Search

Phase change heat storage presents a promising solution to address challenges related to new energy intermittency and waste heat recovery. However, for it to function as an effective energy hub, heat storage becomes crucial. Among the available options, the direct contact heat accumulator stands out due to its simple structure, substantial heat transfer area, and minimal heat transfer resistance, making it a favorable choice for enhancing energy storage rates. Although a great deal of research has been done on phase change materials and heat accumulators over the years, a systematic review of direct‐contact heat accumulators is lacking. This article reviews the related research on direct contact heat storage, aiming to summarize the research work on direct contact phase change heat storage systems. Various phase change materials (PCMs) for direct contact systems are analyzed, and the study of PCM melting crystallization behavior, heat transfer coefficients and system performance in direct contact systems is summarized, as well as the improvement methods for direct contact vessels and PCMs. It provides a useful reference for future research on direct‐contact heat storage systems. [ABSTRACT FROM AUTHOR]

Reductive activation of carbon dioxide (CO2) has drawn increasing attention as an effective and convenient method to unlock this stable molecule, especially via transition metal-catalyzed reactions. Taking the [TaC4O8]+ ion–molecule complex formed in the laser ablation source as a representative, the reactivity of the tantalum metal cation towards CO2 molecules is explored using infrared photodissociation spectroscopy combined with quantum chemical calculations. The strong absorption in the carbonyl stretching region provides solid evidence for the insertion reactions into C＝O bonds by the tantalum cation. Two inserted oxocarbonyl products are identified based on the great agreement between the experimental results and simulated infrared spectra of energetically low-lying structures in the singlet and triplet states. The pivotal role of two-state reactivity in driving CO2 activation among three different spin states is rationalized by potential energy surface analysis. Our conclusion provides valuable insight into the intrinsic mechanisms of CO2 activation by the tantalum metal cation, highlighting the affinity of tantalum for C＝O bond insertion in addition to typical "end-on" binding configurations. [ABSTRACT FROM AUTHOR]

Within catalyst inks, the agglomeration of carbon-supported Pt nanoparticles (Pt/C NPs) stands out as a primary destabilizing factor. This study simulates the agglomeration process of particles under varying ionic strengths (ISs), employing the Brownian motion of Pt/C NPs and inter-particle forces. The energy barriers (EBs) within particles govern particle interactions, subsequently translating into the adhesive efficiency of particle collisions (α). By modulating the ISs in Ink-P (IS = 0.00182), Ink-01 (IS = 0.01), and Ink-001 (IS = 0.001), the Zeta potential and EBs are diminished, thereby increasing α. Structural parameters of agglomerates during the agglomeration process, such as fractal dimension (df) and porosity, are computationally assessed using Matlab. The simulated df for Ink-P, Ink-001, and Ink-01 are 1.82, 1.62, and 1.54, respectively, while the experimentally measured df are 1.92–1.95, 1.67–1.7, and 1.56–1.59, confirming the effectiveness of the simulation method. High α led to isotropic growth of agglomerates, resulting in higher df. Increased IS causes compression of the electric double layer and higher α , ultimately leading to rapid destabilization of the ink. This method not only enhances comprehension of nanoscale particle agglomeration, explaining variations in ink stability and agglomerate structures, but also broadens its applicability to diverse nanoparticle dispersion systems. [Display omitted] • A Brownian dynamics model was proposed to describe the aggregation of catalyst. • The effect of ionic strength on the agglomeration of catalyst was elucidated. • Higher ionic strength leads to poorer stability of the catalyst ink. • The fractal dimension of agglomerates was confirmed by simulation and experiment. [ABSTRACT FROM AUTHOR]

Non-directional rafting of γ' phases in high generation nickel-based single crystal superalloys happens when the alloys are thermally exposed at high temperatures, but so far the reason remains unclear. The microstructures and internal stress fields of a 4th generation single crystal superalloy during thermal exposure at 1100 ℃ and 950 ℃ are investigated using transmission electron microscopy and finite element analysis. It is found that the non-directional rafting of γ' phases occurs after 1100 ℃/200 h and 950 ℃/500 h thermal exposures. The γ' phases are mainly rodlike shape in the space after thermal exposures and a small quantity of γ' rafts exist as well. The elastic strain energy gradient in γ matrix caused by the inhomogeneity of matrix channel width in the alloy is most likely the driving force for the non-directional rafting. Additionally, dislocations are observed only after the thermal exposure process at 1100 ℃. The effect of dislocations on non-directional rafting during thermal exposure is discussed in detail in the paper. • TEM and finite element analysis are used to study non-directional rafting of γ'. • γ' phases are mainly rodlike spatially after thermal exposure at high temperature. • It is found that dislocations are unnecessary for the non-directional rafting. • Elastic strain energy is larger in narrower γ matrix channel at high temperature. • Elastic strain energy gradient in matrix probably causes non-directional rafting. [ABSTRACT FROM AUTHOR]

