RESUMO
Metal-semiconductor heterostructured catalysts have attracted great attention because of their unique interfacial characteristics and superior catalytic performance. Exsolution of nanoparticles is one of the effective and simple ways for in-situ growth of metal nanoparticles embedded in oxide surfaces and their favorable dispersion and stability. However, both high-temperature and a reducing atmosphere are required simultaneously in conventional exsolution, which is time-consuming and costly, and particles often agglomerate during the process. In this work, Ca0.9Ti0.8Ni0.1Fe0.1O3-δ (CTNF) is exposed to dielectric blocking discharge (DBD) plasma at room temperature to fabricate alloying FeNi3 nanoparticles from CTNF perovskite. FeNi3-CTNF has outstanding catalytic activity for photothermal reverse water gas shift reaction (RWGS). At 350 °C under full-spectrum irradiation, the carbon monoxide (CO) yield of FeNi3-CTNF (10.78 mmol g-1 h-1) is 11 times that of pure CaTiO3(CTO), and the CO selectivity is 98.9%. This superior catalytic activity is attributed to the narrow band gap, photogenerated electron migration to alloy particles, and abundant surface oxygen vacancies. The carbene pathway reaction is also investigated through in-situ Raman spectroscopy. The present work presents a straightforward method for the exsolution of nanoalloys in metal-semiconductor heterostructures for photothermal CO2 reduction.
RESUMO
Vertical profiles of aerosol light scattering (bscat), absorption (babs), as well as the single scattering albedo (SSA, ω), play an important role in the effects of aerosols on climate, air quality, and local photochemistry. High-precision in-situ measurements of the vertical profiles of these properties are challenging and therefore uncommon. We report here the development of a portable cavity-enhanced albedometer operating at λ = 532â nm for use aboard an unmanned aerial vehicle (UAV). Multi-optical parameters, bscat, babs, extinction coefficient bext, and ω, can be measured simultaneously in the same sample volume. The achieved detection precisions in laboratory were 0.38, 0.21, and 0.43 Mm-1 for bext, bscat, and babs, respectively, for a 1 s data acquisition time. The albedometer was installed on an hexacopter UAV and simultaneous in-situ measurements of the vertical distributions of bext, bscat, babs, and ω were realized for the first time. Here we report a representative vertical profile up to a maximum height of 702 m with a vertical resolution of better than 2 m. The UAV platform and the albedometer demonstrate good performance and will be a valuable and powerful tool for atmospheric boundary layer research.
RESUMO
In the urban atmosphere, nitrogen oxide (NOxâNO + NO2)-related reactions dominate the formation of nitrous acid (HONO). Here, we validated an external cycling route of HONO and NOx, i.e., formation of HONO resulting from precursors other than NOx, in the background atmosphere. A chemical budget closure experiment of HONO and NOx was conducted at a background site on the Tibetan Plateau and provided direct evidence of the external cycling. An external daytime HONO source of 100 pptv h-1 was determined. Both soil emissions and photolysis of nitrate on ambient surfaces constituted likely candidate mechanisms characterizing this external source. The external source dominated the chemical production of NOx with HONO as an intermediate tracer. The OH production was doubled as a result of the external cycling. A high HONO/NOx ratio (0.31 ± 0.06) during the daytime was deduced as a sufficient condition for the external cycling. Literature review suggested the prevalence of high HONO/NOx ratios in various background environments, e.g., polar regions, pristine mountains, and forests. Our analysis validates the prevalence of external cycling in general background atmosphere and highlights the promotional role of external cycling regarding the atmospheric oxidative capacity.
