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An essential aspect of the design of a pebble bed high-temperature gas-cooled reactor (HTGR) is the consideration of heat transfer. A particle-scale heat transfer model was developed based on the previous GPU-DEM numerical model. This model includes the heat conduction of the particles in contact, the radiative heat transfer among particles, and unidirectional convection heat transfer in the flow field. The comparison of the predicted results with the results of the TF-PBEC experiment demonstrates the accuracy of the conduction and radiation modules within the current model. Based on the current model and the porous media model, a numerical study of the natural convection heat transfer in the High-Temperature gas-cooled Reactor-Pebble-bed Module (HTR-PM) after reactor shutdown is performed. This paper systematically introduces the model design, pebble bed generation, flow field calculation, and heat transfer simulation. The results indicate that natural convection contributes to removing residual heat in the reactor core, and a higher pressure leads to better convection heat transfer. At extremely low Reynolds numbers (Re < 10), convection heat transfer is comparable to conduction and radiation, while for pressurized pebble beds (Re = 50–500), convection heat transfer dominates. Furthermore, the influence of different models used to calculate the Nusselt number of the results is compared and analyzed. For most cases, the differences in the temperature distribution of the pebble bed obtained from the different correlations are minor. However, the impact of porosity on the local Nusselt number cannot be ignored in the extremely low Reynolds numbers flows. Overall, the particle-scale heat transfer model can provide more effective reference information for the design and construction of an HTGR. • A GPU-DEM-based particle-scale heat transfer model is proposed for heat transfer in HTGRs. • The Heat conduction, radiation, and gas-particle convection in the whole field are simulated. • The entire core size of HTR-PM is simulated to analyze the pebble flow and temperature. • The effects of Re and porosity on Nu are explored, and different correlations are analyzed. [ABSTRACT FROM AUTHOR]

Based on the discrete element method (DEM) and GPU parallel computing, a particle heat transfer model is developed to simulate the heat transfer in a pebble bed of the high-temperature gas-cooled reactor (HTGR). The model is implemented based on a previously developed GPU-DEM program by our team and uses the mesh-based neighbor searching algorithm for the heat transfer calculation. This model couples the conduction and radiative heat transfer between the pebbles and incorporates neural networks and empirical fittings to calculate the radiation view factors, which can improve computational efficiency. The effective thermal conductivity of different models and experimental data are used to verify the accuracy of the model, and the influence of different radiation heat transfer models on the results is also compared. The results show that the effective thermal conductivity derived from the current model is comparable to the classical models at different temperatures, and the numerical simulation results based on the current model are in good agreement with the corresponding experimental data. Additionally, the model achieves a single-core speedup ratio of 126–395 times with GPU acceleration, significantly enhancing computational efficiency. In conclusion, the current model has been effectively verified for accuracy and computational efficiency, and it demonstrates great potential in dealing with large-scale pebble flow and heat transfer challenges in HTGRs. • A Voronoi-tessellation-free new heat transfer model is proposed for pebble beds. • View factors are calculated by neural networks to couple conduction and radiation. • GPU parallel computing is employed at a speedup ratio of 126–395 times of CPU. • An alternate-read-write method and unified Memory Access technology are used. • The model accuracy is validated and discussed by comparing it with experiments. [ABSTRACT FROM AUTHOR]

CRISPR-based base editors (BEs) are powerful tools for precise nucleotide substitution in a wide range of organisms, but spatiotemporal control of base editing remains a daunting challenge. Herein, we develop a photoactivatable base editor (Mag-ABE) for spatiotemporally controlled genome editing in vivo for the first time. The base editing activity of Mag-ABE can be activated by blue light for spatiotemporal regulation of both EGFP reporter gene and various endogenous genes editing. Meanwhile, the Mag-ABE prefers to edit A4 and A5 positions rather than to edit A6 position, showing the potential to decrease bystander editing of traditional adenine base editors. After integration with upconversion nanoparticles as a light transducer, the Mag-ABE is further applied for near-infrared (NIR) light-activated base editing of liver in transgenic reporter mice successfully. This study opens a promising way to improve the operability, safety, and precision of base editing. [Display omitted] [ABSTRACT FROM AUTHOR]

