Molecular regulatory mechanisms of staminate strobilus development and dehiscence in Torreya grandis.

Gymnosperms are mostly dioecious, and their staminate strobili undergo a longer developmental period than those of angiosperms. However, the underlying molecular mechanisms remain unclear. This study aimed to identify key genes and pathways involved in staminate strobilus development and dehiscence in Torreya grandis. Through weighted gene co-expression network analysis (WGCNA), we identified fast elongation-related genes enriched in carbon metabolism and auxin signal transduction, whereas dehiscence-related genes were abundant in alpha-linolenic acid metabolism and the phenylpropanoid pathway. Based on WGCNA, we also identified PHYTOCHROME-INTERACTING FACTOR4 (TgPIF4) as a potential regulator for fast elongation of staminate strobilus and 2 WRKY proteins (TgWRKY3 and TgWRKY31) as potential regulators for staminate strobilus dehiscence. Multiple protein-DNA interaction analyses showed that TgPIF4 directly activates the expression of TRANSPORT INHIBITOR RESPONSE2 (TgTIR2) and NADP-MALIC ENZYME (TgNADP-ME). Overexpression of TgPIF4 significantly promoted staminate strobilus elongation by elevating auxin signal transduction and pyruvate content. TgWRKY3 and TgWRKY31 bind to the promoters of the lignin biosynthesis gene PHENYLALANINE AMMONIA-LYASE (TgPAL) and jasmonic acid metabolism gene JASMONATE O-METHYLTRANSFERASE (TgJMT), respectively, and directly activate their transcription. Overexpression of TgWRKY3 and TgWRKY31 in the staminate strobilus led to early dehiscence, accompanied by increased lignin and methyl jasmonate levels, respectively. Collectively, our findings offer a perspective for understanding the growth of staminate strobili in gymnosperms.

Human umbilical cord mesenchymal stem cell-derived exosomes ameliorate renal fibrosis in diabetic nephropathy by targeting Hedgehog/SMO signaling.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease globally. Currently, there are no effective drugs for the treatment of DN. Although several studies have reported the therapeutic potential of mesenchymal stem cells, the underlying mechanisms remain largely unknown. Here, we report that both human umbilical cord MSCs (UC-MSCs) and UC-MSC-derived exosomes (UC-MSC-exo) attenuate kidney damage, and inhibit epithelial-mesenchymal transition (EMT) and renal fibrosis in streptozotocin-induced DN rats. Strikingly, the Hedgehog receptor, smoothened (SMO), was significantly upregulated in the kidney tissues of DN patients and rats, and positively correlated with EMT and renal fibrosis. UC-MSC and UC-MSC-exo treatment resulted in decrease of SMO expression. In vitro co-culture experiments revealed that UC-MSC-exo reduced EMT of tubular epithelial cells through inhibiting Hedgehog/SMO pathway. Collectively, UC-MSCs inhibit EMT and renal fibrosis by delivering exosomes and targeting Hedgehog/SMO signaling, suggesting that UC-MSCs and their exosomes are novel anti-fibrotic therapeutics for treating DN.

Ultrabright Xanthene Fluorescence Probe for Mitochondrial Super-Resolution Imaging.

Mitochondria are important organelles that provide energy for cellular physiological activities. Changes in their structures may indicate the occurrence of diseases, and the super-resolution imaging of mitochondria is of great significance. However, developing fluorescent probes for mitochondrial super-resolution visualization still remains challenging due to insufficient fluorescence brightness and poor stability. Herein, we rationally synthesized an ultrabright xanthene fluorescence probe Me-hNR for mitochondria-specific super-resolution imaging using structured illumination microscopy (SIM). The rigid structure of Me-hNR provided its ultrahigh fluorescence quantum yield of up to 0.92 and ultrahigh brightness of up to 16,000. Occupying the para-position of the O atom in the xanthene skeleton by utilizing the smallest methyl group ensured its excellent stability. The study of the photophysical process indicated that Me-hNR mainly emitted fluorescence via radiative decay, and nonradiative decay and inter-system crossing were rare due to the slow nonradiative decay rate and large energy gap (ΔEst = 0.55 eV). Owing to these excellent merits, Me-hNR can specifically light up mitochondria at ultralow concentrations down to 5 nM. The unprecedented spatial resolution for mitochondria with an fwhm of 174 nm was also achieved. Therefore, this ultrabright xanthene fluorescence probe has great potential in visualizing the structural changes of mitochondria and revealing the pathogenesis of related diseases using SIM.

