Transcriptome disclosure of hormones inducing stigma exsertion in Nicotiana tabacum by corolla shortening.

BACKGROUND: Stigma exsertion is an essential agricultural trait that can promote cross-pollination to improve hybrid seed production efficiency. However, the molecular mechanism controlling stigma exsertion remains unknown. RESULTS: In this study, the Nicotiana tabacum cv. K326 and its two homonuclear-heteroplasmic lines, MSK326 (male-sterile) and MSK326SE (male-sterile and stigma exserted), were used to investigate the mechanism of tobacco stigma exsertion. A comparison of the flowers between the three lines showed that the stigma exsertion of MSK326SE was mainly due to corolla shortening. Therefore, the corollas of the three lines were sampled and presented for RNA-seq analysis, which found 338 candidate genes that may cause corolla shortening. These genes were equally expressed in K326 and MSK326, but differentially expressed in MSK326SE. Among these 338 genes, 15 were involved in hormone synthesis or signal transduction pathways. Consistently, the content of auxin, dihydrozeatin, gibberellin, and jasmonic acid was significantly decreased in the MSK326SE corolla, whereas abscisic acid levels were significantly increased. Additionally, seven genes involved in cell division, cell cycle, or cell expansion were identified. Protein-protein interaction network analysis identified 45 nodes and 79 protein interactions, and the largest module contained 20 nodes and 52 protein interactions, mainly involved in the hormone signal transduction and pathogen defensive pathways. Furthermore, a putative hub gene coding a serine/threonine-protein kinase was identified for the network. CONCLUSIONS: Our results suggest that hormones may play a key role in regulating tobacco stigma exsertion induced by corolla shortening.

Adversarial network for multi-input image restoration under strong turbulence.

Turbulence generated by random ups and downs in the refractive index of the atmosphere produces varying degrees of distortion and blurring of images in the camera. Traditional methods ignore the effect of strong turbulence on the image. This paper proposes a deep neural network to enhance image clarity under strong turbulence to handle this problem. This network is divided into two sub-networks, the generator and the discriminator, whose functions are to mitigate the effects of turbulence on the image and to determine the authenticity of the recovered image. After extensive experiments, it is proven that the present network plays a role in mitigating the image degradation problem caused by atmospheric turbulence.

PGC-1α participates in tumor chemoresistance by regulating glucose metabolism and mitochondrial function.

Chemotherapy resistance is the main reason for the failure of cancer treatment. The mechanism of drug resistance is complex and diverse. In recent years, the role of glucose metabolism and mitochondrial function in cancer resistance has gathered considerable interest. The increase in metabolic plasticity of cancer cells' mitochondria and adaptive changes to the mitochondrial function are some of the mechanisms through which cancer cells resist chemotherapy. As a key molecule regulating the mitochondrial function and glucose metabolism, PGC-1α plays an indispensable role in cancer progression. However, the role of PGC-1α in chemotherapy resistance remains controversial. Here, we discuss the role of PGC-1α in glucose metabolism and mitochondrial function and present a comprehensive overview of PGC-1α in chemotherapy resistance.

Mesoporous Iron Family Element (Fe, Co, Ni) Molybdenum Disulfide/Carbon Nanohybrids for High-Performance Supercapacitors.

As the demand for fuel continues to increase, the development of energy devices with excellent performance is crucial. Supercapacitors (SCs) are attracting attention for their advantages of high specific energy and a long cycle life. At present, the development of high-performance electrode materials is the main point for research and development of SCs. Transition metal sulfides have the advantages of a large interlayer space and high theoretical capacity, making them promising electrode materials. Herein, we reported a series of ultrathin mesoporous iron family element (Fe, Co, Ni) molybdenum disulfide (MxMo1-xS2/C, M = Fe, Co, and Ni) by a template method. The original monolayer mesoporous structure of MoS2/C was maintained, and accumulation and agglomeration of MoS2/C were avoided. Based on our investigations, the best performance was that of CoxMo1-xS2/C nanohybrids. Furthermore, the concentrations of Co and Mo ions were modulated to obtain the best performance, in which Mo and Co ions were released at 1:1, 1:2, and 1:3 ratios and they were named CoxMo1-xS2/C-1, CoxMo1-xS2/C-2, and CoxMo1-xS2/C-3, respectively. Overall, these materials represent a significant improvement and show promise as high-performance SC electrode materials due to their enhanced capacitance and stability. At a current density of 0.5 A g-1, CoxMo1-xS2/C-2 has the optimal specific capacitance of 184 F g-1. CoxMo1-xS2/C-2 as an SC electrode exhibited better reversible capacity and cycling stability than MoS2/C, which is an improvement over MoS2/C regarding reversible capacity and cycling stability.

