Signature of the coexistence of ferromagnetism and superconductivity at KTaO3_3 heterointerfaces

The coexistence of superconductivity and ferromagnetism is a long-standing issue in the realm of unconventional superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism is challenging. Here, we report the experimental observation of long-range ferromagnetic order at the verge of two-dimensional superconductivity at KTaO$_3$ heterointerfaces. Remarkably, we observe in-plane magnetization hysteresis loop persisting up to room temperature with direct current superconducting quantum interference device measurements. Furthermore, first-principles calculations suggest that the observed robust ferromagnetism is attributed to the presence of oxygen vacancies that localize electrons in nearby Ta 5$d$ states. Our findings not only indicate KTaO$_3$ heterointerfaces as unconventional superconductors with time-reversal symmetry breaking, but also inject a new momentum to the study of the delicate interplay between superconductivity and magnetism boosted by strong spin-orbit coupling inherent to the heavy Ta in 5$d$ orbitals of KTaO$_3$ heterointerfaces.Comment: 7 pages, 3 figure

Quantum metallic state in the titanium sesquioxide heterointerface superconductor

The emergence of the quantum metallic state marked by a saturating finite electrical resistance in the zero-temperature limit in a variety of two-dimensional superconductors injects a new momentum to the realm of unconventional superconductivity. Despite much research efforts over last few decades, there is not yet a general consensus on the nature of this unexpected quantum metal. Here, we report the unique quantum metallic state within the hallmark of Bose-metal characterized by the saturated resistance and simultaneously vanished Hall resistance in the titanium sesquioxide heterointerface superconductor Ti$_2$O$_3$/GaN. Strikingly, the quantum bosonic metallic state proximate to the two-dimensional superconductivity-metal transition tuned by magnetic fields persists in the normal phase, suggesting that the existence of composite bosons formed by electron Cooper pairs survives even in the normal phase. Our work marks the observation of the preformed electron Cooper pairs in heterointerface superconductor and sheds new light on understanding the underlying pairing mechanism of unconventional superconductivity.Comment: 6 pages, 4 figure

A Review on Bioactivities of Tobacco Cembranoid Diterpenes

Cembranoids are carbocyclic diterpenes comprising four isoprene units and are natural products with a parent skeleton consisting of a 14-membered ring. They have gained wide interest in recent years and are a major hotspot in the research of natural product chemistry. Since 1962, various tobacco cembranoid diterpenes have been identified. This review systematically discusses and summarises the excellent antimicrobial, insecticidal, cytotoxic and neuroprotective activities of tobacco cembranoid diterpenes. These compounds show potential to be developed as botanical fungicides, cytotoxic drugs and drugs for the treatment of human immunodeficiency virus, Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative diseases. However, there are relatively few studies on the structure–activity relationship (SAR) of tobacco cembranoid diterpenes. Therefore, future studies should focus on their structural modification, SAR and biogenic relationships

Solanesol Biosynthesis in Plants

Solanesol is a non-cyclic terpene alcohol composed of nine isoprene units that mainly accumulates in solanaceous plants. Solanesol plays an important role in the interactions between plants and environmental factors such as pathogen infections and moderate-to-high temperatures. Additionally, it is a key intermediate for the pharmaceutical synthesis of ubiquinone-based drugs such as coenzyme Q10 and vitamin K2, and anti-cancer agent synergizers such as N-solanesyl-N,N′-bis(3,4-dimethoxybenzyl) ethylenediamine (SDB). In plants, solanesol is formed by the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway within plastids. Solanesol’s biosynthetic pathway involves the generation of C5 precursors, followed by the generation of direct precursors, and then the biosynthesis and modification of terpenoids; the first two stages of this pathway are well understood. Based on the current understanding of solanesol biosynthesis, we here review the key enzymes involved, including 1-deoxy-d-xylulose 5-phosphate synthase (DXS), 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), isopentenyl diphosphate isomerase (IPI), geranyl geranyl diphosphate synthase (GGPPS), and solanesyl diphosphate synthase (SPS), as well as their biological functions. Notably, studies on microbial heterologous expression and overexpression of key enzymatic genes in tobacco solanesol biosynthesis are of significant importance for medical uses of tobacco

bHLH Transcription Factor NtMYC2a Regulates Carbohydrate Metabolism during the Pollen Development of Tobacco (Nicotiana tabacum L. cv. TN90)