Effects of calcium phosphate and phosphorus-dissolving bacteria on microbial structure and function during Torreya Grandis branch waste composting.

BACKGROUND BURKHOLDERIA: is a phosphorus solubilizing microorganism discovered in recent years, which can dissolve insoluble phosphorus compounds into soluble phosphorus. To investigate the effects of Burkholderia and calcium phosphate on the composting of Torreya grandis branches and leaves, as well as to explain the nutritional and metabolic markers related to the composting process. METHODS: In this study, we employed amplicon sequencing and untargeted metabolomics analysis to examine the interplay among phosphorus (P) components, microbial communities, and metabolites during T. grandis branch and leaf waste composting that underwent treatment with calcium phosphate and phosphate-solubilizing bacteria (Burkholderia). There were four composting treatments, 10% calcium phosphate (CaP) or 5 ml/kg (1 × 108/ml Burkholderia) microbial inoculum (WJP) or both (CaP + WJP), and the control group (CK). RESULTS: The results indicated that Burkholderia inoculation and calcium phosphate treatment affected the phosphorus composition, pH, EC, and nitrogen content. Furthermore, these treatments significantly affected the diversity and structure of bacterial and fungal communities, altering microbial and metabolite interactions. The differential metabolites associated with lipids and organic acids and derivatives treated with calcium phosphate treatment are twice as high as those treated with Burkholderia in both 21d and 42d. The results suggest that calcium phosphate treatment alters the formation of some biological macromolecules. CONCLUSION: Both Burkholderia inoculation and calcium phosphate treatment affected the phosphorus composition, nitrogen content and metabolites of T. grandis branch and leaf waste compost.These results extend our comprehension of the coupling of matter transformation and community succession in composting with the addition of calcium phosphate and phosphate-solubilizing bacteria.

Sucrose promotes cone enlargement via the TgNGA1-TgWRKY47-TgEXPA2 module in Torreya grandis.

Cone enlargement is a crucial process for seed production and reproduction in gymnosperms. Most of our knowledge of cone development is derived from observing anatomical structure during gametophyte development. Therefore, the exact molecular mechanism underlying cone enlargement after fertilization is poorly understood. Here, we demonstrate that sucrose promotes cone enlargement in Torreya grandis, a gymnosperm species with relatively low rates of cone enlargement, via the TgNGA1-TgWRKY47-TgEXPA2 pathway. Cell expansion plays a significant role in cone enlargement in T. grandis. 13C labeling and sucrose feeding experiments indicated that sucrose-induced changes in cell size and number contribute to cone enlargement in this species. RNA-sequencing analysis, transient overexpression in T. grandis cones, and stable overexpression in tomato (Solanum lycopersicum) suggested that the expansin gene TgEXPA2 positively regulates cell expansion in T. grandis cones. The WRKY transcription factor TgWRKY47 directly enhances TgEXPA2 expression by binding to its promoter. Additionally, the NGATHA transcription factor TgNGA1 directly interacts with TgWRKY47. This interaction suppresses the DNA-binding ability of TgWRKY47, thereby reducing its transcriptional activation on TgEXPA2 without affecting the transactivation ability of TgWRKY47. Our findings establish a link between sucrose and cone enlargement in T. grandis and elucidate the potential underlying molecular mechanism.

Transcription factors TgbHLH95 and TgbZIP44 cotarget terpene biosynthesis gene TgGPPS in Torreya grandis nuts.