Central neck lymph node metastasis in oral squamous cell carcinoma at the floor of mouth.

BACKGROUND: Our goal was to analyze the incidence of level VI metastasis in previously untreated oral squamous cell carcinoma (SCC) patients and their clinicopathological and prognostic characteristics. METHODS: Oral SCC patients with level VI metastasis were retrospectively enrolled, and their demographic and pathologic features as well as their survival data were descriptively analyzed. RESULTS: A total of 13 cases from 1875 patients were included, all patients had SCC at the floor of mouth (SCCFOM). Eight (61.5%) patients had a pT4 tumor, and all patients had a pathological N3 neck with multiple positive lymph nodes. Adverse pathologic features were present in 100% of the patients. The size of the metastatic foci in level VI ranged from 2.6 cm to 4.5 cm with a mean value of 3.2 cm, and 5 patients showed a soft tissue deposit with no lymph node component. Recurrence occurred in all patients, and 11 patients died of uncontrolled cancer within 5 years after surgery. CONCLUSION: Level VI metastasis in primary oral SCCFOM is rare, and its prognosis is poor.

A Distributed Image Compression Scheme for Energy Harvesting Wireless Multimedia Sensor Networks.

As an emerging technology, edge computing will enable traditional sensor networks to be effective and motivate a series of new applications. Meanwhile, limited battery power directly affects the performance and survival time of sensor networks. As an extension application for traditional sensor networks, the energy consumption of Wireless Multimedia Sensor Networks (WMSNs) is more prominent. For the image compression and transmission in WMSNs, consider using solar energy as the replenishment of node energy; a distributed image compression scheme based on solar energy harvesting is proposed. Two level clustering management is adopted. The camera node-normal node cluster enables camera nodes to gather and send collected raw images to the corresponding normal nodes for compression, and the normal node cluster enables the normal nodes to send the compressed images to the corresponding cluster head node. The re-clustering and dynamic adjustment methods for normal nodes are proposed to adjust adaptively the operation mode in the working chain. Simulation results show that the proposed distributed image compression scheme can effectively balance the energy consumption of the network. Compared with the existing image transmission schemes, the proposed scheme can transmit more and higher quality images and ensure the survival of the network.

Double Switch Biodegradable Porous Hollow Trinickel Monophosphide Nanospheres for Multimodal Imaging Guided Photothermal Therapy.

Due to the limitation of inorganic nanomaterials in present clinical applications induced by their inherent nonbiodegradability and latent long-term side effects, we successfully prepared double switch degradable and clearable trinickel monophosphide porous hollow nanospheres (NiP PHNPs) modified with bovine serum albumin (BSA). Attributed to their acidic and oxidative double switch degradation capacities, NiP PHNPs can be effectively excreted from mice without long-term toxicity. Moreover, because of the paramagnetic and high molar extinction coefficient property resulting from the strong absorption in the second near-infrared light (NIR II) biowindow, NiP PHNPs have potential to be used for photoacoustic imaging (PAI) and T1-weighted magnetic resonance imaging (MRI) guided photothermal ablation of tumors in the NIR II biowindow. Specifically, it is interesting that the hollow structure and acidic degradation property enable NiP PHNPs to act as intelligent drug carriers with an on-demand release ability. These findings highlight the great potential of NiP PHNPs in the cancer theranostics field and inspire us to further broaden the bioapplications of transition metal phosphides.

Expression, purification, and in vitro characterization of kinase domain of NtGCN2 from tobacco.

General control nonderepressible 2 (GCN2) can phosphorylate the α subunit of eukaryotic initiation factor eIF2 (eukaryotic translation initiation factor 2) to down-regulateprotein synthesis in response to various biotic and abiotic stresses. However, the kinase activity of plant GCN2 has not been well-characterized in vitro. In this study, the kinase domain of Nicotiana tabacum GCN2 (NtGCN2) was inserted into the pET15b vector for prokaryotic expressionin Escherichia coli BL21-CodonPlus-(DE3)-RIPL after induction by 0.5 mmol L-1 IPTG for 13 h at 16 °C. The soluble protein was collected and purified by Ni2+-NTA agarose column, anion exchange, and molecular sieve, and the purified proteinwas used for kinase assays and the preparation of a polyclonal antibody. Enzyme-linked immunosorbent assay results showed that the titer of the antiserum was 1:520K. Western blot analysis showed that the prepared antibody reacted with GCN2 in tobacco. Additionally, the kinase activity of NtGCN2 was characterized by using recombinant NteIF2α protein as a substrate in vitro. The results showed that NtGCN2 phosphorylated NteIF2α in vitro, with the level of phosphorylation positively correlated with the NtGCN2 concentration and reaction time. Our study has prepared a specific antibody, and proves NtGCN2 can phosphorylate NteIF2α in vitro, which lays a foundation for further study of the function and interaction network of NtGCN2.