Assuntos
Nitrogênio , Ácido Nitroso , Ácido Nitroso/análise , Ácido Nitroso/química , Óxidos de Nitrogênio/análise , Nitratos , Óxido Nítrico , Atmosfera/químicaRESUMO
Being major species of atmospheric reactive nitrogen, nitrogen oxides (NOx = NO + NO2) have important implications for ozone and OH radical formation in addition to nitrogen cycles. Stable nitrogen isotopes (δ15N) of NOx have been sought to track NOx emissions and NOx chemical reactivities in the atmosphere. The current atmospheric NOx collection methods for isotopic analysis, however, largely suffer from unverified collection efficiency and/or low collection speed (<10 L/min). The latter makes it difficult to study δ15N(NOx) in pristine regions with low NOx concentrations. Here, we present a three-dimensional (3D)-printed honeycomb denuder (3DP-HCD) system, which can effectively collect atmospheric NO2 (a major part of NOx) under a variety of laboratory and field conditions. With a coating solution consisting of 10% potassium hydroxide (KOH) and 25% guaiacol in methanol, the denuder system can collect NO2 with nearly 100% efficiency at flow rates of up to 70 L/min, which is 7 times higher than that of the existing method and allows high-resolution (e.g., diurnal or finer resolution) NO2 collection even in pristine sites. Besides, the δ15N of NO2 collected by the 3DP-HCD system shows good reproducibility and consistency with the previously tested method. Preliminary results of online NO oxidation by a chrome trioxide (CrO3) oxidizer for simultaneous NO and NO2 collection are also presented and discussed.
Assuntos
Poluentes Atmosféricos , Ozônio , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Guaiacol/análise , Metanol/análise , Nitrogênio/análise , Dióxido de Nitrogênio , Isótopos de Nitrogênio/análise , Óxidos de Nitrogênio/análise , Ozônio/análise , Impressão Tridimensional , Reprodutibilidade dos TestesRESUMO
Accurate and sensitive measurements of NO2 play an extremely important role in atmospheric studies. Increasingly, studies require NO2 measurements with parts per trillion by volume (pptv-level) detection limits. Other desirable instrument attributes include ease of use, long-term stability, and low maintenance. In this work, we report the development of an amplitude-modulated multimode-diode-laser-based cavity-enhanced absorption spectroscopy (AM-CEAS) system operating at 406 nm that uses phase-sensitive detection for extremely sensitive NO2 detection. The laser was TTL-modulated at 35 kHz. The mirror reflectivity was determined to be 99.985% based on the ring-down time measurement. The cavity base length was 47.5 cm, giving an effective absorption pathlength of â¼3.26 km. AM-CEAS achieved a 1σ detection precision of 35 pptv in a 1 s data acquisition time (4.98 × 10-10 cm-1), over 4 times lower than that attained using a ring-down approach and the same optical system. The AM-CEAS precision improved to 8 pptv over a data acquisition time of 30 s (1.14 × 10-10 cm-1). The AM-CEAS method with the multimode diode laser integrates the advantages of high light injection efficiency like on-axis alignment cavity ring-down spectroscopy, low cavity-mode noise like off-axis alignment CEAS, and narrow-bandwidth high-sensitivity weak signal detection of modulation spectroscopy, providing a powerful, straightforward, and general method for ultrasensitive absorption and extinction measurements.
Assuntos
Lasers , Dióxido de Nitrogênio , Luz , Análise Espectral/métodosRESUMO
LnMnO3+σ (Ln = La, Pr, Nd, Sm, Eu, Gd or Dy) perovskites synthesized by sol-gel method were employed for gaseous elemental mercury (Hg0) removal from coal-fired flue gas. Characterization results revealed the structure of the perovskites presented a phase transition process from rhombohedral system to O- and O'-orthorhombic structure with the change of A-site rare earth elements. The perovskites showed satisfactory Hg0 removal capacity in a narrow temperature range of 100-150°C. NdMnO3+σ with an O-O' orthorhombic structure presented the best Hg0 removal performance, which markedly depends on four factors: crystal structure, oxygen vacancy density, Mn4+/Mn3+ ratio and surface element segregation. The Hg0 removal mechanism was illustrated based on the mercury temperature programmed desorption experiment and X-ray photoelectron spectroscopy characterization. Both chemisorption and catalytic oxidation played a role in the Hg0 removal process. Chemisorption dominated the Hg0 removal, due to the slow catalytic oxidation rate at low temperature. This work preliminarily established the relation between the structure of rare earth manganese perovskite and Hg0 removal performance.
