Separation devices are widely used in satellites and rockets, where mechanical properties of the devices have significant influences on connection and separation behaviors. Compared to a ...pyrotechnically actuated separation device, a gas-driven separation device employs preloads, instead of explosions, to actuate separation of the aircrafts, which has advantages of reusability and low impacts. Dynamic modeling of the gas-driven separation device can be used to optimize its separation behaviors, where flexibility is considered since preloads stored in deformations play important roles in separations. Complex interactions of interfaces occur during the separation process in a short time, which raises issues of convergence and computational time when a finite element method is in use. In this work, we firstly develop a simplified model of a gas-driven separation device, where flexibility is introduced only on the interfaces of components, and their bodies are still rigid. We apply the LZB multipoint method to deal with repeated impacts of the interfaces in the separation process and establish a variable-constraint technique to rebuild contact-point pairs when contact areas vary. Simulations of the dynamic model describe detailed interactions of the separation process. The results illustrate that the separation time decreases when the preload increases, and the decreasing rate gets lower due to reactions of split nuts. We develop a test bench of the gas-driven separation device, by which experimental results validate that the proposed dynamic model can accurately predict the separation time and speeds at different preloads.
•Functional profiles of microbiota in four mangroves were detected by FAPROTAX as well as C, N, and S gene q-PCR chips.•Some functional groups predicted by FAPROTAX were significantly correlated with ...physicochemical characteristics.•N, C, and S genes detected by q-PCR chip were not impacted by physicochemical characteristics significantly.•The abundance of several N, C, and S cycling genes were significantly higher in Bei, which was the only site with sandy soils.
Mangroves and their global significance in climate change based on the storage of blue carbon and release of CO2, CH4, and N2O have attracted great attention. Microbial communities and their functions are essential for the biogeochemical cycle of carbon (C), nitrogen (N), and sulfur (S). Therefore, the assessment of microbial functions in mangrove habitats, which suffer from different external environments, is necessary to evaluate their unique ecological service functions. In the present work, the functional profiles of microbial communities in four mangrove reserves (one sandy and three muddy, in Beibu Gulf, China) were detected by 16 s RNA gene amplicon-based Functional Annotation of Procaryotic Taxa (FAPROTAX) analysis as well as C, N, and S gene q-PCR chips. The FAPROTAX analysis showed that the metabolic potential in C, N, and S cycling indicated a difference in the four mangrove regions. Moreover, some functional groups involved in N, C, and S cycling were significantly correlated with physicochemical characteristics. However, N, C, and S metabolic genes detected by q-PCR chip did not present the same changes following the variation of environmental conditions as those predicted by the FAPROTAX analysis. Most of the N, C, and S cycling genes were equally distributed in the four mangroves. Several genes involved in N cycling (amoA, amoB, nirK, and nosZ), carbon degradation (amyA, apu, mnp, lig, and chiA), carbon fixation (aclB), and oxidation of H2S (SoxY) were significantly higher in sampling site in Beihai City (Bei), which was the only site with sandy soils. We hypothesized that soil texture (sandy or muddy) rather than physicochemical elements contributes more significantly to the abundance of N, S, and C metabolic genes in mangrove sediment. Our study demonstrated that the change of physicochemical property in mangrove soil was easier to modify the functional microbial groups than functional genes. We should pay attention to the functional redundancy of soil microbiota when using microorganisms as ecological indicator to access the soil activity in mangrove habitats.