Carotenoid Cleavage Dioxygenases: Identification, Expression, and Evolutionary Analysis of This Gene Family in Tobacco.

Carotenoid cleavage dioxygenases (CCDs) selectively catalyze carotenoids, forming smaller apocarotenoids that are essential for the synthesis of apocarotenoid flavor, aroma volatiles, and phytohormone ABA/SLs, as well as responses to abiotic stresses. Here, 19, 11, and 10 CCD genes were identified in Nicotiana tabacum, Nicotiana tomentosiformis, and Nicotiana sylvestris, respectively. For this family, we systematically analyzed phylogeny, gene structure, conserved motifs, gene duplications, cis-elements, subcellular and chromosomal localization, miRNA-target sites, expression patterns with different treatments, and molecular evolution. CCD genes were classified into two subfamilies and nine groups. Gene structures, motifs, and tertiary structures showed similarities within the same groups. Subcellular localization analysis predicted that CCD family genes are cytoplasmic and plastid-localized, which was confirmed experimentally. Evolutionary analysis showed that purifying selection dominated the evolution of these genes. Meanwhile, seven positive sites were identified on the ancestor branch of the tobacco CCD subfamily. Cis-regulatory elements of the CCD promoters were mainly involved in light-responsiveness, hormone treatment, and physiological stress. Different CCD family genes were predominantly expressed separately in roots, flowers, seeds, and leaves and exhibited divergent expression patterns with different hormones (ABA, MeJA, IAA, SA) and abiotic (drought, cold, heat) stresses. This study provides a comprehensive overview of the NtCCD gene family and a foundation for future functional characterization of individual genes.

One-Dimensional Fe2 P Acts as a Fenton Agent in Response to NIR†II Light and Ultrasound for Deep Tumor Synergetic Theranostics.

The stringent reaction conditions for an effective Fenton reaction (pH range of 3-4) hinders its application in cancer therapy. Therefore, how to improve the efficiency of the Fenton reaction in a tumor site has been the main obstacle in chemodynamic therapy (CDT). Herein, we report biocompatible one-dimensional (1D) ferrous phosphide nanorods (FP NRs) with ultrasound (US)- and photothermal (PT)-enhanced Fenton properties and excellent photothermal conversion efficiency (56.6 %) in the NIR II window, showing synergistic therapeutic properties. Additionally, the high photothermal conversion efficiency and excellent traverse relaxivity (277.79 mm-1 s-1 ) of the FP NRs means they are excellent photoacoustic imaging (PAI) and magnetic resonance imaging (MRI) agents. This is the first report on exploiting the response of metallic phosphides to NIR II laser (1064 nm) and ultrasound to improve the CDT effect with a high therapeutic effect and PA/MR imaging.

Metabolic Flux Engineering of Cembratrien-ol Production in Both the Glandular Trichome and Leaf Mesophyll in Nicotiana tabacum.

Cembratrien-ol synthase (CBTS) catalyzes the first step in cembranoid biosynthesis, producing cembratrien-ols in plant trichomes. In our previous study, microarray transcriptomes between leaves with trichomes and leaves without trichomes showed that an NtCBTS2 gene was expressed exclusively and abundantly in trichomes. Here, two NtCBTS2 isogenes (NtCBTS2a and NtCBTS2b), derived from a diploid genome donor, Nicotiana sylvestris, were identified from N. tabacum. Both genes were expressed primarily in trichomes, with relatively decreased transcription in flowers and stems, and faint expression in roots, and no expression was detected in leaves lacking trichomes. To demonstrate the feasibility of producing natural product cembratrien-ols in tobacco mesophylls, the mesophylls of 35S:NtCBTS2b transgenic tobacco plants were used in the analysis, suggesting that constitutive expression of NtCBTS2b led to the cembratrien-ol production in mesophylls. Overexpression of NtCBTS2b using either Cauliflower mosaic virus (CaMV) 35S or trichome-specific Cyt P450 oxygenase (CYP) promoters greatly increased aphid resistance by promoting the accumulation of CBT-ols, increased the secretory cell growth in glandular trichomes and increased the levels of various physiological measures, including sugar esters, gibberellins, and cembranoid production. Meanwhile, specifically overexpressing NtCBTS2b in glandular trichomes could most efficiently promote aphid resistance in tobacco plants. Notably, our results indicate the feasibility of utilizing bio-engineering to produce large amounts of CBT-ols, and modify significantly the composition of naturally produced CBT-ols and CBT-diols, thereby promoting aphid resistance in plants.