Assuntos
Poluentes Atmosféricos , Mercúrio , Compostos de Cálcio , Carvão Mineral , Óxidos , Temperatura , TitânioRESUMO
The stronger coordination ability of mercury ions with organic ligands than the metal ions in metal organic framework (MOFs) provides an accessible way to separate mercury ions from solution using specific MOFs. In this study, a Co-based MOF (ZIF-67, Co(mIM)2) was synthesized. It did not introduce specific functional groups, such as -SH and -NH2, into its structure through complicated steps. It separate Hg2+ from wastewater with a new strategy, which utilized the stronger coordination ability of Hg2+ with the nitrogen atom on the imidazole ring of the organic ligand than the Co2+ ions. Hg2+ replaced Co2+ nodes from ZIF-67 and formed a more stable precipitate with mIM. The experimental results showed that this new strategy was efficient. ZIF-67 exhibited Hg2+ adsorption capacity of 1740 mg/g, much higher than the known MOFs sorbents. mIMs is the reaction center and ZIF-67 can improve its utilization. The sample color faded from purple to white due to the loss of cobalt ion. It is a great feature of ZIF-67 that allows users to judge whether the sorbent is deactivated intuitively. ZIF-67 can be sustainable recycled by adding organic ligands to the solution after treatment due to its simple synthesis method at room temperature. It's a high-efficient and sustainable sorbent for Hg2+ separation from wastewater.
Assuntos
Mercúrio , Estruturas Metalorgânicas , Poluentes Químicos da Água , Íons , Mercúrio/química , Estruturas Metalorgânicas/química , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
Growing evidence indicates that organic aerosol (OA) is a significant absorber of solar radiation. Such absorptive OA is known as "brown carbon" (BrC). However, a formal analytical method for BrC is currently lacking although several methods have been applied to determine its absorption properties. Reported imaginary refractive index (kOA) values from various combustion sources span 2 orders of magnitude. Measurement methods are an important factor affecting this kOA variation. In this work, isolated OA from wood pyrolysis was used to compare four methods to determine absorbing properties of OA. The generated aerosol was lognormally distributed, spherical, and nearly pure organic matter. Optical closure was considered as the reference method. kOA calculated from the extract bulk light absorbance measurement was comparable to that determined by optical closure. kOA and mass absorption cross section obtained by online and offline filter-based transmission measurements were similar, but 3.5 to 5.0 times greater than those determined by optical closure. Absorption Ångström Exponents determined by the four methods were comparable and ranged from 6.1 to 6.8. A clear-sky radiative transfer model implied that using the optical parameters derived from different methods in the full climate model could produce different radiative impacts of primary OA emissions.
Assuntos
Pirólise , Madeira , Aerossóis , Carbono , ClimaRESUMO
The spectral dependence of aerosol light absorption (αabs) and single-scattering albedo-[ω, defined as the ratio of the scattering (αscat) and extinction coefficients (αext = αabs + αscat)]-has proven effective in classifying dominant aerosol types. It is also helpful in understanding aerosol sources, transformation, climate and environmental effects, testing aerosol models, and improving the retrieval accuracy of satellite and remote sensing data. Despite the significant progress that has been made with measurement of light absorption and ω, many of the reported instruments either operate at a fixed wavelength or can only measure a single optical parameter. Quantitative multi-parameter wavelength-dependent measurement remains a challenge. In this work, a three-wavelength cavity-enhanced albedometer was developed. The albedometer can measure multiple optical parameters, αext, αscat, αabs, and ω, at λ = 365, 532, and 660 nm, in real time. The instrument's performance was evaluated using four different type laboratory generated aerosols, including polystyrene latex spheres (PSL, non-absorbing); ammonium sulfate (AS, non-absorbing); suwannee river fulvic acid (SRFA, slightly absorbing; a proxy for light absorbing organic aerosol); and nigrosin (strongly absorbing).
RESUMO
This article describes the development and field application of a portable broadband cavity enhanced spectrometer (BBCES) operating in the spectral range of 440-480 nm for sensitive, real-time, in situ measurement of ambient glyoxal (CHOCHO) and nitrogen dioxide (NO2). The instrument utilized a custom cage system in which the same SMA collimators were used in the transmitter and receiver units for coupling the LED light into the cavity and collecting the light transmitted through the cavity. This configuration realised a compact and stable optical system that could be easily aligned. The dimensions and mass of the optical layer were 676 × 74 × 86 mm3 and 4.5 kg, respectively. The cavity base length was about 42 cm. The mirror reflectivity at λ = 460 nm was determined to be 0.9998, giving an effective absorption pathlength of 2.26 km. The demonstrated measurement precisions (1σ) over 60 s were 28 and 50 pptv for CHOCHO and NO2 and the respective accuracies were 5% and 4%. By applying a Kalman adaptive filter to the retrieved concentrations, the measurement precisions of CHOCHO and NO2 were improved to 8 pptv and 40 pptv in 21 s.