Salt tolerance is an important mechanism by which plants can adapt to a saline environment. To understand the process of salt tolerance, we performed global analyses of mRNA alternative ...polyadenylation (APA), an important regulatory mechanism during eukaryotic gene expression, in
and its halophytic relative
with regard to their responses to salt stress. Analyses showed that while APA occurs commonly in both
and
,
possesses fewer APA genes than
(47% vs. 54%). However, the proportion of APA genes was significantly increased in
under salt stress but not in
. This indicated that
is more sensitive to salt stress and that
exhibits an innate response to such conditions. Both species utilized distal poly(A) sites under salt stress; however, only eight genes were found to overlap when their 3' untranslated region (UTR) lengthen genes were compared, thus revealing their distinct responses to salt stress. In
, genes that use distal poly(A) sites were enriched in response to salt stress. However, in
, the use of poly(A) sites was less affected and fewer genes were enriched. The transcripts with upregulated poly(A) sites in
showed enriched pathways in plant hormone signal transduction, starch and sucrose metabolism, and fatty acid elongation; in
, biosynthetic pathways (stilbenoid, diarylheptanoid, and gingerol) and metabolic pathways (arginine and proline) showed enrichment. APA was associated with 42% and 29% of the differentially expressed genes (DE genes) in
and
experiencing salt stress, respectively. Salt specific poly(A) sites and salt-inducible APA events were identified in both species; notably, some salt tolerance-related genes and transcription factor genes exhibited differential APA patterns, such as
and
. Our results suggest that adapted species exhibit more orderly response at the RNA maturation step under salt stress, while more salt-specific poly(A) sites were activated in
to cope with salinity conditions. Collectively, our findings not only highlight the importance of APA in the regulation of gene expression in response to salt stress, but also provide a new perspective on how salt-sensitive and salt-tolerant species perform differently under stress conditions through transcriptome diversity.
In strawberries, fruit set is considered as the transition from the quiescent ovary to a rapidly growing fruit. Auxin, which is produced from the fertilized ovule in the achenes, plays a key role in ...promoting the enlargement of receptacles. However, detailed regulatory mechanisms for fruit set and the mutual regulation between achenes and receptacles are largely unknown. In this study, we found that pollination promoted fruit development (both achene and receptacle), which could be stimulated by exogenous auxin treatment. Interestingly, auxin was highly accumulated in achenes, but not in receptacles, after pollination. Further transcriptome analysis showed that only a small portion of the differentially expressed genes induced by pollination overlapped with those by exogenous auxin treatment. Auxin, but not pollination, was able to activate the expression of growth-related genes, especially in receptacles, which resulted in fast growth. Meanwhile, those genes involved in the pathways of other hormones, such as GA and cytokinin, were also regulated by exogenous auxin treatment, but not pollination. This suggested that pollination was not able to activate auxin responses in receptacles but produced auxin in fertilized achenes, and then auxin might be able to transport or transduce from achenes to receptacles and promote fast fruit growth at the early stage of fruit initiation. Our work revealed a potential coordination between achenes and receptacles during fruit set, and auxin might be a key coordinator.
Microglia play an important role in neuroinflammation and neurodegeneration. Here, we report an approach for generating microglia-containing cerebral organoids derived from human pluripotent stem ...cells involving the supplementation of growth factors (FGF, EGF, heparin) and 10% CO2 culture conditions. Using this platform, Western Pacific Amyotrophic Lateral Sclerosis and Parkinsonism–Dementia Complex (ALS-PDC) cerebral organoids were generated from patient-derived induced pluripotent stem cells (iPSCs). These ALS-PDC-affected organoids had more reactive astrocytes and M1 microglia, and had fewer M2 microglia than their unaffected counterparts, leading to impaired microglia-mediated phagocytosis. RNA-seq analysis of ALS-PDC and control organoids indicated that the most significant changes were microglia- and astrocyte-related genes (IFITM1/2, TGF-β, and GFAP). The most significantly downregulated pathway was type I interferon signaling. Interferon-gamma supplementation increased IFITM expression, enhanced microglia-mediated phagocytosis, and reduced beta-amyloid accumulation in ALS-PDC-affected network. The results demonstrated the feasibility of using microglia-containing organoids for the study of neurodegenerative diseases.