Cracks are a common defect in the catalyst layers (CLs) of proton exchange membrane fuel cells (PEMFCs), deteriorating their performance. This study proposes benzoic acid as a cracking inhibitor in the catalyst ink. The additive strengthens the network of catalyst particles by promoting attractive interaction within them. Molecular dynamics simulations demonstrate that the inhibitor facilitates the desorption of ionomer from the Pt/carbon surface, weakening the repulsion force within catalyst particles. Rheology experiments indicate that the addition of benzoic acid transforms the catalyst ink from a sol-like to a gel-like, improving its viscosity and storage modulus. The stronger attractive interactions within the inhibitor-added ink impart anti-cracking ability, preventing stress release during the drying process. Furthermore, optical microscopy reveals a significant decrease in both the crack area and the maximum length of cracks in the CL after incorporating the inhibitor. Specifically, the crack area decreases from 13% to 2%, while the maximum crack length decreases from nearly 400 μm to 150 μm. Single cell tests show that the inhibitor-added sample exhibits a higher peak power density of 0.893 W/cm2 compared to the standard sample's 0.873 W/cm2. Overall, this study presents an effective method for manufacturing high-quality CLs in PEMFCs, ensuring improved performance. • Benzoic acid is employed to improve the anti-cracking ability of catalyst layers. • Internal states of catalyst inks are studied by a molecular dynamic simulation. • Benzoic acid promotes the desorption of ionomer from surface of catalyst. • Strong attractive interactions within ink prevent cracking of wet film. • Evolution processes of wet films are observed by optimal microscopy. [ABSTRACT FROM AUTHOR]

Premise: Theories of plant–herbivore interactions hold that seedlings are more vulnerable to herbivory in warmer and more stable climates at lower elevations. Hypotheses of plant apparency, resource concentration, and resource availability have been proposed to explain variability in leaf herbivory. However, seasonal differences in the effects of these hypotheses on leaf herbivory on seedlings remain unclear. Methods: We evaluated the three herbivory hypotheses by comparing the percentage and frequency of leaf herbivory in understory broadleaf seedlings in a subtropical forest in May (spring) and October (autumn) along an elevational gradient (290–1370 m a.s.l.). In total, we measured 2890 leaves across 696 seedlings belonging to 95 species and used beta regressions to test the effects of plant apparency (e.g., leaf area, seedling height), resource concentration (e.g., plant species diversity), and resource availability (e.g., canopy openness, soil available N and P) on leaf herbivory. Results: Seedlings exhibited unimodal patterns of leaf herbivory along elevation, with drivers of leaf herbivory varying by the month. Variation in the frequency of leaf herbivory was best explained by the resource concentration hypothesis (e.g., plant species diversity) in both months, and herbivory was lower on seedlings in sites with higher plant diversity. Plant apparency hypothesis (e.g., leaf area, seedling height) was weakly supported only in spring, and the evidence for resource availability hypothesis (e.g., canopy openness, soil nutrients) was mixed. Conclusions: This study supports the resource concentration hypothesis and reveals the importance of seasonal difference on understanding leaf herbivory patterns and the drivers of plant diversity in subtropical forests. [ABSTRACT FROM AUTHOR]

Species range size is a central topic in macroecology, biogeography and conservation biology. Species age has been frequently regarded as a contributor to range size in previous studies on range size, but this has rarely been specifically examined. Using global data from four living terrestrial vertebrate classes (birds, mammals, reptiles and amphibians) as a case study, we examine how species range size might be related to species age at a global scale. We found statistically significant positive, albeit weak, species age–range size relationships for all four species groups. However, although the age–range relationships were positive, species with young ages had very different range sizes (both large and small), and those with very old ages always had small ranges. The observed age–range relationships were more complex than expected. The weak, rather than strong, species age–range relationships could be because our data set included all living species with different stages of their life spans (durations) that are either expanding or fluctuating or contracting, which would necessarily have minimized or cancelled species age–range relationship when all species in a group are considered collectively. Our findings shed new light on temporal dimension and macroecological correlates of species ranges. [ABSTRACT FROM AUTHOR]