A New Co-P Nanocomposite with Ultrahigh Relaxivity for In Vivo Magnetic Resonance Imaging-Guided Tumor Eradication by Chemo/Photothermal Synergistic Therapy.

Design of new nanoagents that intrinsically have both diagnostic imaging and therapeutic capabilities is highly desirable for personalized medicine. In this work, a novel nanotheranostic agent is fabricated based on polydopamine (PDA)-functionalized Co-P nanocomposites (Co-P@PDA) for magnetic resonance imaging (MRI)-guided combined photothermal therapy and chemotherapy. The ultrahigh relaxivity of 224.61 mm-1 s-1 can enable Co-P@PDA to be applied as an excellent contrast agent for MRI in vitro and in vivo, providing essential and comprehensive information for tumor clinical diagnosis. Moreover, Co-P@PDA exhibit excellent photothermal performance owing to the strong near-infrared (NIR) absorbance of both Co-P nanocomposite and PDA. Highly effective ablation of tumors is achieved in a murine tumor model because the NIR laser not only induces photothermal effects but also triggers the chemotherapeutic drug on-demand release, which endows the Co-P@PDA with high curative effects but little toxicity and few side effects. These findings demonstrate that Co-P@PDA are promising agents for highly effective and precise antitumor treatment and warrant exploration as novel theranostic nanoagents with good potential for future clinical translation.

OsPht1;8, a phosphate transporter, is involved in auxin and phosphate starvation response in rice.

The responses of plants to auxin and phosphate (Pi) starvation are closely linked. However, the underlying mechanisms connecting the Pi starvation (-Pi) responses to auxin are largely unclear. Here, we show that OsPht1;8 (OsPT8), a phosphate transporter, functions in both the auxin and -Pi responses in rice (Oryza sativa L.) and tobacco (Nicotiana tabacum). The overexpression of OsPT8 (OsPT8-Oe) led to the loss of sensitivity to auxin and -Pi in adventitious roots, lateral roots, and root hairs in rice. The expression levels of OsPT8 and pOsPT8::GUS staining in roots, root-shoot junctions and leaves of rice were induced by IAA treatments. The number of young lateral roots in the OsPT8-Oe transgenic rice, which had higher auxin concentrations, was distinctly more than that in the wild-type, possibly as a result of increased expression of auxin-related genes under normal Pi condition. Moreover, tobacco overexpressing OsPT8 had a similar root phenotype to OsPT8-Oe rice. These data reveal a novel biological function of OsPT8 in the cross-talk between Pi and auxin signaling, and provide new evidence for the linkage between auxin and -Pi responses.

Reference Intervals of and Relationships among Essential Trace Elements in Whole Blood of Children Aged 0-14 years.

BACKGROUND: Essential trace elements are vital to human health. In this study, our aim was to establish reference intervals of and to evaluate relationships among Ca, Fe, Cu, Mg, and Zn for children. METHODS: We collected blood samples of 3210 children aged 0-14 years from Lu'an, China, and concentrations of the above elements were determined by atomizer absorption spectrophotometer. A nonparametric method was used to establish the reference intervals. RESULTS: Gender-related differences in concentrations were not statistically significant for the elements, except for Fe. There were strong positive and negative correlations between age and Fe (R = 0.305, P < 0.001), Zn (R = 0.573, P < 0.001); and age and Ca (R = -0.372, P < 0.001), Cu (R = -0.127, P < 0.001), respectively. Correlations between Ca-Mg (r = 0.222~0.384, P < 0.001), Fe-Mg (r = 0.495~0.614, P < 0.001), and Fe-Zn (r = 0.239~0.471, P < 0.001) were the strongest compared with others. In multivariable linear regression, after adjusted for confounding factors, the associations between Zn-Fe and Mg-Fe were the strongest with per concentration quintile increase of Fe caused Zn and Mg increasing by 4.19% (ß = 0.041; 95% CI: 0.037, 0.045; P < 0.001) and 3.87% (ß = 0.038; 95% CI: 0.036, 0.040; P < 0.001), respectively. CONCLUSIONS: Gender- and age-based reference intervals of Ca, Fe, Cu, Mg, and Zn for children were established, and correlations between them were quite complex. More works are needed to illuminate these relationships and their impacts on children's health.

