44 research outputs found
A Novel Strategy of US3 Codon De-Optimization for Construction of an Attenuated Pseudorabies Virus against High Virulent Chinese Pseudorabies Virus Variant
In this study, we applied bacterial artificial chromosome (BAC) technology with PRVĪTK/gE/gI as the base material to replace the first, central, and terminal segments of the US3 gene with codon-deoptimized fragments via two-step Red-mediated recombination in E. coli GS1783 cells. The three constructed BACs were co-transfected with gI and part of gE fragments carrying homologous sequences (gI+gEā), respectively, in swine testicular cells. These three recombinant viruses with US3 codon de-optimization ((PRVĪTK&gE-US3deopā1, PRVĪTK&gE-US3deopā2, and PRVĪTK&gE-US3deopā3) were obtained and purified. These three recombinant viruses exhibited similar growth kinetics to the parental AH02LA strain, stably retained the deletion of TK and gE gene fragments, and stably inherited the recoded US3. Mice were inoculated intraperitoneally with the three recombinant viruses or control virus PRVĪTK&gEAH02 at a 107.0 TCID50 dose. Mice immunized with PRVĪTK&gE-US3deopā1 did not develop clinical signs and had a decreased virus load and attenuated pathological changes in the lungs and brain compared to the control group. Moreover, immunized mice were challenged with 100 LD50 of the AH02LA strain, and PRVĪTK&gE-US3deopā1 provided similar protection to that of the control virus PRVĪTK&gEAH02. Finally, PRVĪTK&gE-US3deopā1 was injected intramuscularly into 1-day-old PRV-negative piglets at a dose of 106.0 TCID50. Immunized piglets showed only slight temperature reactions and mild clinical signs. However, high levels of seroneutralizing antibody were produced at 14 and 21 days post-immunization. In addition, the immunization of PRVĪTK&gE-US3deopā1 at a dose of 105.0 TCID50 provided complete clinical protection and prevented virus shedding in piglets challenged by 106.5 TCID50 of the PRV AH02LA variant at 1 week post immunization. Together, these findings suggest that PRVĪTK&gE-US3deopā1 displays great potential as a vaccine candidate
Aggregation-Induced Emission (AIE), Life and Health
Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health
Comparative analysis of miRNAs and their target transcripts between a spontaneous late-ripening sweet orange mutant and its wild-type using small RNA and degradome sequencing
Fruit ripening in citrus is not well understood at the molecular level. Knowledge of the regulatory mechanism of citrus fruit ripening at the post-transcriptional level in particular is lacking. Here, we comparatively analyzed the miRNAs and their targeted genes in a spontaneous late-ripening mutant, āFengwanā sweet orange (MT) (Citrus sinensis L. Osbeck), and its wild-type counterpart ('Fengjie 72-1', WT). Using high-throughput sequencing of small RNAs and RNA degradome tags, we identified 107 known and 21 novel miRNAs, as well as 225 target genes. A total of 24 miRNAs (16 known miRNAs and 8 novel miRNAs) were shown to be differentially expressed between MT and WT. The expression pattern of several key miRNAs and their target genes during citrus fruit development and ripening stages was examined. Csi-miR156k, csi-miR159 and csi-miR166d suppressed specific transcription factors (GAMYBs, SPLs and ATHBs) that are supposed to be important regulators involved in citrus fruit development and ripening. In the present study, miRNA-mediated silencing of target genes was found under complicated and sensitive regulation in citrus fruit. The identification of miRNAs and their target genes provide new clues for future investigation of mechanisms that regulate citrus fruit ripening
Characteristics of Atmospheric Kinetic Energy Spectra during the Intensification of Typhoon Lekima (2019)