Basic helix-loop-helix (bHLH) transcription factor MYC2 regulates plant growth and development in many aspects through the jasmonic acid (JA) signaling pathway, while the role of MYC2 in plant carbohydrate metabolism has not been reported. Here, we generated NtMYC2a-overexpressing (NtMYC2a-OE) and RNA-interference-mediated knockdown (NtMYC2a-RI) transgenic plants of tobacco (Nicotiana tabacum L. cv. TN90) to investigate the role of NtMYC2a in carbohydrate metabolism and pollen development. Results showed that NtMYC2a regulates the starch accumulation and the starch-sugar conversion of floral organs, especially in pollen. The RT-qPCR analysis showed that the expression of starch-metabolic-related genes, AGPs, SS2 and BAM1, were regulated by NtMYC2a in the pollen grain, anther wall and ovary of tobacco plants. The process of pollen maturation was accelerated in NtMYC2a-OE plants and was delayed in NtMYC2a-RI plants, but the manipulation of NtMYC2a expression did not abolish the pollen fertility of the transgenic plants. Intriguingly, overexpression of NtMYC2a also enhanced the soluble carbohydrate accumulation in tobacco ovaries. Overall, our results demonstrated that the bHLH transcription factor NtMYC2a plays an important role in regulating the carbohydrate metabolism during pollen maturation in tobacco

Genome-Wide Analysis of Long Non-Coding RNAs in Potato and Their Potential Role in Tuber Sprouting Process

Sprouting is a key factor affecting the quality of potato tubers. The present study aimed to compare the differential expression of long non-coding RNAs (lncRNAs) in the apical meristem during the dormancy release and sprouting stages by using lncRNA sequencing. Microscopic observations and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed the changes in the morphology and expression of lncRNAs in potato tubers during sprouting. Meristematic cells of potato tuber apical buds divided continuously and exhibited vegetative cone bulging and vascularisation. In all, 3175 lncRNAs were identified from the apical buds of potato tubers, among which 383 lncRNAs were up-regulated and 340 were down-regulated during sprouting. The GO enrichment analysis revealed that sprouting mainly influenced the expression of lncRNAs related to the cellular components of potato apical buds (e.g., cytoplasm and organelles) and cellular metabolic processes. The KEGG enrichment analysis also showed significant enrichment of specific metabolic pathways. In addition, 386 differentially expressed lncRNAs during sprouting were identified as putative targets of 235 potato miRNAs. Quantitative real-time polymerase chain reaction results agreed with the sequencing data. Our study provides the first systematic study of numerous lncRNAs involved in the potato tuber sprouting process and lays the foundation for further studies to elucidate their precise functions