As an ingredient of vaccines, adjuvants are indispensable for enhancing and directly inducing robust and extensive adaptive immune responses associated with vaccine antigens. In this study, we initially determined that a new molecular immunopotentiator, ophiopogonin D (OP-D), enhanced the antibody response to antigen. Because OP-D has certain disadvantages, including poor solubility, we next encapsulated OP-D in a nanoemulsion adjuvant (nanoemulsion-encapsulated OP-D, NOD) using low-energy emulsification methods. The NOD thus produced was small, with an average size of 76.45 nm, and exhibited good distribution (PdI value 0.16), significantly increasing the solubility of OP-D. Furthermore, NOD exhibited reduced cellular toxicity and acute toxicity. Our results showed that a fusion antigen of MRSA (HlaH 35L IsdB 348-465 ) formulated with NOD significantly improved humoral and cellular immune responses compared to those observed in the antigen/OP-D and antigen/AlPO 4 groups. Compared with antigen/OP-D, the antigen formulated with NOD more effectively promoted antigen uptake by dendritic cells (DCs) and the activation of antigen-presenting cells (APCs). Moreover, the NOD-formulated antigen had ideal protective efficacy in a MRSA sepsis model by inducing more potent antibody responses and a Th1/Th17-biased CD4 + T cell immune response. Therefore, these results suggest that NOD is a promising and robust adjuvant platform for a MRSA vaccine. Statement of Significance We first identified a new powerful immunopotentiator, Ophiopogonin D, among dozens of natural products and then used nanotechnology to construct a highly efficient and low toxic adjuvant system (NOD). Our approach intersects natural medicinal chemistry, nanomaterials and immunology, revealing that a strong adjuvant activity of this adjuvant system was verified in vitro and in vivo, and the application of MRSA subunit vaccine model for survival experiments achieved a 100% protection rate. This research illustrate that NOD is a promising and robust adjuvant platform for subunit vaccines. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are a kind of small single-strand RNA molecules with lengths of 18–25 nt, which do not encode any proteins. They play an essential role in gene expression regulation by binding to their target genes, leading to translational repression or transcript degradation. In this study, 23 miRNAs were predicted from five cyprinidae fishes by using a bioinformatics-based gene search based on blasting ESTs and GSS in NCBI, of which 21 miRNA genes have not been previously reported. To prove their validity, five of the computationally predicted miRNAs were verified by RTPCR, their transcripts were successfully detected, and, 46 potential target genes for these miRNAs were predicted, most target genes encode transcription factors, they are involved in signal transduction, metabolism and development processes. [ABSTRACT FROM AUTHOR]

Diverse oxygen generation strategies have been developed to overcome hypoxia in tumors for enhancing the therapeutic efficacy, but inevitably suffering from tedious synthesis process of oxygen generators in vitro before in vivo administration. Herein, we show direct injection of commercially and clinically used KMnO 4 into solid tumors enables in situ formation of MnO 2 as an oxygen depot for cascade oxidation damage and enhanced photodynamic therapy. KMnO 4 can damage tumor tissues by oxidation and generate MnO 2 , and subsequent intravenous injection of Ce6 allows MnO 2 -triggered hypoxia-modulated photodynamic therapy of tumors. Excellent cascade tumor suppression effect is realized both in vitro and in vivo based on the KMnO 4 –Ce6 system without the need of synthesis. The proposed strategy lays down a novel way with unprecedented superiors of no need of synthesis process and ultra-facile administration procedure for tumor hypoxia-modulated cascade therapy. Intratumoral injection of KMnO 4 can not only damage tumor cells by oxidation, but also generate MnO 2 as a minimalist O 2 generator, and subsequently intravenous injection of Ce6 allows hypoxia-modulated photodynamic therapy of tumors. The proposed strategy lays down a new way with unprecedented superiors of avoiding the synthesis process and ultra-facile administration procedure for tumor hypoxia-modulated cascade therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are a family of single-stranded RNA molecules about 22 nt in length, which can regulate protein-coding gene expression in various organisms by post-transcriptional repression of messenger. In this research, the potential miRNAs and their target genes were analyzed and predicted by computational methods from the EST and GSS databases of eleven fish species, 43 potential miRNAs were identified, they belong to 38 miRNA families, some miRNAs are highly conserved in animal kingdom, the predicted target genes are involved in development, signal transduction, response to environmental stress and pathogen invasion. Taken together, our data suggest that there are a plentiful of miRNAs in these eleven fish species, these miRNAs may play some important roles by regulating their target genes, and the data provide important information for further functional studies. [ABSTRACT FROM AUTHOR]