Terpenes are volatile compounds responsible for aroma and the postharvest quality of commercially important xiangfei (Torreya grandis) nuts, and there is interest in understanding the regulation of their biosynthesis. Here, a transcriptomics analysis of xiangfei nuts after harvest identified 156 genes associated with the terpenoid metabolic pathway. A geranyl diphosphate (GPP) synthase (TgGPPS) involved in production of the monoterpene precursor GPP was targeted for functional characterization, and its transcript levels positively correlated with terpene levels. Furthermore, transient overexpression of TgGPPS in tobacco (Nicotiana tabacum) leaves or tomato (Solanum lycopersicum) fruit led to monoterpene accumulation. Analysis of differentially expressed transcription factors identified one basic helix-loop-helix protein (TgbHLH95) and one basic leucine zipper protein (TgbZIP44) as potential TgGPPS regulators. TgbHLH95 showed significant transactivation of the TgGPPS promoter, and its transient overexpression in tobacco leaves led to monoterpene accumulation, whereas TgbZIP44 directly bound to an ACGT-containing element in the TgGPPS promoter, as determined by yeast 1-hybrid test and electrophoretic mobility shift assay. Bimolecular fluorescence complementation, firefly luciferase complementation imaging, co-immunoprecipitation, and GST pull-down assays confirmed a direct protein-protein interaction between TgbHLH95 and TgbZIP44 in vivo and in vitro, and in combination these proteins induced the TgGPPS promoter up to 4.7-fold in transactivation assays. These results indicate that a TgbHLH95/TgbZIP44 complex activates the TgGPPS promoter and upregulates terpene biosynthesis in xiangfei nuts after harvest, thereby contributing to its aroma.

Temperature sum models in plant spring phenology studies: two commonly used methods have different fields of application.

In studies of plant spring phenology, temperature sum models are traditional tools. They are used to quantify plant development in terms of accumulation of temperature-dependent developmental units, such as Growing Degree Hours, GDHs. A key parameter in these models is the threshold (or base) temperature, Tthr, representing the lower thermal limit for the development to occur. The parameter can be either estimated when the model is fitted into the data or fixed a priori. Here we examine the limitations of both methods and identify fields of applications for each of them.

Genomics analysis of three phosphorus-dissolving bacteria isolated from Torreya grandis soil.

With the increasingly serious problem of phosphorus deficiency in the subtropical zone, chemical fertilizers are widely used. But it pollutes the environment. Phosphorus-solubilizing microorganisms (PSMs) are referred to as a new solution to this problem. We explored the phosphorus-dissolving characteristics of PSB strains isolated from the rhizosphere soil of Torreya grandis to provide a theoretical basis for selecting the strain for managing phosphorus deficiency in subtropical soils and also provides a more sufficient theoretical basis for the utilization of PSMs. From 84 strains, three strains exhibiting high phosphorus solubility and strong IAA producing capacity were selected through a series of experiments. The phosphate-solubilizing capacity of the three selected strains W1, W74, and W83 were 339.78 mg/L, 332.57 mg/L, and 358.61 mg/L, respectively. Furthermore, W1 showed the strongest IAA secreting capacity of 8.62 mg/L, followed by W74 (7.58 mg/L), and W83 (7.59 mg/L). Determination by metabolites, it was observed that these three strains dissolved phosphorus by secreting a large amount of lactic acid, aromatic acid, and succinic acid. The genome of these PSBs were sequenced and annotated in this study. Our results revealed that PSB primarily promotes their metabolic pathway, especially carbon metabolism, to secrete plenty organic acids for dissolving insoluble phosphorus.

Nutrient competition between female cones and young seeds in spring affects the physiological dropping and nut-setting rate in Torreya grandis.

