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Congenital anomalies of the lower genitourinary (LGU) tract are frequently comorbid due to genetically linked developmental pathways, and are among the most common yet most socially stigmatized congenital phenotypes. Genes involved in sexual differentiation are prime candidates for developmental anomalies of multiple LGU organs, but insufficient prospective screening tools have prevented the rapid identification of causative genes. Androgen signaling is among the most influential modulators of LGU development. The present study uses SpDamID technology in vivo to generate a comprehensive map of the pathways actively regulated by the androgen receptor (AR) in the genitalia in the presence of the p300 coactivator, identifying wingless/integrated (WNT) signaling as a highly enriched AR-regulated pathway in the genitalia. Transcription factor (TF) hits were then assayed for sexually dimorphic expression at two critical time points and also cross-referenced to a database of clinically relevant copy number variations to identify 252 TFs exhibiting copy variation in patients with LGU phenotypes. A subset of 54 TFs was identified for which LGU phenotypes are statistically overrepresented as a proportion of total observed phenotypes. The 252 TF hitlist was then subjected to a functional screen to identify hits whose silencing affects genital mesenchymal growth rates. Overlap of these datasets results in a refined list of 133 TFs of both functional and clinical relevance to LGU development, 31 of which are top priority candidates, including the well-documented renal progenitor regulator, Sall1. Loss of Sall1 was examined in vivo and confirmed to be a powerful regulator of LGU development.
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Variações do Número de Cópias de DNA , Sistema Urinário , Humanos , Estudos Prospectivos , Androgênios/metabolismo , Genitália/metabolismo , Sistema Urinário/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The development of advanced neural modulation techniques is crucial to neuroscience research and neuroengineering applications. Recently, optical-based, nongenetic modulation approaches have been actively investigated to remotely interrogate the nervous system with high precision. Here, we show that a thin-film, silicon (Si)-based diode device is capable to bidirectionally regulate in vitro and in vivo neural activities upon adjusted illumination. When exposed to high-power and short-pulsed light, the Si diode generates photothermal effects, evoking neuron depolarization and enhancing intracellular calcium dynamics. Conversely, low-power and long-pulsed light on the Si diode hyperpolarizes neurons and reduces calcium activities. Furthermore, the Si diode film mounted on the brain of living mice can activate or suppress cortical activities under varied irradiation conditions. The presented material and device strategies reveal an innovated optoelectronic interface for precise neural modulations.
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Neurônios , Optogenética , Silício , Animais , Silício/química , Neurônios/fisiologia , Camundongos , Optogenética/métodos , Cálcio/metabolismo , Luz , Encéfalo/fisiologiaRESUMO
Shade avoidance syndrome (SAS) is triggered by a low ratio of red (R) to far-red (FR) light (R/FR ratio), which is caused by neighbor detection and/or canopy shade. In order to compete for the limited light, plants elongate hypocotyls and petioles by deactivating phytochrome B (phyB), a major R light photoreceptor, thus releasing its inhibition of the growth-promoting transcription factors PHYTOCHROME-INTERACTING FACTORs. Under natural conditions, plants must cope with abiotic stresses such as drought, soil salinity, and extreme temperatures, and biotic stresses such as pathogens and pests. Plants have evolved sophisticated mechanisms to simultaneously deal with multiple environmental stresses. In this review, we will summarize recent major advances in our understanding of how plants coordinately respond to shade and environmental stresses, and will also discuss the important questions for future research. A deep understanding of how plants synergistically respond to shade together with abiotic and biotic stresses will facilitate the design and breeding of new crop varieties with enhanced tolerance to high-density planting and environmental stresses.
