. Audio samples
and our dataset are publicly available at
https://conditionaudiogen.github.io/conditionaudiogen/Comment: Submitted to AAAI 202
Morphological and molecular evidence for functional organization along the rostrocaudal axis of the adult zebrafish intestine
Background
The zebrafish intestine is a simple tapered tube that is folded into three sections. However, whether the intestine is functionally similar along its length remains unknown. Thus, a systematic structural and functional characterization of the zebrafish intestine is desirable for future studies of the digestive tract and the intestinal biology and development.
Results
To characterize the structure and function of the adult zebrafish intestine, we divided the intestine into seven roughly equal-length segments, S1-S7, and systematically examined the morphology of the mucosal lining, histology of the epithelium, and molecular signatures from transcriptome analysis. Prominent morphological features are circumferentially-oriented villar ridges in segments S1-S6 and the absence of crypts. Molecular characterization of the transcriptome from each segment shows that segments S1-S5 are very similar while S6 and S7 unique. Gene ontology analyses reveal that S1-S5 express genes whose functions involve metabolism of carbohydrates, transport of lipids and energy generation, while the last two segments display relatively limited function. Based on comparative Gene Set Enrichment Analysis, the first five segments share strong similarity with human and mouse small intestine while S6 shows similarity with human cecum and rectum, and S7 with human rectum. The intestinal tract does not display the anatomical, morphological, and molecular signatures of a stomach and thus we conclude that this organ is absent from the zebrafish digestive system.
Conclusions
Our genome-wide gene expression data indicate that, despite the lack of crypts, the rostral, mid, and caudal portions of the zebrafish intestine have distinct functions analogous to the mammalian small and large intestine, respectively. Organization of ridge structures represents a unique feature of zebrafish intestine, though they produce similar cross sections to mammalian intestines. Evolutionary lack of stomach, crypts, Paneth cells and submucosal glands has shaped the zebrafish intestine into a simpler but unique organ in vertebrate intestinal biology.Singapore-MIT Alliance for Research and TechnologySingapore. Biomedical Research CouncilNational University of Singapor
- …