Physiological seed drop is a recognized phenomenon in economic forest, caused by the abscission of developing seeds due to intergroup competition for resources. However, little is known about the resource allocation dynamics in species exhibiting a biennial fruiting cycle, where interactions occur not only among seeds of the same year but also between reproductive structures from consecutive years. In this study, we explored the dynamics of resource allocation in Torreya grandis, a nut crop with a prototypical two-year seed development pattern. We implemented thinning treatments of 0%, 30%, and 60% on female cones and/or immature seeds during the spring, targeting various stages of development both pre- and post-pollination. Our findings reveal a pronounced resource competition in Torreya, evidenced by a natural seed-setting rate of merely 9.4%. Contrary to expectations, seed thinning did not lead to an obvious increase in nut-setting rates, whereas a substantial increase to 20.5% was observed when female cones were thinned by 60% at 20 days before pollination. The cone thinning treatment appears to have influenced seed development through positive cytokinin and negative abscisic acid effects. This indicates that intergroup competition between female cones and nuts is a more significant factor in seed drop than inner nut competition, and there seems to be an interaction between the two groups. We demonstrate that, in Torreya with biennial seed development, it is the competition between female cones and immature seeds that is important. This insight expands our comprehension of the physiological mechanisms governing seed drop in biennial fruiting species and managing the reproductive organ load to optimize nutrient allocation.

Gardenia jasminoides Ellis. Polysaccharides Alleviated Cholestatic Liver Injury by Increasing the Production of Butyric Acid and FXR Activation.

Gardenia jasminoides Ellis. polysaccharide (GPS) can protect against cholestatic liver injury (CLI) by regulating nuclear farnesoid X receptor (FXR).However, the mechanism via which GPS mediates the FXR pathway remains unclear. The aim of this study was to investigate the mechanism. Firstly, an alpha-naphthylisothiocyanate-induced cholestatic mouse model was administered with GPS to evaluate its hepatoprotective effects. The metabolic pathways influenced by GPS in cholestatic mice were detected by serum metabolomics. The effect of GPS on bile acid (BA) homeostasis, FXR expression, and liver inflammation were investigated. Second, the intestinal bacteria metabolites affected by GPS in vivo and in vitro were determined. The activation of FXR by sodium butyrate (NaB) was measured. Finally, the effects of NaB on cholestatic mice were demonstrated. The main pathways influenced by GPS involved BA biosynthesis. GPS upregulated hepatic FXR expression, improved BA homeostasis, reduced F4/80+ and Ly6G+ positive areas in the liver, and inhibited liver inflammation in cholestatic mice. Butyric acid was the most notable intestinal bacterial metabolite following GPS intervention. NaB activated the transcriptional activity of FXR in vitro, upregulated hepatic FXR and its downstream efflux transporter expression, and ameliorated disordered BA homeostasis in CLI mice. NaB inhibited the toll-like receptor 4/nuclear factor (TLR4/NF-κB) pathway and reduced inflammation and CLI in mice. An FXR antagonist suppressed the effects. In conclusion, GPS increased butyric acid production, which can activate hepatic FXR, reverse BA homeostasis disorder, and inhibit the TLR4/NF-κB inflammatory pathway, exerting protective effects against CLI.

Genome-Wide Identification, Expression Analysis under Abiotic Stress and Co-Expression Analysis of MATE Gene Family in Torreya grandis.

The multidrug and toxin efflux (MATE) family participates in numerous biological processes and plays important roles in abiotic stress responses. However, information about the MATE family genes in Torreya grandis remains unclear. In this study, our genome-wide investigation identified ninety MATE genes in Torreya grandis, which were divided into five evolutionary clades. TgMATE family members are located on eleven chromosomes, and a total of thirty TgMATEs exist in tandem duplication. The promoter analysis showed that most TgMATEs contain the cis-regulatory elements associated with stress and hormonal responses. In addition, we discovered that most TgMATE genes responded to abiotic stresses (aluminum, drought, high temperatures, and low temperatures). Weighted correlation network analysis showed that 147 candidate transcription factor genes regulated the expression of 14 TgMATE genes, and it was verified through a double-luciferase assay. Overall, our findings offer valuable information for the characterization of the TgMATE gene mechanism in responding to abiotic stress and exhibit promising prospects for the stress tolerance breeding of Torreya grandis.