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Proteínas de Arabidopsis , Fitocromo , Luz , Melhoramento Vegetal , Plantas , Estresse FisiológicoRESUMO
The pathological misfolding and aggregation of soluble α-synuclein into toxic oligomers and insoluble amyloid fibrils causes Parkinson's disease, a progressive age-related neurodegenerative disease for which there is no cure. HET-s is a soluble fungal protein that can form assembled amyloid fibrils in its prion state. We engineered HET-s(218-298) to form four different fibrillar vaccine candidates, each displaying a specific conformational epitope present on the surface of α-synuclein fibrils. Vaccination with these four vaccine candidates prolonged the survival of immunized TgM83+/- mice challenged with α-synuclein fibrils by 8% when injected into the brain to model brain-first Parkinson's disease or by 21% and 22% when injected into the peritoneum or gut wall, respectively, to model body-first Parkinson's disease. Antibodies from fully immunized mice recognized α-synuclein fibrils and brain homogenates from patients with Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. Conformation-specific vaccines that mimic epitopes present only on the surface of pathological fibrils but not on soluble monomers, hold great promise for protection against Parkinson's disease, related synucleinopathies and other amyloidogenic protein misfolding disorders.
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Camundongos Transgênicos , Doença de Parkinson , alfa-Sinucleína , Animais , Doença de Parkinson/imunologia , Doença de Parkinson/patologia , Camundongos , alfa-Sinucleína/imunologia , alfa-Sinucleína/metabolismo , Humanos , Amiloide/imunologia , Amiloide/metabolismo , Vacinação , Proteínas Fúngicas/imunologia , Encéfalo/patologia , Encéfalo/metabolismo , Encéfalo/imunologia , Feminino , Camundongos Endogâmicos C57BLRESUMO
Osteoarthritis (OA) is one of the most prevalent joint diseases in aged people and characterized by articular cartilage degeneration, synovial inflammation, and abnormal bone remodeling. Recent advances in OA research have clearly shown that OA development is associated with aberrant DNA methylation status of many OA-related genes. As one of most important cartilage degrading proteases in OA, a disintegrin and metalloproteinase with thrombospondin motifs subtype 5 (ADAMTS-5) is activated to mediate cartilage degradation in human OA and experimental murine OA models. The pathological factors and signaling pathways mediating ADAMTS-5 activation during OA development are not well defined and have been a focus of intense research. ADAMTS-5 promoter is featured by CpG islands. So far there have been no reports concerning the DNA methylation status in ADAMTS-5 promoter during OA development. In this study, we sought to investigate DNA methylation status in ADAMTS-5 promoter, the role of DNA methylation in ADAMTS-5 activation in OA, and the underlying mechanisms. The potential for anti-OA intervention therapy which is based on modulating DNA methylation is also explored. Our results showed that DNA methyltransferases 1 (Dnmt1) downregulation-associated ADAMTS-5 promoter demethylation played an important role in ADAMTS-5 activation in OA, which facilitated SPI-1 binding on ADAMTS-5 promoter to activate ADAMTS-5 expression. More importantly, OA pathological phenotype of mice was alleviated in response to Dnmt1-induced DNA methylation of ADAMTS-5 promoter. Our study will benefit not only for deeper insights into the functional role and regulation mechanisms of ADAMTS-5 in OA, but also for the discovery of disease-modifying OA drugs on the basis of ADAMTS-5 via modulating DNA methylation status.
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Cartilagem Articular , Peptídeos e Proteínas de Sinalização Intercelular , Osteoartrite , Idoso , Animais , Humanos , Masculino , Camundongos , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Desmetilação do DNA , Células HEK293 , Camundongos Endogâmicos C57BL , Osteoartrite/patologia , Regiões Promotoras Genéticas/genéticaRESUMO
Hydrides are promising candidates for achieving room-temperature superconductivity, but a formidable challenge remains in reducing the stabilization pressure below a megabar. In this study, we successfully synthesized a ternary lanthanum borohydride by introducing the nonmetallic element B into the La-H system, forming robust B-H covalent bonds that lower the pressure required to stabilize the superconducting phase. Electrical transport measurements confirm the presence of superconductivity with a critical temperature (Tc) of up to 106 K at 90 GPa, as evidenced by zero resistance and Tc shift under an external magnetic field. X-ray diffraction and transport measurements identify the superconducting compound as LaB2H8, a nonclathrate hydride, whose crystal structure remains stable at pressures as low as â¼ half megabar (59 GPa). Stabilizing superconductive stoichiometric LaB2H8 in a submegabar pressure regime marks a substantial advancement in the quest for high-Tc superconductivity in polynary hydrides, bringing us closer to the ambient pressure conditions.