RESUMO
Oil-paper insulation is widely used as a reliable composite insulation system in power transformers. The dielectric property of oil insulation plays an important role in the reliable operation of power equipment. To recognize the charge transfer process in composite insulation, the mobility of the charge in aged insulating oil is studied. However, few studies have been conducted on the microscopic mechanism of charge transport phenomena at the molecular level. In this research, we have studied the molecular electronic structure and the distribution of holes and electrons in the insulating oil by first-principles calculation. By combining with Marcus theory, the corresponding electron coupling energy, reorganization energy, and free energy are obtained. The corresponding charge hopping model is chosen by the parameter relation, and the hopping rate is calculated. At last, the mobility of holes and electrons in insulating oil within the insulation is simulated by the Monte Carlo method. Other possible charge migration methods are also studied and discussed for the comparison. It is observed that the transfer integral of electrons is 2 orders of magnitude larger than that of holes, which is mostly due to the localization of lowest unoccupied molecular orbitals (LUMO). The hole and charge transfers accord with Marcus hopping, the adiabatic charge transfer model, and the charge hopping rate is obtained. The actual free energy action under an external electric field is obtained by calculating polarizability and permittivity. Monte Carlo simulation is used to obtain the charge transfer image and mobility under an actual electric field. Possible types of traps and mobility of ions and clusters in the insulating oil are also studied.
RESUMO
Recently, extreme wildfires occur frequently around the world and emit substantial brown carbon (BrC) into the atmosphere, whereas the molecular compositions and photochemical evolution of BrC remain poorly understood. In this work, primary smoke aerosols were generated from wood smoldering, and secondary smoke aerosols were formed by the OH radical photooxidation in an oxidation flow reactor, where both primary and secondary smoke samples were collected on filters. After solvent extraction of filter samples, the molecular composition of dissolved organic carbon (DOC) was determined by Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). The molecular composition of dissolved BrC was obtained based on the constraints of DOC formulae. The proportion of dissolved BrC fractions accounted for approximately 1/3-1/2 molecular formulae of DOC. The molecular characteristics of dissolved BrC showed higher levels of carbon oxidation state, double bond equivalents, and modified aromaticity index than those of DOC, indicating that dissolved BrC fractions were a class of organic structures with relatively higher oxidation state, unsaturated and aromatic degree in DOC fractions. The comparative analysis suggested that aliphatic and olefinic structures dominated DOC fractions (contributing to 70.1%-76.9%), while olefinic, aromatic, and condensed aromatic structures dominated dissolved BrC fractions (contributing to 97.5%-99.9%). It is worth noting that dissolved BrC fractions only contained carboxylic-rich alicyclic molecules (CRAMs)-like structures, unsaturated hydrocarbons, aromatic structures, and highly oxygenated compounds. CRAMs-like structures were the most abundant species in both DOC and dissolved BrC fractions. Nevertheless, the specific molecular characteristics for DOC and dissolved BrC fractions varied with subgroups after aging. The results highlight the similarities and differences in the molecular compositions and characteristics of DOC and dissolved BrC fractions with aging. This work will provide insights into understanding the molecular composition of DOC and dissolved BrC in smoke.