Background: The immature and suppressed immune response makes transplanted children a special susceptible group to Parvovirus B19 (PVB19). However, the clinical features of transplanted children with PVB19 infection haven't been comprehensively described. Methods: We searched the medical records of all the transplant recipients who attended the Children's Hospital of Fudan University from 1 Oct 2020 to 31 May 2023, and reviewed the medical literature for PVB19 infection cases among transplanted children. Results: A total of 10 cases of PVB19 infection were identified in 201 transplanted children at our hospital, and the medical records of each of these cases were shown. Also, we retrieved 40 cases of PVB19 infection among transplanted children from the literature, thus summarizing a total of 50 unique cases of PVB19 infection. The median time to the first positive PVB19 DNA detection was 14 weeks post-transplantation. PVB19 IgM and IgG were detected in merely 26% and 24% of the children, respectively. The incidence of graft loss/dysfunction was as high as 36%. Hematopoietic stem cell transplant (HSCT) recipients showed higher PVB19 load, lower HGB level, greater platelet damage, lower PVB19 IgM/IgG positive rates, and more graft dysfunction than solid-organ transplant (SOT) recipients, indicating a more incompetent immune system. Conclusions: Compared with the published data of transplanted adults, transplanted children displayed distinct clinical features upon PVB19 infection, including lower PVB19 IgM/IgG positive rates, more graft dysfunction, and broader damage on hematopoietic cell lines, which was even more prominent in HSCT recipients, thus should be of greater concern. [ABSTRACT FROM AUTHOR]

Molecular diffusion is critical for enhanced oil recovery (EOR) in shale oil reservoirs with complex fracture networks. Understanding the influence of fractures on diffusive mass transfer is crucial for predicting oil recovery and remaining oil distribution. Diffusive mass transfer between fractures and matrix is critical in comprehensively and effectively simulating molecular diffusion. Resolution of matrix cells significantly affects diffusion accuracy at the fracture–matrix interface. Low resolution results in multiple fractures in the same matrix cell, leading to decreased precision in calculating mass transfer by conventional methods. To address this, a novel multiphase and multicomponent model is proposed. The new model integrating the consideration of fracture spacing modifies molecular diffusion transmissibility between fracture and matrix in an embedded discrete fracture model. The discretization employs the two-point flux approximation in the finite-volume method. Validation compares the coarser mesh to the finest grid as a reliable reference. Results show the proposed model accurately captures diffusive mass transfer in a coarser mesh. Modified models study molecular diffusion's effects on EOR in shale oil reservoirs with complex fracture networks by CO2 huff and puff. Results indicate that increasing injection rates cannot improve oil recovery under extremely low porosity and permeability. Molecular diffusion facilitates CO2 penetration into the formation. This expands the swept CO2 volume and increases both volume expansion and formation energy. In addition, the light and heavy components of the crude oil are diffused into the fractures and eventually produced, which reduces gas production in the case of diffusion. [ABSTRACT FROM AUTHOR]

OVATE family proteins (OFPs) are a kind of plant-specific transcription factor, which play important roles in the growth and development of plants. Here, we performed a genome-wide investigation of the OFP gene family members in the wild diploid strawberry (Fragaria vesca, 2n = 14), and analyzed their physical and chemical properties, gene structure, phylogeny, expression patterns, and the subcellular localizations of these genes. Fourteen OFP genes from F.vesca were identified. Collinearity analysis showed ten pairs of collinearity between F. vesca and Arabidopsis. Phylogenetic analysis divided FvOFP genes into five different clades. The expression patterns of the FvOFP genes assayed in different tissues of F. vesca by Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) showed that FvOFP1, FvOFP11, FvOFP12, and FvOFP14 were highly expressed in achene and their expression was further verified in the fruits at different developmental stages. Additionally, the subcellular localizations of FvOFP1, FvOFP11, FvOFP12, and FvOFP14 were preliminarily analyzed in tobacco leaves. The results showed clear fluorescent signals in the nucleus. Our results provided a comprehensive understanding of the potential function of FvOFP genes in strawberries. [ABSTRACT FROM AUTHOR]