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Herein, the aptamer-antibody sandwich module was first introduced to accurately recognize a low molecular weight compound (mycotoxin). Impressively, compared with the large steric hindrance of a traditional dual-antibody module, the aptamer-antibody sandwich with low Gibbs free energy and a low dissociation constant has high recognition efficiency; thus, it could reduce false positives and false negatives caused by a dual-antibody module. As a proof of concept, a sensitive electrochemiluminescence (ECL) biosensor was constructed for detecting mycotoxin zearalenone (ZEN) based on an aptamer-antibody sandwich as a biological recognition element and porous ZnO nanosheets (Zn NSs) supported Cu nanoclusters (Cu NCs) as the signal transduction element, in which the antibody was modified on the vertex of a tetrahedral DNA nanostructure (TDN) with a rigid structure to increase the kinetics of target recognition for promoting the detection sensitivity. Moreover, the Cu NCs/Zn NSs exhibited an excellent ECL response that was attributed to the aggregation-induced ECL enhancement through electrostatic interactions. The sensing platform achieved trace detection of ZEN with a low detection limit of 0.31 fg/mL, far beyond that of the enzyme-linked immunosorbent assay (ELISA, the current rapid detection method) and high-performance liquid chromatography (HPLC, the national standard detection method). The strategy has great application potential in food analysis, environmental monitoring, and clinical diagnosis.
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Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Técnicas Eletroquímicas , Zearalenona , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Zearalenona/análise , Zearalenona/imunologia , Técnicas Eletroquímicas/métodos , Cobre/química , Limite de Detecção , Anticorpos/química , Anticorpos/imunologia , Medições Luminescentes/métodos , Óxido de Zinco/química , Peso MolecularRESUMO
Nanogap-based plasmonic metal nanocrystals have been applied in surface-enhanced Raman scattering detection, while the closed and insufficient electromagnetic fields as well as the nonreproducible Raman signal of the substrate greatly restrict the actual application. Herein, a highly uniform Au/AgAu monolayer with abundant nanogaps and huge electromagnetic enhancement is prepared, which shows ultrasensitive and reproducible SERS detection. Au/AgAu with an inner nanogap is first prepared based on Au nanotriangles, and the nanogap is opened from the three tips via a subsequent etching process. The open-gap Au/AgAu displays much higher SERS efficiency than Au and Au/AgAu with an inner nanogap on detecting crystal violet due to the open-gap induced electromagnetic enhancement and improved molecular absorption. Furthermore, the open-gap Au/AgAu monolayer is prepared via interfacial self-assembly, which shows further improved SERS due to the dense and strong hotspots in the nanocavities induced by the electromagnetic coupling between adjacent open gaps. The monolayer possesses excellent signal stability, uniformity, and reproducibility. The analytic enhancement factor and relative standard deviation reach to 2.12 × 108 and 4.65% on detecting crystal violet, respectively. Moreover, the monolayer achieves efficient detection of thiram in apple juice, biphenyl-4-thiol, 4-mercaptobenzoic, melamine, and a mixed solution of four different molecules, showing great promise in practical detection.