Abstract: Porous Fe3O4-decorated graphene (GN–Fe3O4) composites with different microstructures were successfully synthesized by a modified two-step method. The microstructure and morphology were confirmed by X-ray diffraction (XRD), transmission electron microscopy and scanning electron microscopy. XRD studies show that the products consist of highly crystallized Fe3O4 but disorderedly stacked GN sheets. Electron microscopy images reveal that Fe3O4 nanoparticles with different sizes and microstructures are uniformly coated on both sides of GN sheets, without large vacancies or apparent aggregation. Electromagnetic wave absorption properties of epoxy containing 30 wt.% GN–Fe3O4 composites were investigated at room temperature in the frequency range of 0.5–18GHz. In particular, the porous, flower-like Fe3O4-decorated GN sample exhibits an enhanced dielectric loss due to the porous microstructure of Fe3O4. The multiple absorbing mechanisms attribute to the improved impedance matching which indicates the as-prepared porous GN–Fe3O4 composites could be a potential candidate for lightweight electromagnetic wave absorption materials. [Copyright &y& Elsevier]

Benefitting from transformation optics, the design of thermal harvesting devices by manipulating heat flux has aroused considerable interest owing to its potential application in heat storage and the fabrication of highly efficient and reliable solar cells and thermal collectors. However, studies on harvesting performance under different conditions achieved by the use of different design parameters are lacking. In this study, we focus on forecasting the harvesting performances of 2D thermal concentrating schemes with variational design parameters, including the ratios of conductivities and radii, wedge angles, and temperature differences. In order to evaluate the multi-parametric harvesting performance, an expression of efficient harvesting entropy was proposed based on the entropy generation distributions of thermal harvesting schemes. Response surface methodology (RSM) was employed to achieve the regression model of efficient harvesting entropy under different conditions. The accuracy of the forecast was verified by analysis of variance (ANOVA) and five confirmation tests. Moreover, the effects of interaction influences on efficient harvesting entropy of design parameters were described by 3D response surface. In general, this study indicates that a harvesting scheme with a higher ratio of conductivities and a smaller wedge angle and ratio of radii under a specified temperature gradient can provide a better concentrating performance. With the theoretical forecast of the harvesting performance, a satisfactory thermal harvesting device can be built under homologous conditions. [ABSTRACT FROM AUTHOR]

Thermal cloaks have been widely studied and experimented with. However, discussions on cloaking performance based on different design parameters effects are lacking. In this paper, we focus on predicting the cloaking performances of 2D thermal cloak schemes with different design parameters such as layer number, thickness, temperature difference, and relative thermal conductivity. The concept of response entropy, which is based on entropy generation analysis and is used to characterize the cloaking performance, is proposed. A regression model is established to predict the response entropy of the variational design parameters using response surface method (RSM). Five confirmation tests are conducted to verify the accuracy of the prediction. The relationship between the response entropy and the interaction effects of the design parameters are described with the help of 3D response surfaces using analysis of variance (ANOVA). In conclusion, we propose that a core-shell cloaking scheme with modest parametric values of 1–18 layers, a thickness of 1–5 mm, a small relative thermal conductivity, and large temperature difference can provide a better cloaking performance. This paper presents a theoretical prediction of the cloaking performance and provides suggestions on fabricating better thermal cloaks under different parameters. [ABSTRACT FROM AUTHOR]