The intensification of Typhoon Lekima (2019) is simulated with the Weather Research and Forecasting model to study the atmospheric horizontal kinetic energy (HKE) spectra and corresponding spectral HKE budgets under the control of real tropical cyclone (TC). The results show that the TC has the ability to modify the canonical atmospheric energy spectrum during its evolution, which is dominated by its rotational mode. With the intensification of Lekima, the HKE spectrum in the troposphere swells over the central mesoscale and develops an arc-like shape. The stronger the TC, the more pronounced the arc-like shape is and the smaller scale it extends to. The roles various physical processes play at different heights and horizontal scales during the intensification of Lekima are investigated and the dependence of the effect of physical processes on scale and height is revealed. Meanwhile, the potential relationship between the intensification of TC, the activation of energy activity at smaller scales, and the downscale extension of the arc-like spectral shape is found
Pseudo-Data based Self-Supervised Federated Learning for Classification of Histopathological Images
Computer-aided diagnosis (CAD) can help pathologists improve diagnostic
accuracy together with consistency and repeatability for cancers. However, the
CAD models trained with the histopathological images only from a single center
(hospital) generally suffer from the generalization problem due to the
straining inconsistencies among different centers. In this work, we propose a
pseudo-data based self-supervised federated learning (FL) framework, named
SSL-FT-BT, to improve both the diagnostic accuracy and generalization of CAD
models. Specifically, the pseudo histopathological images are generated from
each center, which contains inherent and specific properties corresponding to
the real images in this center, but does not include the privacy information.
These pseudo images are then shared in the central server for self-supervised
learning (SSL). A multi-task SSL is then designed to fully learn both the
center-specific information and common inherent representation according to the
data characteristics. Moreover, a novel Barlow Twins based FL (FL-BT) algorithm
is proposed to improve the local training for the CAD model in each center by
conducting contrastive learning, which benefits the optimization of the global
model in the FL procedure. The experimental results on three public
histopathological image datasets indicate the effectiveness of the proposed
SSL-FL-BT on both diagnostic accuracy and generalization
Influence Of Novel Carbon Sources On Microstructure And Properties Of (Ti0.2Zr0.2Hf0.2Ta0.2Nb0.2)C High-entropy Carbide Ceramic
A set of (Ti0.2Zr0.2Hf0.2Ta0.2Nb0.2)C high-entropy carbide (HEC) ceramic samples were produced via spark plasma sintering (SPS) at a temperature of 1900 Ā°C utilizing synthesized carbide powders. The carbide powders were synthesized via carbothermal reduction and derived from various carbon sources including carbon black, carbon microspheres, flake graphite, and graphitic carbon spheres. The impact of the different carbon sources was evaluated, for the first time, on the HEC\u27s phase composition, microstructure, mechanical properties, and oxidation behavior. Results show that the HEC prepared using graphitic carbon spheres had a single-phase rock salt structure, with an average grain size of approximately 770 nm, which was smaller than that of HEC samples derived from the other carbon sources, due to its lower oxygen content, better dispersion, and higher chemical reactivity. Additionally, these HEC samples manufactured using graphitic carbon spheres exhibited 98.9% relative density, 20.39 GPa hardness, 4.5 Ā± 0.6 MPaĀ·m1/2 fracture toughness, and excellent oxidation resistance. Therefore, by optimizing the reactivity and dispersion of carbon sources, high-performance HEC ceramics can be created
Cold exposure promotes coronavirus infection by altering the gut microbiota and lipid metabolism to reduce host immunity
Cold exposure has been suggested to be advantageous for the spread and infection of the coronavirus, and the gut microbiota influences the severity of the infection by modulating host inflammatory and immune responses. However, it remains unclear whether the promotion of viral infection through cold exposure is linked to the gut microbiota