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Comprising numerous subnuclei, the thalamus intricately interconnects the cortex and subcortex, orchestrating various facets of brain functions. Extracting personalized parcellation patterns for these subnuclei is crucial, as different thalamic nuclei play varying roles in cognition and serve as therapeutic targets for neuromodulation. However, accurately delineating the thalamic nuclei boundary at the individual level is challenging due to intersubject variability. In this study, we proposed a prior-guided parcellation (PG-par) method to achieve robust individualized thalamic parcellation based on a central-boundary prior. We first constructed probabilistic atlas of thalamic nuclei using high-quality diffusion MRI datasets based on the local diffusion characteristics. Subsequently, high-probability voxels in the probabilistic atlas were utilized as prior guidance to train unique multiple classification models for each subject based on a multilayer perceptron. Finally, we employed the trained model to predict the parcellation labels for thalamic voxels and construct individualized thalamic parcellation. Through a test-retest assessment, the proposed prior-guided individualized thalamic parcellation exhibited excellent reproducibility and the capacity to detect individual variability. Compared with group atlas registration and individual clustering parcellation, the proposed PG-par demonstrated superior parcellation performance under different scanning protocols and clinic settings. Furthermore, the prior-guided individualized parcellation exhibited better correspondence with the histological staining atlas. The proposed prior-guided individualized thalamic parcellation method contributes to the personalized modeling of brain parcellation.
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Núcleos Talâmicos , Tálamo , Humanos , Reprodutibilidade dos Testes , Tálamo/diagnóstico por imagem , Encéfalo , Córtex CerebralRESUMO
MAIN CONCLUSION: Overexpression of OsNRT1.1A promotes early heading and increases the tolerance in wheat under nitrogen deficiency conditions. The application of inorganic nitrogen (N) fertilizers is a major driving force for crop yield improvement. However, the overuse of fertilizers significantly raises production costs and leads to environmental problems, making it critical to enhance crop nitrogen use efficiency (NUE) for the sake of sustainable agriculture. In this study, we created a series of transgenic wheat lines carrying the rice OsNRT1.1A gene, which encodes a nitrate transporter, to investigate its possible application in improving NUE in wheat. The transgenic wheat exhibited traits such as early maturation that were highly consistent with the overexpression of OsNRT1.1A in Arabidopsis and rice. However, we also observed that overexpression of the OsNRT1.1A gene in wheat can facilitate the growth of roots under low N conditions but has no effect on other aspects of growth and development under normal N conditions. Thus, it may lead to the improvement of wheat low N tolerance,which is different from the effects reported in other plants. A field trial analysis showed that transgenic wheat exhibited increased grain yield per plant under low N conditions. Moreover, transcriptome analysis indicated that OsNRT1.1A increased the expression levels of N uptake and utilization genes in wheat, thereby promoting plant growth under low N conditions. Taken together, our results indicated that OsNRT1.1A plays an important role in improving NUE in wheat with low N availability.
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Arabidopsis , Oryza , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oryza/genética , Oryza/metabolismo , Triticum , Nitrogênio/metabolismo , Fertilizantes , Arabidopsis/metabolismoRESUMO
BACKGROUND: Telomere length has long been recognized as a valuable biomarker of aging and is inversely correlated with chronological age. Various lifestyle factors have been implicated in telomere shortening or preservation; however, the association between lifestyle factors and telomere length remains controversial. To address this issue, we conducted a Mendelian randomization (MR) analysis to investigate the potential causal associations between multiple lifestyle factors and telomere length. METHODS: Independent genetic variants strongly associated with lifestyle factors (tobacco smoking, sleep duration, insomnia, and physical activity) were selected as instrumental variables from corresponding genome-wide association studies (GWASs). Summary-level data for telomere length was obtained from a GWAS comprising 472,174 European ancestries. Univariable and multivariable MR analyses were performed to assess the relationships. RESULTS: The genetic liability to lifetime smoking was robustly associated with shorter telomere length (odd ratio [OR]: 0.882; 95% confidence interval [CI]: 0.847-0.918). Genetically predicted insomnia was also linked to shorter telomere length (OR: 0.972; 95% CI: 0.959-0.985), while no significant association was observed between sleep duration and telomere length. Furthermore, a suggestive association was found between moderate-to-vigorous physical activity and longer telomere length (OR: 1.680; 95% CI: 1.115-2.531). In multivariable MR analyses, adjusting for potential mediators such as body mass index, type 2 diabetes, alcohol consumption, and alcohol use disorder, the associations of lifetime smoking and insomnia with telomere length remained robust. CONCLUSION: Our findings suggest that smoking and insomnia may contribute to telomere shortening, while physical activity may play a role in telomere length maintenance. These findings underscore the importance of managing positive risk factors and adopting a healthy lifestyle to promote telomere health.