Seasonal Variation of Blood Calcium Levels in Children Aged 1-10.

BACKGROUND: In this study, the associations of seasons with blood calcium levels in children aged 1-10 have not been evaluated. METHODS: In 2012-2014, whole blood samples were collected from 2,562 children and calcium concentrations were determined by flame atomic absorption spectrometry. The associations of seasons with calcium levels were analyzed by multivariable regression. RESULTS: The mean value of calcium concentrations was 1.61 ± 0.13 mmol/l and the overall deficiency was 29.3%. Overall, compared to those in winter, children in spring and summer had significant lower calcium concentrations that decreased by 1.2% (ß = -0.012; 95% CI: -0.021, -0.002) and 1.4% (ß = -0.014; 95% CI: -0.023, -0.005), respectively; and corresponding higher calcium deficiencies than those in spring, summer, and autumn with odds ratios (OR) were 1.93 (95% CI: 1.39, 2.66), 1.65 (95% CI: 1.21, 2.24), and 1.57 (95% CI: 1.14, 2.15), respectively. Moreover, this seasonality was more significant in girls in whom calcium concentration in summer decreased by 1.9% (ß = -0.019; 95% CI: -0.036, -0.003) and OR for calcium deficiencies in summer was 2.46 (1.38-4.41), compared to the girls in winter. CONCLUSIONS: The seasons have significant association with blood calcium levels, especially in girls. However, the impact of this seasonality on children's health is still unknown.

Engineering a Platform for Photosynthetic Pigment, Hormone and Cembrane-Related Diterpenoid Production in Nicotiana tabacum.

Plants synthesize a large number of isoprenoids that are of nutritional, medicinal and industrial importance. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) catalyzes the first committed step for plastidial isoprenoid biosynthesis. Here, we identified two DXR isogenes, designated NtDXR1 and NtDXR2, from tetraploid common tobacco (Nicotiana tabacum L.). Southern blotting and genotyping analysis revealed that two NtDXR genes existed in the tetraploid tobacco genome; NtDXR1 and NtDXR2 were separately derived from N. tomentosiformis and N. sylvestris. Both NtDXRs were localized in chloroplasts. Expression patterns indicated that NtDXR1 and NtDXR2 had similar expression profiles. NtDXR genes were highly expressed in leaves with or without trichomes; expression was relatively reduced in flowers and stems, weak in leaf trichomes and marginal in roots and seeds. Overexpressing NtDXR1 under control of the 35S promoter resulted in longer primary roots and enhancement of various photosynthetic pigments and hormones in leaves. In contrast, there were no significant changes in cembrane-related diterpenoids synthesized in glandular trichomes. To elucidate further the function of DXR in the biosynthesis of diterpenoids, overexpression vectors for NtDXR1 under the control of a trichome-specific CYP promoter were transferred to tobacco plants. CYP:NtDXR1 tobacco exhibited larger glandular cells and increased cembrane-related diterpenoids in leaf glandular trichomes. Moreover, transcripts of eight MEP (2-C-methyl-d-erythritol 4-phosphate) pathway genes were significantly up-regulated in NtDXR1-overexpressing tobacco plants, indicating that overexpression of NtDXR could boost the expression of downstream genes in the MEP pathway. Our results suggested that overexpression of NtDXR1 could increase the levels of photosynthetic pigments, leaf surface exudates and hormones though the MEP pathway.

Cloning and characterization of SnRK2 subfamily II genes from Nicotiana tabacum.

SnRK2 is a plant-specific protein kinase family involved in abiotic stress signalling. In this study, NtSnRK2.1, NtSnRK2.2, and NtSnRK2.3, were cloned from tobacco by in silico cloning and reverse transcription PCR. The three protein kinases were classed into subfamily II of the SnRK2 family using a phylogenetic tree and C-terminus analysis. Subcellular localization revealed NtSnRK2s in the nuclear and cytoplasmic compartments. Dynamic expression of NtSnRK2s in tobacco plants that were exposed to drought, salt, or cold stressors were characterised using quantitative real-time PCR. It was revealed that the three genes showed similar patterns of transcription under abiotic stress responses; there was evidence NtSnRK2s participated in abscisic acid-dependent signalling pathways. NtSnRK2.1-3 responded much faster to drought and salt than to cold stress. To investigate the role of NtSnRK2s under abiotic stresses, NtSnRK2.1 gene was over-expressed in tobacco. A stress tolerance assay showed that tobacco plants that over-expressed NtSnRK2.1 plants had greater salt tolerance. The results indicate that NtSnRK2s are involved in abiotic stress response pathways.