Gas Chromatography-Mass Spectrometry Metabolites and Transcriptome Profiling Reveal Molecular Mechanisms and Differences in Terpene Biosynthesis in Two Torrya grandis Cultivars during Postharvest Ripening.

Terpene aroma compounds are key quality attributes of postharvest Torreya grandis nuts, contributing to their commercial value. However, terpene biosynthesis and regulatory networks in different T. grandis cvs. are still poorly understood. Here, chief cvs. 'Xi Fei' and 'Xiangya Fei' were investigated for their differences in terpene biosynthesis and gene expression levels during postharvest ripening using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and transcriptomic datasets. A total of 28 and 22 aroma compounds were identified in 'Xi Fei' and 'Xiangya Fei', respectively. Interestingly, differences in aroma composition between the two cvs. were mostly attributed to D-limonene and α-pinene levels as key determinants in Torreya nuts' flavor. Further, transcriptome profiling, correlation analysis, and RT-qPCR annotated two novel genes, TgTPS1 in 'Xi Fei' and TgTPS2 in 'Xiangya Fei', involved in terpene biosynthesis. In addition, six transcription factors (TFs) with comparable expression patterns to TgTPS1 and four TFs to TgTPS2 were identified via correlation analysis of a volatile and transcriptome dataset to be involved in terpene biosynthesis. Our study provides novel insight into terpene biosynthesis and its regulation at the molecular level in T. grandis nut and presents a valuable reference for metabolic engineering and aroma improvement in this less explored nut.

Polarity-Sensitive Probe for Two-Photon Fluorescence Lifetime Imaging of Lipid Droplets In Vitro and In Vivo.

Lipid droplets (LDs) are crucial organelles used to store lipids and participate in lipid metabolism in cells. The abnormal aggregation and polarity change of LDs are associated with the occurrence of diseases, such as steatosis. Herein, the polarity-sensitive probe TBPCPP with a donor-acceptor-π-acceptor (D-A-π-A) structure was designed and synthesized. The TBPCPP has a large Stokes shift (∼220 nm), excellent photostability, high LD targeting, and considerable two-photon absorption (TPA) cross-section (∼226 GM), enabling deep two-photon imaging (∼360 µm). In addition, the fluorescence lifetime of TBPCPP decreases linearly with increasing solvent polarity. Therefore, with the assistance of two-photon fluorescence lifetime imaging microscopy (TP-FLIM), TBPCPP has successfully achieved not only the visualization of polarity changes caused by LD accumulation in HepG-2 cells but also lipid-specific imaging and visualization of different polarities in lipid-rich regions in zebrafish for the first time. Furthermore, TP-FLIM revealed that the polarity gradually decreases during steatosis in HepG-2 cells, which provided new insights into the diagnosis of steatosis.

Advances on delta 5-unsaturated-polymethylene-interrupted fatty acids: Resources, biosynthesis, and benefits.

Though the knowledge on delta 5-unsaturated-polymethylene-interrupted fatty acids (Δ5-UPIFAs) is being updated, the issue of their integration still exists within the field. Thus, this review systematically summarizes the sources, biosynthesis and metabolism, analytical methods, preparation, and health-promoting roles of Δ5-UPIFAs. In plants, the content of Δ5-UPIFAs is higher, which is an ideal source. In animals, although the content of Δ5-UPIFAs is not high, there are many species, which is the possible source of some special Δ5-UPIFAs. At present, although the extraction of Δ5-UPIFAs is mainly from plants, the fermentation by organisms, especially for genetically modified microorganisms engineering maybe be a substitue of pepration of Δ5-UPIFAs. Δ5-UPIFAs have been proved to possess multi-beneficial effects, such as lipid lowering, anti-inflammation and so on, so it has a certain potential application value. However, related knowledge of the underlying molecular mechanisms regarding Δ5-UPIFAs limited, and how Δ5-UPIFAs work is not clear. Further clinical and human studies about Δ5-UPIFAs are also needed. Studies on tapping new resources, developing structured lipide rich in Δ5-UPIFA and enhancing delivery were quite deficient. This review emphasizes the further directions on Δ5-UPIFAs with scientific suggestions to pay more attention to the applications of Δ5-UPIFAs in food, pharmaceutical and cosmetic industries.