Calcium (Ca2+) is a versatile intracellular second messenger that regulates several signaling pathways involved in growth, development, stress tolerance, and immune response in plants. Autoinhibited Ca2+-ATPases (ACAs) play an important role in the regulation of cellular Ca2+ homeostasis. Here, we systematically analyzed the putative OsACA family members in rice, and according to the phylogenetic tree of OsACAs, OsACA9 was clustered into a separated branch in which its homologous gene in Arabidopsis thaliana was reported to be involved in defense response. When the OsACA9 gene was knocked out by CRISPR/Cas9, significant accumulation of reactive oxygen species (ROS) was detected in the mutant lines. Meanwhile, the OsACA9 knock out lines showed enhanced disease resistance to both rice bacterial blight (BB) and bacterial leaf streak (BLS). In addition, compared to the wild-type (WT), the mutant lines displayed an early leaf senescence phenotype, and the agronomy traits of their plant height, panicle length, and grain yield were significantly decreased. Transcriptome analysis by RNA-Seq showed that the differentially expressed genes (DEGs) between WT and the Osaca9 mutant were mainly enriched in basal immune pathways and antibacterial metabolite synthesis pathways. Among them, multiple genes related to rice disease resistance, receptor-like cytoplasmic kinases (RLCKs) and cell wall-associated kinases (WAKs) genes were upregulated. Our results suggest that the Ca2+-ATPase OsACA9 may trigger oxidative burst in response to various pathogens and synergically regulate disease resistance and leaf senescence in rice. [ABSTRACT FROM AUTHOR]

Age-related hearing loss (ARHL) is a common neurodegenerative disease. Its molecular mechanisms have not been fully elucidated. In the present study, we obtained differential mRNA expression in the cochlea of 2-month-old miR-29a +/+ mice and miR-29a −/− mice by RNA-seq. Gene ontology (GO) analysis was used to identify molecular functions associated with hearing in miR-29a −/− mice, including being actin binding (GO: 0003779) and immune processes. We focused on the intersection of differential genes, miR-29a target genes and the sensory perception of sound (GO:0007605) genes, with six mRNA at this intersection, and we selected Col1a1 as our target gene. We validated Col1a1 as the direct target of miR-29a by molecular and cellular experiments. Total 6 pathways involved in Col1a1 were identified by through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. We selected the focal adhesion pathway as our target pathway based. Their expression levels in miR-29a −/− mice were verified by qRT-PCR and Western blot. Compared with miR-29a +/+ mice, the expression levels of Col1a1 , Itga4 , Itga2 , Itgb3 , Itgb7 , Pik3r3 and Ptk2 were different in miR-29a −/− mice. Immunofluorescence was used to locate genes in the cochlea. Col1a1 , Itga4 and Itgb3 were differentially expressed in the basilar membranes and stria vascularis and spiral ganglion neurons compared to miR-29a +/+ mice. Pik3r3 and Ptk2 were differentially expressed in the basilar membranes and stria vascularis, but not at the s spiral ganglion neurons compared to miR-29a +/+ mice. Our results show that when miR-29a is knocked out, the Col1a1 mediates the focal adhesion pathway may affect the hearing of miR-29a −/− mice. These findings may provide a new direction for effective treatment of age-related hearing loss. • Age-related hearing loss miR-29a mouse model by RNA-seq analysis. • MiR-29a deletion leads to up-regulation of Col1a1 expression, which results in decreased hearing in mice. • Col1a1 is affecting hearing through the focal adhesion pathway. [ABSTRACT FROM AUTHOR]

For point clusters, the conflict and crowding of map symbols is an inevitable problem during the transition from large to small scales. The cartographic generalization involved in this problem as a spatial decision-making process is usually related to the analysis of spatial context, the choice of abstraction operators, and the judgment of the resulting data quality. The rules summarized by traditional generalization methods usually require manual setting of conditions or thresholds and sometimes encounter special cases that make it difficult to directly match certain rules or integrate different rules together. An alternative method is using a data-driven strategy under AI technology background to simulate cartographer behaviors through typical sample training, such as deep learning. The integration of cartography domain knowledge and deep learning is a better choice to settle generalization decisions. This study uses a combination of domain knowledge and a data-driven approach to introduce graph neural networks into point cluster generalization. First, we construct a virtual graph structure of point clusters using Delaunay triangulation, secondly, we extract spatial features, contextual features, and attributes of each point separately, and then propose a generalization model based on the TAGCN network. Finally, this model is trained with the manually generalized sample to realize the automatic point cluster generalization. The results demonstrate that the proposed model is valid and efficient for point cluster generalization and that this algorithm can better maintain various characteristics of the point cluster in both the local area and the overall map compared to other methods. [ABSTRACT FROM AUTHOR]