Recent progress of MOF-functionalized nanocomposites: From structure to properties.

Metal-organic frameworks (MOFs) are novel crystalline porous materials assembled from metal ions and organic ligands. The adaptability of their design and the fine-tuning of the pore structures make them stand out in porous materials. Furthermore, by integrating MOF guest functional materials with other hosts, the novel composites have synergistic benefits in numerous fields such as batteries, supercapacitors, catalysis, gas storage and separation, sensors, and drug delivery. This article starts by examining the structural relationship between the host and guest materials, providing a comprehensive overview of the research advancements in various types of MOF-functionalized composites reported to date. The review focuses specifically on four types of spatial structures, including MOFs being (1) embedded in nanopores, (2) immobilized on surface, (3) coated as shells and (4) assembled into hybrids. In addition, specific design ideas for these four MOF-based composites are presented. Some of them involve in situ synthesis method, solvothermal method, etc. The specific properties and applications of these materials are also mentioned. Finally, a brief summary of the advantages of these four types of MOF composites is given. Hopefully, this article will help researchers in the design of MOF composite structures.

Analysis and Prevention of Rock Burst Risk of Working Face under the Influence of Continuous Irregular Triangular Coal Pillar Stress Concentration Area.

Irregular coal pillars inevitably appear in the layout of the current long-wall mining method, which easily forms stress concentrations and becomes a heavy disaster area of rock burst. In order to solve the impact risk of irregular coal pillar working face, it is necessary to study the instability mechanism of the coal pillar and put forward effective prevention and control measures. Based on the research background of 14320 working face of the Dongtan Coal Mine in the Yanzhou mining area of China, this paper studies the prediction and prevention of rock bursts in this kind of coal pillar by means of theoretical calculation, numerical simulation, engineering analogy, and field monitoring. The results show that (1) the absolute stability of coal pillar is that the width of coal pillar B reaches twice the support pressure of 2L, and the possibility of instability from large to small is coal pillars 2, 5, 3, 1, and 4. (2) The ratio of coal pillar strength to its average load determines the stability coefficient of the coal pillar, and it is judged that coal pillars 1 and 4 are in a stable state, coal pillars 3 and 5 are in a limit equilibrium state, and coal pillar 2 is in an unstable state. The numerical simulation shows that the maximum stress value inside the coal pillar during the mining process is basically consistent with the theoretical calculation of the bearing strength of the coal pillar. (3) The new evaluation method is used to evaluate the rock burst risk degree of the working face roadway: 156.75 m is a strong rock burst risk zone, 728.18 m is a medium rock burst risk zone, and 176.88 m is a weak rock burst risk zone. (4) Regional prevention and local prevention measures are proposed for the risk of rock burst in the roadway, which reduces the stress concentration of the coal pillar. It is verified that the pressure relief effect is remarkable, and the safe mining of such an irregular coal pillar working face is completed, which provides a solution for studying and solving such rock burst risk.

Stabilizing electron-rich Ni single-atoms on black phosphorus nanosheets boosts photocatalytic carbon dioxide reduction.

The development of unique single-atom catalysts with electron-rich feature is essential to promoting the photocatalytic CO2 reduction, yet remains a big challenge. Here, a conceptionally new single-atom catalyst constructed from atomically dispersed Ni-P3 species on black phosphorus (BP) nanosheets (BP-Ni) is synthesized for realizing highly efficient visible-light-driven CO2 reduction when trapping photogenerated electrons from homogeneous light absorbers in the presence of triethanolamine as the sacrificial agent. Both the experimental and theoretical calculation data reveal that the Ni-P3 species on BP nanosheets own the electron-rich feature that can improve the photogenerated charge separation efficiency and lower the activation barrier of CO2 conversion. This unique feature makes BP-Ni exhibit the much higher activity as cocatalyst in the photocatalytic CO2 reduction than BP nanosheets. The BP-Ni can also be applied as a cocatalyst for enhanced photocatalytic CO2 reduction after combining with CdSe/S colloidal crystal photocatalyst. The present study offers valuable inspirations for the design and construction of effective catalytic sites toward photocatalytic CO2 reduction reactions.