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•Report an approach for the generation of microglia-containing cerebral organoids•Cerebral organoids derived from ALS-PDC patient had fewer M2 state microglia•Transcriptome analysis indicated that type I interferon signaling was downregulated•Interferon−γ supplementation promoted IFITM expression and M2 microglia polarization
Neuroscience; Immunology; Cell biology; Stem cells research
Sparse view computed tomography (SVCT) aims to reduce the number of X-ray projection views required for reconstructing the cross-sectional image of an object. While SVCT significantly reduces X-ray ...radiation dose and speeds up scanning, insufficient projection data give rise to issues such as severe streak artifacts and blurring in reconstructed images, thereby impacting the diagnostic accuracy of CT detection. To address this challenge, a dual-domain reconstruction network incorporating multi-level wavelet transform and recurrent convolution is proposed in this paper. The dual-domain network is composed of a sinogram domain network (SDN) and an image domain network (IDN). Multi-level wavelet transform is employed in both IDN and SDN to decompose sinograms and CT images into distinct frequency components, which are then processed through separate network branches to recover detailed information within their respective frequency bands. To capture global textures, artifacts, and shallow features in sinograms and CT images, a recurrent convolution unit (RCU) based on convolutional long and short-term memory (Conv-LSTM) is designed, which can model their long-range dependencies through recurrent calculation. Additionally, a self-attention-based multi-level frequency feature normalization fusion (MFNF) block is proposed to assist in recovering high-frequency components by aggregating low-frequency components. Finally, an edge loss function based on the Laplacian of Gaussian (LoG) is designed as the regularization term for enhancing the recovery of high-frequency edge structures. The experimental results demonstrate the effectiveness of our approach in reducing artifacts and enhancing the reconstruction of intricate structural details across various sparse views and noise levels. Our method excels in both performance and robustness, as evidenced by its superior outcomes in numerous qualitative and quantitative assessments, surpassing contemporary state-of-the-art CNNs or Transformer-based reconstruction methods.
The supplementation of fish feed with fermented soybean meal (FSBM) as an additive is widely used to produce aquatic feed. However, the mechanism by which FSBM regulates gut microbes in fish are ...still largely unknown. In the present work, soybean meal fermented by Lactobacillus fermentum (Lactobacillus group), Bacillus natto (Bacillus group), and Saccharomyces cerevisiae (Saccharomyces group) was added to fish diets, and the effects of these diets on gut microbiota, growth performance Weight gain rate (WGR) and Specific growth rate (SGR), and immunity superoxide dismutase (SOD), lysozyme (LSZ) and alkaline phosphatase (AKP) of Nile tilapia was assessed. Compared with Nontreated group, Lactobacillus and Saccharomyces fermented soybean meal remarkably improved the WGR, SGR, AKP, and LSZ (p < 0.05). The SOD activity was significantly lower in Bacillus group than other groups (p < 0.05). High-throughput sequencing of the V3-V4 region of the 16S rRNA gene was used to analyze the gut microbiota of Nile tilapia. PCoA and UPGMA showed that the similarity between the Saccharomyces and Lactobacillus groups was higher. Compared with Nontreated group, Lactobacillus fermented soybean meal significantly increased the Chao1 index and number of observed species (p < 0.05), while Bacillus fermented soybean meal remarkably improved the Simpson and Shannon indices (p < 0.01). Corynebacterium and Mycobacterium were significantly enriched in the Saccharomyces and Lactobacillus groups, and Aquabacterium and Acidovorax were significantly enriched in the Bacillus group. LEfSe analysis showed that Rhizobiales, Thermomicrobia, Myxococcales and Gemmatales were the biomarker in Lactobacillus group, Mycobacterium, Clavibacter and Coxiellaceae were the biomarker in Saccharomyces group, and Brevundimonas and Aquabacterium were the biomarker in Bacillus group. More interestingly, the co-occurrence network indicated that fish diets supplemented with L. fermentum or S. cerevisiae fermented soybean meal were more likely to impact some species that played pivotal roles in the network. L. fermentum- or S. cerevisiae- fermented SBM tended to activate similar “big team” species and promote their cooperation to perform certain functions. This research showed that FSBM fermented by L. fermentum, B. natto, and S. cerevisiae exerted different effect on growth, immunity, and gut microbiota of Nile tilapia, and the co-occurrence network of the microbiota could partially explain the relationship between the growth performance and immune parameters and the microbiomic data.