Integrated Metabolomics, Transcriptome and Functional Analysis Reveal Key Genes Are Involved in Tree Age-Induced Amino Acid Accumulation in Torreya grandis Nuts.

Torreya grandis is native Chinese tree species of economic significance, renowned for its long lifespan and the rich nutritional value of its nuts. In this study, we analyzed the morphological characteristics, metabolites, associated gene expressions, and regulatory mechanism in nuts from young (10 years old) and old (1000 years old) T. grandis trees. We observed that the length, width, and weight of nuts from older trees were considerably greater than those from younger trees. Metabolomic analysis revealed that the concentrations of 18 amino acids and derivatives (including histidine and serine) in nuts from older trees were markedly higher than those in nuts from younger trees. Transcriptome and metabolomic correlation analysis identified 16 genes, including TgPK (pyruvate kinase), TgGAPDH (glyceraldehyde 3-phosphate dehydrogenase), and others, which exhibit higher expression levels in older trees compared to younger trees, as confirmed by qRT-PCR. These genes are associated with the biosynthesis of histidine, glutamic acid, tryptophan, and serine. Transient expression of TgPK in tobacco led to increased pyruvate kinase activity and amino acid content (histidine, tryptophan, and serine). Additionally, dual-luciferase assays and yeast one-hybrid results demonstrated that TgWRKY21 positively regulates TgPK expression by directly binding to the TgPK promoter. These findings not only demonstrate the nutritional differences between nuts from young and old trees but also offer fresh insights into the development of nutritional sources and functional components based on nuts from old trees, enriching our understanding of the potential benefits of utilizing nuts from older trees.

Two Polarity-Sensitive Fluorescent Probes Based on Curcumin Analogs for Visualizing Polarity Changes in Lipid Droplets.

As a class of highly dynamic organelles, lipid droplets (LDs) are involved in numerous physiological functions, and the changes in polarity of LDs are closely related to a variety of diseases. In this work, we developed two polarity-sensitive fluorescent probes (CC-CH and CC-Cl) based on curcumin analogs. CC-CH and CC-Cl with a donor-acceptor-donor (D-A-D) structure exhibited the property of intramolecular charge transfer (ICT); thus, their fluorescence emissions were significantly attenuated with increasing ambient polarity. Cell experiments indicated that CC-CH and CC-Cl showed excellent photostability, a low cytotoxicity, and a superior targeting ability regarding LDs. After treatment with oleic acid (OA) and methyl-ß-cyclodextrin (M-ß-CD), the polarity changes of LDs in living cells could be visualized by using CC-CH and CC-Cl. In addition, CC-CH and CC-Cl could monitor polarity changes of LDs in different pathological processes, including inflammatory responses, nutrient deprivation, and H2O2-induced oxidative stress. Therefore, CC-CH and CC-Cl are promising potential fluorescent probes for tracking intracellular LD polarity changes.

The salt-activated CBF1/CBF2/CBF3-GALS1 module fine-tunes galactan-induced salt hypersensitivity in Arabidopsis.

