Femtosecond lasers have been applied to machining of zirconia (ZrO
2
) ceramics because of their ultrashort pulse duration and high peak power. However, an unclear understanding of the ultrafast ...laser–material interaction mechanisms limits the achievement of precision processing. In this study, a pump-probe imaging method comprising a focusing probe beam integrated with a high-speed camera was developed to directly observe and quantitatively evaluate the multi-timescale transient processing phenomena, including electron excitation, shockwave propagation, plasma evolution, and hole formation, occurring on the picosecond to second timescales, inside a ZrO
2
sample. The variation mechanism in the shapes, lifetimes, and dimensions of these phenomena and their impacts on the drilling performance under different laser parameters were explored. The clear imaging and investigation of the above phenomena contribute to revealing the ultrafast laser–material interaction mechanisms and precision processing in the laser-drilling of zirconia ceramics.
Most current approaches to analyse metagenomic data rely on reference genomes. Novel microbial communities extend far beyond the coverage of reference databases and de novo metagenome assembly from ...complex microbial communities remains a great challenge. Here we present a novel experimental and bioinformatic framework, metaSort, for effective construction of bacterial genomes from metagenomic samples. MetaSort provides a sorted mini-metagenome approach based on flow cytometry and single-cell sequencing methodologies, and employs new computational algorithms to efficiently recover high-quality genomes from the sorted mini-metagenome by the complementary of the original metagenome. Through extensive evaluations, we demonstrated that metaSort has an excellent and unbiased performance on genome recovery and assembly. Furthermore, we applied metaSort to an unexplored microflora colonized on the surface of marine kelp and successfully recovered 75 high-quality genomes at one time. This approach will greatly improve access to microbial genomes from complex or novel communities.
Bovine viral diarrhoea virus (BVDV) is the member of the genus Pestivirus within the Flaviviridae family and responsible for severe economic losses in the cattle industry. BVDV can employ ...'infect-and-persist' strategy and 'hit-and-run' strategy to remain associated with hosts and thus contributes to BVDV circulation in cattle herds. BVDV have also evolved various strategies to evade the innate immunity of host. To further understand the mechanisms by which BVDV overcomes the host cell innate immune response and provide more clues for further understanding the BVDV-host interaction, in this descriptive study, we conducted a investigation of differentially expressed genes (DEGs) of the host during BVDV infection by RNA-Seq analysis.
Our analysis identified 1297, 1732, 3072, and 1877 DEGs in the comparison groups mock vs. MDBK cells infected with BVDV post 2 h (MBV2h), mock vs. MBV6h, mock vs. MBV12h, and mock vs. MBV24h, respectively. The reproducibility and repeatability of the results were validated by RT-qPCR. Enrichment analyses of GO annotations and KEGG pathways revealed the host DEGs that are potentially induced by BVDV infection and may participate in BVDV-host interactions. Protein-protein interaction (PPI) network analyses identified the potential interactions among the DEGs. Our findings suggested that BVDV infection induced the upregulation of genes involved in lipid metabolism. The expression of genes that have antiviral roles, including ISG15, Mx1, OSA1Y, were found to be downregulated and are thus potentially associated with the inhibition of host innate immune system during BVDV infection. The expression levels of F3, C1R, KNG1, CLU, C3, FB, SERPINA5, SERPINE1, C1S, F2RL2, and C2, which belong to the complement and coagulation signalling cascades, were downregulated during BVDV infection, which suggested that the complement system might play a crucial role during BVDV infection.
In this descriptive study, our findings revealed the changes in the host transcriptome expression profile during BVDV infection and suggested that BVDV-infection induced altering the host's metabolic network, the inhibition of the expression of antiviral proteins and genes within the complement system might be contributed to BVDV proliferation. The above findings provided unique insights for further studies on the mechanisms underlying BVDV-host interactions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Manila clam Ruditapesphilippinarum is one of the most economically important marine shellfish. However, the molecular mechanisms of early development in Manila clams are largely unknown. In this ...study, we collected samples from 13 stages of early development in Manila clam and compared the mRNA expression pattern between samples by RNA-seq techniques. We applied RNA-seq technology to 13 embryonic and larval stages of the Manila clam to identify critical genes and pathways involved in their development and biological characteristics. Important genes associated with different morphologies during the early fertilized egg, cell division, cell differentiation, hatching, and metamorphosis stages were identified. We detected the highest number of differentially expressed genes in the comparison of the pediveliger and single pipe juvenile stages, which is a time when biological characteristics greatly change during metamorphosis. Gene Ontology (GO) enrichment analysis showed that expression levels of microtubule protein-related molecules and Rho genes were upregulated and that GO terms such as ribosome, translation, and organelle were enriched in the early development stages of the Manila clam. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the foxo, wnt, and transforming growth factor-beta pathways were significantly enriched during early development. These results provide insights into the molecular mechanisms at work during different periods of early development of Manila clams. These transcriptomic data provide clues to the molecular mechanisms underlying the development of Manila clam larvae. These results will help to improve Manila clam reproduction and development.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
During metal additive manufacturing, the porosity of the as-built part deteriorates the mechanical property and even hinders the further application of metal additive manufacturing. ...Particularly, the mechanisms of keyhole pores associated with the keyhole fluctuation are not fully understood. To reveal the mechanisms of the keyhole pores formation, we adopt a multiphysics thermal-fluid flow model incorporating heat transfer, liquid flow, metal evaporation, Marangoni effect, and Darcy’s law to simulate the keyhole pore formation process, and the results are validated with the in situ X-ray images. The simulation results present the instant bubble formation due to the keyhole instability and motion of the instant bubble pinning on the solidification front. Furthermore, comparing the keyhole pore formation under different laser scanning speeds shows that the keyhole pore is sensitive to the manufacturing parameters. Additionally, the simulation under a low ambient pressure shows the feasibility of improving the keyhole stability to reduce and even avoid the formation of keyhole pores.