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Diabetes Mellitus Tipo 2 , Distúrbios do Início e da Manutenção do Sono , Humanos , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Telômero/genética , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: Uveal melanoma (UM), the most common adult intraocular tumor, is characterized by high malignancy and poor prognosis in advanced stages. Angiogenesis is critical for UM development, however, not only the role of vascular endothelial dysfunction in UM remains unknown, but also their analysis at the single-cell level has been lacking. A comprehensive analysis is essential to clarify the role of the endothelium in the development of UM. METHODS: By using single-cell RNA transcriptomics data of 11 cases of primary and liver metastasis UM, we analyzed the endothelial cell status. In addition, we analyzed and validated ECs in the in vitro model and collected clinical specimens. Subsequently, we explored the impact of endothelial dysfunction on UM cell migration and explored the mechanisms responsible for the endothelial cell abnormalities and the reasons for their peripheral effects. RESULTS: UM metastasis has a significantly higher percentage of vascular endothelial cells compared to in situ tumors, and endothelial cells in metastasis show significant senescence. Senescent endothelial cells in metastatic tumors showed significant Krüppel-like factor 4 (KLF4) upregulation, overexpression of KLF4 in normal endothelial cells induced senescence, and knockdown of KLF4 in senescent endothelium inhibited senescence, suggesting that KLF4 is a driver gene for endothelial senescence. KLF4-induced endothelial senescence drove tumor cell migration through a senescence-associated secretory phenotype (SASP), of which the most important component of the effector was CXCL12 (C-X-C motif chemokine ligand 12), and participated in the composition of the immunosuppressive microenvironment. CONCLUSION: This study provides an undesirable insight of senescent endothelial cells in promoting UM metastasis.
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Movimento Celular , Senescência Celular , Células Endoteliais , Fator 4 Semelhante a Kruppel , Neoplasias Hepáticas , Melanoma , Análise de Célula Única , Neoplasias Uveais , Humanos , Neoplasias Uveais/patologia , Neoplasias Uveais/genética , Melanoma/patologia , Melanoma/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/genética , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Linhagem Celular Tumoral , Quimiocina CXCL12/metabolismo , Quimiocina CXCL12/genética , Regulação Neoplásica da Expressão Gênica , Feminino , MasculinoRESUMO
Mycorrhizal associations are key mutualisms that shape the structure of forest communities and multiple ecosystem functions. However, we lack a framework for predicting the varying dominance of distinct mycorrhizal associations in an integrated proxy of multifunctionality across ecosystems. Here, we used the datasets containing diversity of mycorrhizal associations and 18 ecosystem processes related to supporting, provisioning, and regulating services to examine how the dominance of ectomycorrhiza (EcM) associations affects ecosystem multifunctionality in subtropical mountain forests in Southwest China. Meanwhile, we synthesized the prevalence of EcM-dominant effects on ecosystem functioning in forest biomes. Our results demonstrated that elevation significantly modified the distributions of EcM trees and fungal dominance, which in turn influenced multiple functions simultaneously. Multifunctionality increased with increasing proportion of EcM associations, supporting the ectomycorrhizal-dominance hypothesis. Meanwhile, we observed that the impacts of EcM dominance on individual ecosystem functions exhibited different relationships among forest biomes. Our findings highlight the importance of ectomycorrhizal dominance in regulating multifunctionality in subtropical forests. However, this ectomycorrhizal feedback in shaping ecosystem functions cannot necessarily be generalized across forests. Therefore, we argue that the predictions for ecosystem multifunctionality in response to the shifts of mycorrhizal composition could vary across space and time.