•Lactobacillus fermentum or Saccharomyces cerevisiae fermented soybean meal (FSBM) enhanced the growth and immune parameters of Nile tilapia.•FSBM based diets increased the alpha diversity of microbiota in the gut of Nile tilapia.•The similarity of gut microbiota between L. fermentum and S. cerevisiae FSBM treated Nile tilapia was higher than B. natto and control group.•L. fermentum or S. cerevisiae FSBM tended to activate big co-occurrence network of gut microbiota and promote their cooperation
•Rice cannot synthesize ginsenosides or sapogenins without DS and βAS.•This is the first report on transforming ginseng DS gene into rice.•The ginseng rice germplasm containing dammarane-type ...sapogenins was obtained.
Ginsenosides are the main active ingredients in Chinese medicinal ginseng; 2,3-oxidosqualene is a precursor metabolite to ginsenosides that is present in rice. Because rice lacks a key rate-limiting enzyme (dammarenediol-II synthase, DS), rice cannot synthesize dammarane-type ginsenosides. In this study, the ginseng (Panax ginseng CA Mey.) DS gene (GenBank: AB265170.1) was transformed into rice using agrobacterium, and 64 rice transgenic plants were produced. The Transfer-DNA (T-DNA) insertion sites in homozygous lines of the T2 generation were determined by using high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR) and differed in all tested lines. One to two copies of the T-DNA were present in each transformant, and real-time PCR and Western blotting showed that the transformed DS gene could be transcribed and highly expressed. High performance liquid chromatography (HPLC) analysis showed that the dammarane-type sapogenin 20(S)-protopanaxadiol (PPD) content was 0.35–0.59mg/g dw and the dammarane-type sapogenin 20(S)-protopanaxatriol (PPT) content was 0.23–0.43mg/g dw in the transgenic rice. LC/MS analysis confirmed production of PPD and PPT. These results indicate that a new “ginseng rice” germplasm containing dammarane-type sapogenins has been successfully developed by transforming the ginseng DS gene into rice.
Alternative polyadenylation (APA) occurs in the process of mRNA maturation by adding a poly(A) tail at different locations, resulting increased diversity of mRNA isoforms and contributing to the ...complexity of gene regulatory network. Benefit from the development of high-throughput sequencing technologies, we could now delineate APA profiles of transcriptomes at an unprecedented pace. Especially the single cell RNA sequencing (scRNA-seq) technologies provide us opportunities to interrogate biological details of diverse and rare cell types. Despite increasing evidence showing that APA is involved in the cell type-specific regulation and function, efficient and specific laboratory methods for capturing poly(A) sites at single cell resolution are underdeveloped to date. In this review, we summarize existing experimental and computational methods for the identification of APA dynamics from diverse single cell types. A future perspective is also provided.
Auxin is a crucial hormone that regulates various aspects of plant growth and development. It exerts its effects through multiple signaling pathways, including the TIR1/AFB-based transcriptional ...regulation in the nucleus. However, the specific role of auxin receptors in determining developmental features in the strawberry (
) remains unclear. Our research has identified FveAFB5, a potential auxin receptor, as a key player in the development and auxin responses of woodland strawberry diploid variety Hawaii 4. FveAFB5 positively influences lateral root development, plant height, and fruit development, while negatively regulating shoot branching. Moreover, the mutation of
confers strong resistance to the auxinic herbicide picloram, compared to dicamba and quinclorac. Transcriptome analysis suggests that FveAFB5 may initiate auxin and abscisic acid signaling to inhibit growth in response to picloram. Therefore, FveAFB5 likely acts as an auxin receptor involved in regulating multiple processes related to strawberry growth and development.
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