Construction of a Novel Infectious Clone of Recombinant Herpesvirus of Turkey Fc-126 Expressing VP2 of IBDV
The increased virulence of infectious bursal disease virus (IBDV) is a threat to the chicken industry. The construction of novel herpesvirus of turkey-vectored (HVT) vaccines expressing VP2 of virulent IBDV may be a promising vaccine candidate for controlling this serious disease in chickens. We generated a novel infectious clone of HVT Fc-126 by inserting mini-F sequences in lieu of the glycoprotein C (gC) gene. Based on this bacterial artificial chromosome (BAC), a VP2 expression cassette containing the pMCMV IE promoter and a VP2 sequence from the virulent IBDV NJ09 strain was inserted into the noncoding area between the UL55 and UL56 genes to generate the HVT vector VP2 recombinant, named HVT-VP2-09. The recovered vectored mutant HVT-VP2-09 exhibited higher titers (p = 0.0202 at 36 h) or similar growth kinetics to the parental virus HVT Fc-126 (p = 0.1181 at 48 h and p = 0.1296 at 64 h). The high reactivation ability and strong expression of VP2 by HVT-VP2-09 in chicken embryo fibroblasts (CEFs) were confirmed by indirect immunofluorescence (IFA) and Western blotting. The AGP antibodies against IBDV were detected beginning at 3 weeks post-inoculation (P.I.) of HVT-VP2-09 in 1-day-old SPF chickens. Seven of ten chickens immunized with HVT-VP2-09 were protected post-challenge (P.C.) with the virulent IBDV NJ09 strain. In contrast, all chickens in the challenge control group showed typical IBD lesions in bursals, and eight of ten died P.C. In this study, we demonstrated that (i) a novel HVT BAC with the whole genome of the Fc-126 strain was obtained with the insertion of mini-F sequences in lieu of the gC gene; (ii) HVT-VP2-09 harboring the VP2 expression cassette from virulent IBDV exhibited in vitro growth properties similar to those of the parental HVT virus in CEF cells; and (iii) HVT-VP2-09 can provide efficient protection against the IBDV NJ09 strain
A Novel Strategy of US3 Codon De-Optimization for Construction of an Attenuated Pseudorabies Virus against High Virulent Chinese Pseudorabies Virus Variant
In this study, we applied bacterial artificial chromosome (BAC) technology with PRVĪTK/gE/gI as the base material to replace the first, central, and terminal segments of the US3 gene with codon-deoptimized fragments via two-step Red-mediated recombination in E. coli GS1783 cells. The three constructed BACs were co-transfected with gI and part of gE fragments carrying homologous sequences (gI+gEā), respectively, in swine testicular cells. These three recombinant viruses with US3 codon de-optimization ((PRVĪTK&gE-US3deopā1, PRVĪTK&gE-US3deopā2, and PRVĪTK&gE-US3deopā3) were obtained and purified. These three recombinant viruses exhibited similar growth kinetics to the parental AH02LA strain, stably retained the deletion of TK and gE gene fragments, and stably inherited the recoded US3. Mice were inoculated intraperitoneally with the three recombinant viruses or control virus PRVĪTK&gEAH02 at a 107.0 TCID50 dose. Mice immunized with PRVĪTK&gE-US3deopā1 did not develop clinical signs and had a decreased virus load and attenuated pathological changes in the lungs and brain compared to the control group. Moreover, immunized mice were challenged with 100 LD50 of the AH02LA strain, and PRVĪTK&gE-US3deopā1 provided similar protection to that of the control virus PRVĪTK&gEAH02. Finally, PRVĪTK&gE-US3deopā1 was injected intramuscularly into 1-day-old PRV-negative piglets at a dose of 106.0 TCID50. Immunized piglets showed only slight temperature reactions and mild clinical signs. However, high levels of seroneutralizing antibody were produced at 14 and 21 days post-immunization. In addition, the immunization of PRVĪTK&gE-US3deopā1 at a dose of 105.0 TCID50 provided complete clinical protection and prevented virus shedding in piglets challenged by 106.5 TCID50 of the PRV AH02LA variant at 1 week post immunization. Together, these findings suggest that PRVĪTK&gE-US3deopā1 displays great potential as a vaccine candidate