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Inflammation is associated with thoracic aortic aneurysm (TAA) but the effects of each circulating inflammatory factor on TAA remain unclear. In this study, we explored the relationship between circulating inflammatory factors and TAA risk using Mendelian randomization (MR) approach based on summary statistics from the latest genome-wide association study (GWAS) of 41 circulating inflammatory factors in 8293 Finns and a GWAS involving 1351 TAA cases and 18,295 controls of European ancestry. In univariable MR, higher interferon gamma-induced protein 10 (IP-10) levels, higher interferon gamma (IFNγ) levels and higher stem cell growth factor beta (SCGFß) levels were associated with an increased risk of TAA (OR = 1.37, 95 % CI = 1.17-1.59, p = 7.42 × 10-5; OR = 1.43, 95 % CI = 1.19-1.74, p = 2.04 × 10-4; OR = 1.27, 95 % CI = 1.09-1.48, p = 2.40 × 10-3, respectively). In multivariable MR, the patterns of associations for the three cytokines remained adjusting for each other or smoking, but were attenuated differently with adjustment for other cardiovascular risk factors, especially for lipids and body mass index. Bidirectional MR approach did not identify any significant associations between cytokines and risk factors. Our results indicated that circulating cytokines may play mediation roles in the pathogenesis of TAA. Further studies are needed to determine whether these biomarkers can be used to prevent and treat TAA.
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Aneurisma da Aorta Torácica , Interferon gama , Humanos , Interferon gama/genética , Quimiocina CXCL10 , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Citocinas , Aneurisma da Aorta Torácica/genéticaRESUMO
Electrocatalytic reduction (ECR) of CO2 to chemical products is an important carbon emission reduction method. This work uses DFT to study the stability of N-doped graphene-supported four metal single-atom catalysts (M-N-C) and the effects of the coordination environment and metal centers on the selectivity of CO2 ECR to C1 products. The results show that Fe, Co, Ni, and Cu have good stability. The coordination environment has a significant modulating effect on product selectivity, and the change of the number of ligand nitrogen atoms will affect the size of the potential-limiting step of each product. When the number of nitrogen ligands is the same, the different metal centers of the M-N-C catalyst have a significant effect on the selectivity of different products. In addition, the introduction of nitrogen atom ligands can adjust the electronic structure of the graphene-supported metal center, increase the d-band center of most metals, and improve the reaction activity.
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Spinal cord injury (SCI) is a complex problem in modern medicine. Fibroblast activation and fibroscarring after SCI impede nerve recovery. Non-coding RNA plays an important role in the progression of many diseases, but the study of its role in the progression of spinal fibrosis is still emerging. Here, we investigated the function of circular RNAs, specifically antisense to the cerebellar degeneration-related protein 1 (CDR1as), in spinal fibrosis and characterized its molecular mechanism and pathophysiology. The presence of CDR1as in the spinal cord was verified by sequencing and RNA expression assays. The effects of inhibition of CDR1as on scar formation, inflammation and nerve regeneration after spinal cord injury were investigated in vivo and in vitro. Further, gene expression of miR-7a-5p and protein expression of transforming Growth Factor Beta Receptor II (TGF-ßR2) were measured to evaluate their predicted interactions with CDR1as. The regulatory effects and activation pathways were subsequently verified by miR-7a-5p inhibitor and siCDR1as. These results indicate that CDR1as/miR-7a-5p/TGF-ßR2 interactions may exert scars and nerves functions and suggest potential therapeutic targets for treating spinal fibrotic diseases.
