The ovary is perhaps the most dynamic organ in the human body, only rivaled by the uterus. The molecular mechanisms that regulate follicular growth and regression, ensuring ovarian tissue homeostasis, remain elusive. We have performed single-cell RNA-sequencing using human adult ovaries to provide a map of the molecular signature of growing and regressing follicular populations. We have identified different types of granulosa and theca cells and detected local production of components of the complement system by (atretic) theca cells and stromal cells. We also have detected a mixture of adaptive and innate immune cells, as well as several types of endothelial and smooth muscle cells to aid the remodeling process. Our results highlight the relevance of mapping whole adult organs at the single-cell level and reflect ongoing efforts to map the human body. The association between complement system and follicular remodeling may provide key insights in reproductive biology and (in)fertility.

The current understanding of mammalian kidney development is largely based on mouse models. Recent landmark studies revealed pervasive differences in renal embryogenesis between mouse and human. The scarcity of detailed gene expression data in humans therefore hampers a thorough understanding of human kidney development and the possible developmental origin of kidney diseases. In this paper, we present a single-cell transcriptomics study of the human fetal kidney. We identified 22 cell types and a host of marker genes. Comparison of samples from different developmental ages revealed continuous gene expression changes in podocytes. To demonstrate the usefulness of our data set, we explored the heterogeneity of the nephrogenic niche, localized podocyte precursors, and confirmed disease-associated marker genes. With close to 18,000 renal cells from five different developmental ages, this study provides a rich resource for the elucidation of human kidney development, easily accessible through an interactive web application.

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Bacterial wilt is a devastating disease of tomato caused by soilborne pathogenic bacterium Ralstonia solanacearum. Previous studies found that silicon (Si) can increase tomato resistance against R. solanacearum, but the exact molecular mechanism remains unclear. RNA sequencing (RNA-Seq) technology was used to investigate the dynamic changes of root transcriptome profiles between Si-treated (+Si) and untreated (−Si) tomato plants at 1, 3, and 7 days post-inoculation with R. solanacearum. The contents of salicylic acid (SA), ethylene (ET), and jasmonic acid (JA) and the activity of defense-related enzymes in roots of tomato in different treatments were also determined. The burst of ET production in roots was delayed, and SA and JA contents were altered in Si treatment. The transcriptional response to R. solanacearum infection of the +Si plants was quicker than that of the untreated plants. The expression levels of differentially-expressed genes involved in pathogen-associated molecular pattern-triggered immunity (PTI), oxidation resistance, and water-deficit stress tolerance were upregulated in the Si-treated plants. Multiple hormone-related genes were differentially expressed in the Si-treated plants. Si-mediated resistance involves mechanisms other than SA- and JA/ET-mediated stress responses. We propose that Si-mediated tomato resistance to R. solanacearum is associated with activated PTI-related responses and enhanced disease resistance and tolerance via several signaling pathways. Such pathways are mediated by multiple hormones (e.g., SA, JA, ET, and auxin), leading to diminished adverse effects (e.g., senescence, water-deficit, salinity and oxidative stress) normally caused by R. solanacearum infection. This finding will provide an important basis to further characterize the role of Si in enhancing plant resistance against biotic stress.

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Electrocatalysis is critical to the performance displayed by sulfur cathodes. However, the constituent electrocatalysts and the sulfur reactants have vastly different molecular sizes, which ultimately restrict electrocatalysis efficiency and hamper device performance. Herein, the authors report that aggregates of cobalt single‐atom catalysts (SACs) attached to graphene via porphyrins can overcome the challenges associated with the catalyst/reactant size mismatch. Atomic‐resolution transmission electron microscopy and X‐ray absorption spectroscopy measurements show that the Co atoms present in the SAC aggregates exist as single atoms with spatially resolved dimensions that are commensurate the sulfur species found in sulfur cathodes and thus fully accessible to enable 100% atomic utilization efficiency in electrocatalysis. Density functional theory calculations demonstrate that the Co SAC aggregates can interact with the sulfur species in a synergistic manner that enhances the electrocatalytic effect and promote the performance of sulfur cathodes. For example, Li–S cells prepared from the Co SAC aggregates exhibit outstanding capacity retention (i.e., 505 mA h g–1 at 0.5 C after 600 cycles) and excellent rate capability (i.e., 648 mA h g−1 at 6 C). An ultrahigh area specific capacity of 12.52 mA h cm−2 is achieved at a high sulfur loading of 11.8 mg cm–2.

Active packaging film was developed by incorporating Lycium barbarum fruit extract (LFE) into chitosan. The effects of LFE on physicochemical properties of the chitosan/LFE films were evaluated. When the weight ratio of LFE to chitosan was increased from 0:1 to 1:1, DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity of the chitosan/LFE films increased near ten-folds and reached up to 35.8%; water vapour permeability of the chitosan/LFE films decreased 43.0% from 5.67 g m mm À2 day À1 kPa À1 , and water solubility decreased from 100% to 24.52% because of interactions between LFE and hydrophilic groups of chitosan confirmed by FTIR. However, the chitosan/LFE films became darker after LFE was incorporated. The pure chitosan film showed better tensile strength (23.19 MPa) and elongation at break (22.29%) than the chitosan/LFE films (15.52 MPa and 9.58% for the one with weight ratio of LFE to chitosan of 0.6:1).