Plant growth and development are significantly hampered in saline environments, limiting agricultural productivity. Thus, it is crucial to unravel the mechanism underlying plant responses to salt stress. ß-1,4-Galactan (galactan), which forms the side chains of pectic rhamnogalacturonan I, enhances plant sensitivity to high-salt stress. Galactan is synthesized by GALACTAN SYNTHASE1 (GALS1). We previously showed that NaCl relieves the direct suppression of GALS1 transcription by the transcription factors BPC1 and BPC2 to induce the excess accumulation of galactan in Arabidopsis (Arabidopsis thaliana). However, how plants adapt to this unfavorable environment remains unclear. Here, we determined that the transcription factors CBF1, CBF2, and CBF3 directly interact with the GALS1 promoter and repress its expression, leading to reduced galactan accumulation and enhanced salt tolerance. Salt stress enhances the binding of CBF1/CBF2/CBF3 to the GALS1 promoter by inducing CBF1/CBF2/CBF3 transcription and accumulation. Genetic analysis suggested that CBF1/CBF2/CBF3 function upstream of GALS1 to modulate salt-induced galactan biosynthesis and the salt response. CBF1/CBF2/CBF3 and BPC1/BPC2 function in parallel to regulate GALS1 expression, thereby modulating the salt response. Our results reveal a mechanism in which salt-activated CBF1/CBF2/CBF3 inhibit BPC1/BPC2-regulated GALS1 expression to alleviate galactan-induced salt hypersensitivity, providing an activation/deactivation fine-tune mechanism for dynamic regulation of GALS1 expression under salt stress in Arabidopsis.

New Xanthene Dyes with NIR-II Emission Beyond 1200 nm for Efficient Tumor Angiography and Photothermal Therapy.

Fluorescence (FL) bioimaging in the second near-infrared window (NIR-II, 1000-1700 nm) provides improved imaging quality and high resolution for diagnosis of deep-seated tumors. However, integrating FL bioimaging and photothermal therapy (PTT) in a single photoactive molecule exhibits a great challenge because a dramatic increase of PTT in the NIR-II window benefitting from the nonradiative decay will sacrifice the fluorescence brightness that is unfavorable for FL bioimaging. Therefore, balancing the radiative decay and nonradiative decay is an effective and rational design strategy. Herein, four NIR-II xanthene dyes (CL1-CL4) are synthesized with maximal emission beyond 1200 nm under 1064 nm excitation. CL4 exhibits the largest fluorescence quantum yield and a significant fluorescence enhancement after complexation with fetal bovine serum (FBS). As-prepared CL4/FBS has a maximal emission of 1235 nm and a high photothermal conversion efficiency of 36% under 1064 nm excitation. Bright and refined tumor vessels with a fine resolution of 0.23 mm can be clearly distinguished by CL4/FBS. In vivo studies show that a balanced utilization of fluorescence and photothermy in the NIR-II window is successfully achieved with superior biocompatibility. This efficient strategy provides promising avenue for precise theranostics of deep tumors.

Synthesis of graphdiyne on a copper substrate via a self-coupling reaction.

A new strategy is proposed to prepare graphdiyne via the self-coupling reaction of hexakis(bromoethynyl)benzene (hBEP) with alkynyl bromide groups. Prominently, the reaction can proceed moderately in 12 h at room temperature. The as-synthesized film displays a porous structure, excellent chemical characteristics, and an admirable catalytic performance for the hydrogen/oxygen evolution reaction (HER/OER).

Design and synthesis of yolk-shell Fe2O3/N-doped carbon nanospindles with rich oxygen vacancies for robust lithium storage.

Ferric oxide (Fe2O3) is an attractive anode material for lithium-ion batteries (LIBs) with a high theoretical capacity of 1005 mA h g-1. However, its practical application is greatly restrained by the rapid capacity fading caused by the large volume expansion upon lithiation. To address this issue, we have designed and synthesized a unique yolk-shell Fe2O3/N-doped carbon hybrid structure (YS-Fe2O3@NC) with rich oxygen vacancies for robust lithium storage. The obtained results show that YS-Fe2O3@NC delivers a high reversible capacity of 578 mA h g-1 after 300 cycles at a current density of 5 A g-1, about 11 times that (53.7 mA h g-1) of pristine Fe2O3. Furthermore, a high specific capacity of 300.5 mA h g-1 even at 10 A g-1 is achieved. The high reversible capacities, excellent rate capability and cycle stability of YS-Fe2O3@NC might be attributed to the elaborate yolk-shell nanoarchitecture. Moreover, electron percolation and a local built-in electric field induced by oxygen vacancies in the Fe2O3 matrix could also enhance the kinetics of Li+ insertion/deinsertion.