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Fibrose , MicroRNAs , RNA Circular , RNA Longo não Codificante , Transdução de Sinais , Traumatismos da Medula Espinal , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/fisiopatologia , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia , Proteínas Smad/metabolismo , Proteínas Smad/genética , Regeneração Nervosa , Feminino , Masculino , Receptor do Fator de Crescimento Transformador beta Tipo II/genética , Receptor do Fator de Crescimento Transformador beta Tipo II/metabolismo , Camundongos Endogâmicos C57BL , Camundongos , Recuperação de Função FisiológicaRESUMO
In this study, new hybrid birefringent crystals of (C8H7N2O2)2[Bi2Br8]·2H2O and (C8H7N2O2)6[Bi2Cl10]Cl2·2H2O were successfully synthesized by introducing a new birefringent group [C8H7N2O2]+ by a simple aqueous solution evaporation method. They crystallize in the P21/n space group, and their structure consists mainly of the π-conjugated group [C8H7N2O2]+ and the octahedron centered on Bi3+. By first-principles calculations, the birefringence response comes from the [C8H7N2O2]+ group with a planar π-conjugated structure. Meanwhile, the synthesis, structure, first-principles calculations, and optical properties are reported in this paper.
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Nonlinear optical (NLO) crystals are widely used in various fields. The introduction of lone-pair cations is regarded as an effective strategy to explore NLO crystals. In this work, two novel lead phosphite halides, centrosymmetric Pb6(HPO3)(H2PO3)Cl9 and noncentrosymmetric Pb6(HPO3)2Br8(H2O)·H2O, were obtained via a hydrothermal method. Pb6(HPO3)(H2PO3)Cl9 is the first reported lone-pair metal phosphite with two kinds of phosphite groups (HPO32- and H2PO3-) and Pb6(HPO3)2Br8(H2O)·H2O is the first inorganic NLO phosphite halide with a phase-matchable SHG effect of 1.02 × KDP. In addition, the Pb-centered polyhedral units of PbOCl4, PbOCl6, PbO2Cl5, PbO2Br5, PbOBr6, and PbO3(H2O)Br3 in these two structures have never been reported before. An in-depth study on the structure-property relationship of the two compounds with halogen substitution is also performed.
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Effective design and synthesis of second-order nonlinear optical (NLO) materials hold immense significance in driving modern science and technology advancements. In this study, we synthesized a new acentric mercury nitrate, (C5H12N2S)Hg(NO3)2, by regulating the coordination of the Hg atom through the introduction of a heteroatom. It exhibits an unprecedented [(C5H12N2S)2Hg2(NO3)4]∞ chain composed of Hg2+, NO3-, and organic molecule C5H12N2S. Notably, (C5H12N2S)Hg(NO3)2 demonstrates an unprecedented HgO3S unit and a second harmonic generation (SHG) intensity of 1.3 × KDP at 1064 nm, presenting the second-order nonlinear mercury nitrate constructed by organic molecule. Theoretical calculations suggest that the HgO3S unit and organic molecule C5H12N2S significantly contribute to the SHG effect. This study demonstrates that the incorporation of heteroatoms is an effective strategy for the development of new NLO materials.
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Exploring ultraviolet (UV) nonlinear-optical (NLO) materials is significant for the conversion of a high-frequency laser. Two scandium phosphites, Sc(HPO3)(H2PO3)(H2O) and Sc(H2PO3)3, were successfully synthesized. Centric Sc(HPO3)(H2PO3)(H2O) exhibits a short UV cutoff edge (<200 nm) and a unique double-layer structure of [Sc2(HPO3)2(H2PO3)2(H2O)2]∞. The acentric Sc(H2PO3)3 exhibits a three-dimensional [Sc(H2PO3)3]∞ structure with a large band gap of 4.05 eV, and it demonstrates a moderately phase-matchable second-harmonic-generation response [0.60 × KDP (KH2PO4)] at 1064 nm. The crystal structures, optical properties, and theoretical calculations of the two compounds are discussed. This work will promote the exploration of new NLO phosphite materials.