Neoadjuvant immunotherapy represents promising strategy in the treatment of esophageal squamous cell carcinoma (ESCC). However, the mechanisms underlying its impact on treatment sensitivity or resistance remain a subject of controversy. In this study, we conducted single-cell RNA and T/B cell receptor (scTCR/scBCR) sequencing of CD45+ immune cells on samples from 10 patients who received neoadjuvant immunotherapy and chemotherapy. We also validated our findings using multiplexed immunofluorescence and analyzed bulk RNA-seq from other cohorts in public database. By integrating analysis of 87357 CD45+ cells, we found GZMK + effector memory T cells (Tem) were relatively enriched and CXCL13+ exhausted T cells (Tex) and regulator T cells (Treg) decreased among responders, indicating a persistent anti-tumor memory process. Additionally, the enhanced presence of BCR expansion and somatic hypermutation process within TNFRSF13B + memory B cells (Bmem) suggested their roles in antigen presentation. This was further corroborated by the evidence of the T-B co-stimulation pattern and CXCL13-CXCR5 axis. The complexity of myeloid cell heterogeneity was also particularly pronounced. The elevated expression of S100A7 in ESCC, as detected by bulk RNA-seq, was associated with an exhausted and immunosuppressive tumor microenvironment. In summary, this study has unveiled a potential regulatory network among immune cells and the clonal dynamics of their functions, and the mechanisms of exhaustion and memory conversion between GZMK + Tem and TNFRSF13B + Bmem from antigen presentation and co-stimulation perspectives during neoadjuvant PD-1 blockade treatment in ESCC. • By integrating analysis of 87357 CD45+ cells, we defined CD8+ CXCL13+ exhausted T cells (Tex) were enriched and clonal expanded in the non-responsive patients and CD4+ LAIR2+Treg were in activated states and highly plastic with various clonal sharing, which pointed out an exhausted and immunosuppressive environment in non-responsive patient following PD-1 blockade treatment. While, GZMK + effector memory T cells (Tem) were relatively enriched in responders, which suggested a memory lasting anti-tumor process with the stem-like ab + and FCRL4+ memory B (Bmem) with more differentiated states and the BCR expansion phenomenon were observed in responders. The class-switch recombination (CSR) and somatic hypermutation (SHM) process were also enriched in TNFRSF13B + Bmem implying its mature state as antigen-presenting (APC) roles. Furthermore, T-B crosstalk process via CD28 − CD86 co-stimulation pattern and CXCL13-CXCR5 chemokines axis was validated using cellphoneDB algorithm and multiplex immunofluorescence (mIF) method. We also extracted a TNFRSF13B signature to predict response and OS benefits to immune checkpoint blockade in different cohorts to underscore their clinical relevance. • And the heterogeneity of myeloid cells was quite complex. According to pan-cancer results, we also validated FOLR2+ tissue-resident macrophage in our cohort showed a correlation with increment of Tem clusters, suggesting its APC roles. On the contrary, CCL3L1+ Neutrophils tended to a pro-tumoral phenotype with immunosuppressive and neutrophil extracellular traps (NETs) features. • While the elevated S100A7 in our ESCC cohort revealed by bulk RNA-seq relating to an exhaustion and immunosuppressive TME in upstream pathway may explain the inherent ICB resistance mechanism. [ABSTRACT FROM AUTHOR]

This paper presents an efficient inverse design method of arrayed waveguide grating (AWG) based on BPNN-PSO. Five important structural parameters of AWG are selected as inputs, and the spectral responses of three output channels are used as outputs. A forward network is trained, and the prediction accuracy of the network is improved by optimizing the number of hidden layer neurons. By combining the forward network with the traditional particle swarm optimization (PSO) algorithm, a series of structure designs targeting the desired performance can be generated. This method significantly improves the efficiency and accuracy of the PSO algorithm by introducing neural networks, making it suitable for efficient inverse design and multi-structure analysis of AWG. • Combining BPNN and PSO for AWG inverse design. • Training the forward network to replace the electromagnetic simulation process significantly reduces design time. • The design requirements for AWG allow for both spectral response and desired performance. • This method enables the multi-solution design of AWG according to the desired performance. [ABSTRACT FROM AUTHOR]