Chemical Basis of the Fungicidal Activity of Tobacco Extracts against Valsa mali

Under pressure from social criticism and an unclear future, tobacco researchers have begun to seek alternative uses for the product. Here, we present our study on isolating tobacco compounds with fungicidal activity, which could be used as plant-derived pesticides. Using Valsa mali as the target fungus, agar plate tests were conducted to evaluate the fungicidal activity of various tobacco extracts, including tobacco leaves extracts prepared with different solvents, extracts of different tobacco cultivars, and samples from different tobacco organs. Fungal growth morphology was used as the criterion to evaluate the fungicidal activity of tobacco extracts. Correlation analyses between the fungicidal activities and the chemical components of tobacco extracts indicated the major chemical constituents with fungicidal activity. Then, the active compounds were isolated and their effects on the ultra-microstructures of V. mali was analyzed using scanning- and transmission-electron microscopy. The results suggested that tobacco extracts prepared with solvents of weaker polarity had higher fungicidal activity, and the inhibitory activity of tobacco extracts against V. mali was also cultivar dependent. Furthermore, the fungicidal effects of tobacco flower extracts were higher than those of the leaf extracts. Chemical analysis indicated that cembranoids were the main fungicidal substances, which act by destroying the endometrial structure of the fungus. Tobacco cembranoids at 80 μg/mL could completely inhibit the growth of V. mali, with an EC50 value of 13.18 μg/mL. Our study therefore suggests that tobacco leaves and inflorescences are excellent plant resources for the biological control of V. mali

Imaging lattice switching with Talbot effect in reconfigurable non-Hermitian photonic graphene

International audienceBy taking advantage of the optical induction method, a non-Hermitian photonic graphene lattice is efficiently established inside an atomic vapor cell under the condition of electromagnetically induced transparency. This non-Hermitian structure is accomplished by simultaneously modulating both the real and imaginary components of the refractive index into honeycomb profiles. The transmitted probe field can either exhibit a hexagonal or honeycomb intensity profile when the degree of non-Hermiticity is effectively controlled by the ratio between imaginary and real indices. The experimental realization of such an instantaneously tunable complex honeycomb potential sets a new platform for future experimental exploration of non-Hermitian topological photonics. Also, we demonstrate the Talbot effect of the transmitted probe patterns. Such a self-imaging effect based on a non-Hermitian structure provides a promising route to potentially improve the related applications, such as an all-optical-controllable Talbot–Lau interferometer

Morphological Characteristics, Nutrients, and Bioactive Compounds of Zizania latifolia, and Health Benefits of Its Seeds

Zizania latifolia (tribe Oryzeae Dum., subfamily Oryzoideae Care, family Gramineae) is native to East Asian countries. The seeds of Z. latifolia (Chinese wild rice) have been consumed as a cereal in China for >3000 years. Z. latifolia forms swollen culms when infected with Ustilago esculenta, which is the second most-cultivated aquatic vegetable in China. The current review summarizes the nutrients and bioactive compounds of Z. latifolia, and health benefits of its seeds. The seeds of Z. latifolia contain proteins, minerals, vitamins, and bioactive compounds, the activities of which—for example, antioxidant activity—have been characterized. Various health benefits are associated with their consumption, such as alleviation of insulin resistance and lipotoxicity, and protection against cardiovascular disease. Chinese wild rice may be used to prevent and treat metabolic disease, such as diabetes, obesity, and cardiovascular diseases. Various compounds were isolated from the swollen culm, and aerial parts of Z. latifolia. The former suppresses osteoclast formation, inhibits growth of rat glioma cells, and may act as antioxidants and immunomodulators in drugs or foods. The latter exerts anti-fatigue, anti-inflammatory, and anti-allergic effects. Thus, Z. latifolia may be used to produce nutraceuticals and functional foods

Genome-Wide Analysis of the Growth-Regulating Factor Family in Peanut (Arachis hypogaea L.)

Growth-regulating factors (GRFs) are plant-specific transcription factors that perform important functions in plant growth and development. Herein, we identified and characterised 24 AhGRF genes in peanut (Arachis hypogaea). AhGRF family genes were divided into six classes with OLQ and WRC domains. Transcriptome expression profile showed that more AhGRF genes, such as AhGRF5a gene, were at higher expression during pod development in Arachis monticola than cultivated species, especially at the pod rapid-expansion stage. AhGRF5a and AhGRF5b genes expressed at higher levels in pods than roots, leaves and stems tissues, existing in the difference between Arachis monticola and H8107. Exogenous GA3 application can activate AhGRF5a and AhGRF5b genes and H8107 line showed more positive response than Arachis monticola species. These results imply that these two AhGRF genes may be active during the peanut pod development