Machining performance of thin-walled components made by aeronautical difficult-to-process materials is a significant issue in the aviation manufacturing industry. Although wire electric discharge ...machining-low speed (WEDM-LS) is one of typical non-contact machining processes without macro cutting force, which does well in removing hardness and brittleness materials via pulsed discharge at high temperature, but few researchers have studied the thermal distortion behavior leading to a considerable geometric error in the WEDM-LS of thin-walled components. In this paper, a transverse magnetic field assisted method is applied for affecting the uniformity of discharge point distribution so as to reduce the distortion in WEDM-LS processing thin-wall component. First, the generation mechanism of this new distortion behavior and the impact mechanism of transverse magnetic field (TMF) on distortion are demonstrated by theoretical analysis. In order to further figure out the distortion behavior in the TMF-WEDM process, a new thermo-physical model considering the discharge point distribution is established to simulate temperature field, residual stress field and distortion profiles. Then a large number of Taguchi experiments are carried out to investigate the influences of process parameters including pulse discharge energy (pulse on time, pulse off time, and current) and magnetic field strength on distortion in WEDM-LS. To comparatively analyze simulated and experimental results, the accuracy of established thermo-physical model is verified within a relative error of 18.38 % in distortion. Moreover, it can be revealed that transverse magnetic field contribute to significantly improve the longitudinal distribution uniformity with maximum increase of 12.32% at magnetic field strength: 0.15 T, leading to significant reductions of 32.77% in distortion and 22.68% in recast layer. Eventually, we also presented the variation of residual stress and recast layer along thickness direction under different distortion behavior, which are in good agreement with that of distortion behavior.
Rice SUT and SWEET Transporters Hu, Zhi; Tang, Zhenjia; Zhang, Yanming ...
International journal of molecular sciences,
10/2021, Letnik:
22, Številka:
20
Journal Article
Recenzirano
Odprti dostop
Sugar transporters play important or even indispensable roles in sugar translocation among adjacent cells in the plant. They are mainly composed of sucrose-proton symporter SUT family members and ...SWEET family members. In rice, 5 and 21 members are identified in these transporter families, and some of their physiological functions have been characterized on the basis of gene knockout or knockdown strategies. Existing evidence shows that most SUT members play indispensable roles, while many SWEET members are seemingly not so critical in plant growth and development regarding whether their mutants display an aberrant phenotype or not. Generally, the expressions of
and
genes focus on the leaf, stem, and grain that represent the source, transport, and sink organs where carbohydrate production, allocation, and storage take place. Rice SUT and SWEET also play roles in both biotic and abiotic stress responses in addition to plant growth and development. At present, these sugar transporter gene regulation mechanisms are largely unclear. In this review, we compare the expressional profiles of these sugar transporter genes on the basis of chip data and elaborate their research advances. Some suggestions concerning future investigation are also proposed.
Through population expansion and accidental or deliberate introduction, prey commonly encounter novel predators they had never seen before. Several studies have shown that animals can generalize ...their learned recognition of a familiar predator to novel ones according to predators' identical or similar features. This process in fish mainly depends on the visual and chemosensory cues they receive. However, there is a lack of understanding of the different effects of these two cues. Topmouth gudgeons (
) that had never seen turtles were captured and used as the subjects, and three freshwater turtles of different genera were used as predators. Before and after using one turtle for predator training treatment of topmouth gudgeons, fish responses to visual and chemosensory cues of each turtle were tested and recorded, and it was found that predator training promoted topmouth gudgeons' recognition of the risks represented by visual cues of all three turtles and by chemosensory cues of the turtle that were used in training. These results further verify the generalization of predator recognition in fish and indicate that visual cues have a more extensive effect on fish than chemosensory cues in identifying novel predators, especially predators that are distantly related to the familiar threats.
Both geopolymer and plant fiber (PF) meet the requirements of sustainable development. Geopolymers have the advantages of simple preparation process, conservation and environmental protection, high ...early strength, wide source of raw materials, and low cost. They have broad application prospects and are considered as the most potential cementitious materials to replace cement. However, due to the ceramic-like shape and brittleness of geopolymers, their flexural strength and tensile strength are poor, and they are sensitive to microcracks. In order to solve the brittleness problem of geopolymers, the toughness of composites can be improved by adding fibers. Adding fibers to geopolymers can limit the growth of cracks and enhance the ductility, toughness and tensile strength of geopolymers. PF is a good natural polymer material, with the advantages of low density, high aspect ratio. It is not only cheap, easy to obtain, abundant sources, but also can be repeatedly processed and biodegradable. PF has high strength and low hardness, which can improve the toughness of composites. Nowadays, the research and engineering application of plant fiber-reinforced geopolymers (PFRGs) are more and more extensive. In this paper, the recent studies on mechanical properties of PFRGs were reviewed. The characteristics of plant fibers and the composition, structure and properties of geopolymers were reviewed. The compatibility of geopolymer material and plant fiber and the degradation of fiber in the substrate were analyzed. From the perspective of the effect of plant fibers on the compression, tensile and bending properties of geopolymer, the reinforcing mechanism of plant fibers on geopolymer was analyzed. Meanwhile, the effect of PF pretreatment on the mechanical properties of the PFRGs was analyzed. Through the comprehensive analysis of PFFRGs, the limitations and recommendations of PFFRG are put forward.
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