Because there is an urgent need to develop antibacterial therapies other than antibiotics, research has increasingly focused on the high-temperature-requirement protein A (HtrA) family proteases, which have both serine protease and chaperone activities. The research progresses of the role of HtrA family proteases in the pathogenesis of bacterial infections are summarized, and the pros and cons of exploiting HtrA inhibitors in antibacterial drug development are proposed. A search of PubMed was performed to identify relevant studies. HtrA is essential for bacteria to survive in harsh environments, based on the degradation and refolding of misfolded proteins. Moreover, HtrA family protease can lyse the epithelial cell barrier to promote invasion and can also act as or assist virulence factors to enhance pathogenicity. On the other hand, HtrA secreted by certain bacteria can also affect intra- and interspecies biofilm formation (the mechanism of its promotion or inhibition has not yet been proven). Overall, in view of the role of the HtrA family in promoting bacterial pathogenicity, effective HtrA inhibitors may be an exciting direction for drug development. Therefore, the research progress regarding HtrA inhibitors are summarized and the risks of their application are discussed. This review will be useful both for investigators involved in the HtrA field as well as those wishing to acquire a basic understanding of the role and potential implementations of HtrA. [ABSTRACT FROM AUTHOR]

• Network analysis identified adaptive differences of Archaea& Bacteria in hot springs. • Internal competitions among bacterial species are more prevalent than among archaea. • Archaea and Bacteria can form their own guilds and occupy different niches. • pH (acidity) seems to play an important role in shaping niche differentiations. • Temperature influences species compositions more significantly than on abundances. It has been nearly a half-century long since the recognition of Archaea as one of the three kingdoms in the tree of life, but the comparative studies on their ecological adaptations with bacteria in the hot spring environment have been relatively few. We present the first few network analyses of the hot-spring microbiome with 165 hot-spring microbiome samples taken globally by Sharp et al (2014) (with the temperature and pH ranged 7.5°C-99°C and 1.8-9.0, respectively), offering an ideal dataset for investigating the structure and functional interactions in the hot-spring microbiome via network analysis. Here we aim to identify the ecologically adaptive differences between Archaea and Bacteria and discover: (i) Competitions as represented by negative correlations seem to be extremely rare among Archaea species; in contrast, the competitions among Bacteria species are much more common. (ii) Archaea and Bacteria can form their own guilds and occupy their own niches, and pH seems to play an important role in niche differentiations. (iii) The abundances of most Bacteria and Archaea are not correlated to the temperature. Bacteria have slightly more species that are thermo-phobic and no Archaea are thermo-phobic. The temperature may have far more significant influences on species compositions than on species abundance. In other words, most ' resident ' species can prosper in a wide range of temperatures but some ' nonresidents ' may encounter difficulties to survive. Theoretically, this is consistent with the classic biogeography dogma of microbes—they may reach everywhere, but environment selects who can stay. [ABSTRACT FROM AUTHOR]

The human papillomavirus (HPV), a common virus that infects the reproductive tract, may lead to malignant changes within the infection area in certain cases and is directly associated with such cancers as cervical cancer, anal cancer, and vaginal cancer. Identification of novel HPV infection related genes can lead to a better understanding of the specific signal pathways and cellular processes related to HPV infection, providing information for the development of more efficient therapies. In this study, several novel HPV infection related genes were predicted by a computation method based on the known genes involved in HPV infection from HPVbase. This method applied the algorithm of random walk with restart (RWR) to a protein-protein interaction (PPI) network. The candidate genes were further filtered by the permutation and association tests. These steps eliminated genes occupying special positions in the PPI network and selected key genes with strong associations to known HPV infection related genes based on the interaction confidence and functional similarity obtained from published databases, such as STRING, gene ontology (GO) terms and KEGG pathways. Our study identified 104 novel HPV infection related genes, a number of which were confirmed to relate to the infection processes and complications of HPV infection, as reported in the literature. These results demonstrate the reliability of our method in identifying HPV infection related genes. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang. [ABSTRACT FROM AUTHOR]