Assuntos
Aerossóis , Carbono , Fumaça , Madeira , Carbono/análise , Carbono/química , Fumaça/análise , Madeira/química , Aerossóis/análise , Aerossóis/química , Oxirredução , Incêndios Florestais , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Processos FotoquímicosRESUMO
AIMS: Ubiquitin specific peptidase 5 (USP5), a member of deubiquitinating enzymes, has garnered significant attention for its crucial role in cancer progression. This study aims to explore the role of USP5 and its potential molecular mechanisms in cholangiocarcinoma (CCA). MAIN METHODS: To explore the effect of USP5 on CCA, gain-of-function and loss-of-function assays were conducted in human CCA cell lines RBE and HCCC9810. The CCK8, colony-forming assay, EDU, flow cytometry, transwell assay and xenografts were used to assess cell proliferation, migration and tumorigenesis. Western blot and immunohistochemistry were performed to measure the expression of related proteins. Immunoprecipitation and immunofluorescence were applied to identify the interaction between USP5 and Y box-binding protein 1 (YBX1). Ubiquitination assays and cycloheximide chase assays were carried out to confirm the effect of USP5 on YBX1. KEY FINDINGS: We found USP5 is highly expressed in CCA tissues, and upregulated USP5 is required for the cancer progression. Knockdown of USP5 inhibited cell proliferation, migration and epithelial-mesenchymal transition (EMT) in vitro, along with suppressed xenograft tumor growth and metastasis in vivo. Mechanistically, USP5 could interact with YBX1 and stabilize YBX1 by deubiquitination in CCA cells. Additionally, silencing of USP5 hindered the phosphorylation of YBX1 at serine 102 and its subsequent translocation to the nucleus. Notably, the effect induced by USP5 overexpression in CCA cells was reversed by YBX1 silencing. SIGNIFICANCE: Our findings reveal that USP5 is required for cell proliferation, migration and EMT in CCA by stabilizing YBX1, suggesting USP5-YBX1 axis as a promising therapeutic target for CCA.
Assuntos
Neoplasias dos Ductos Biliares , Movimento Celular , Proliferação de Células , Colangiocarcinoma , Progressão da Doença , Transição Epitelial-Mesenquimal , Camundongos Nus , Proteína 1 de Ligação a Y-Box , Humanos , Colangiocarcinoma/patologia , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/genética , Animais , Camundongos , Linhagem Celular Tumoral , Proteína 1 de Ligação a Y-Box/metabolismo , Proteína 1 de Ligação a Y-Box/genética , Ubiquitinação , Camundongos Endogâmicos BALB C , Masculino , Endopeptidases/metabolismo , Endopeptidases/genética , Regulação Neoplásica da Expressão Gênica , FemininoRESUMO
Two-photon photodynamic therapy (TP-PDT) offers an innovative approach to cancer treatment that utilizes near-infrared light to activate photosensitizers and generate reactive oxygen species (ROS) for targeted cancer cell elimination. TiO2-CUR-Sofast (TCS), which uses TiO2 nanoparticles and Sofast cationic polymer to modify curcumin (CUR), has demonstrated potential as a photosensitizer under visible light irradiation, addressing the limitations of CUR's narrow spectral range and low bioavailability. This study explores the utility of the two-photon technique to activate TCS within the infrared spectrum, aiming to enhance ROS production and penetration depth compared to traditional CUR. TCS exhibits a significantly higher ROS production at 900â¯nm excitation wavelength, approximately 6-7 times that of CUR, signifying a substantial increase in efficiency. In TP-PDT, TCS showed significant phototoxicity against HeLa and T24 cell lines compared to CUR. Furthermore, TCS's photodynamic efficacy is further confirmed by cell apoptosis and necrosis studies, where approximately 89â¯% of cells treated with TCS under 900â¯nm light irradiation were observed in an apoptosis/necrosis state. And the TP-PDT effect in deep tissue was simulated using pig skin. It shows that the two-photon excitation has a significant penetration depth advantage over the single-photon excitation. These results indicate that the two-photon PDT scheme of TCS has greater potential than the single-photon PDT scheme in the treatment of cancer, and provides an experimental foundation for the effective treatment of deep lesions.
RESUMO
Pluripotent stem cell-derived small extracellular vesicles (PSC-sEVs) have demonstrated great clinical translational potential in multiple aging-related degenerative diseases. Characterizing the PSC-sEVs is crucial for their clinical applications. However, the specific marker pattern of PSC-sEVs remains unknown. Here, the sEVs derived from two typical types of PSCs including induced pluripotent stem cells (iPSC-sEVs) and embryonic stem cells (ESC-sEVs) were analysed using proteomic analysis by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and surface marker phenotyping analysis by nanoparticle flow cytometry (NanoFCM). A group of pluripotency-related proteins were found to be enriched in PSC-sEVs by LC-MS/MS and then validated by Western Blot analysis. To investigate whether these proteins were specifically expressed in PSC-sEVs, sEVs derived from seven types of non-PSCs (non-PSC-sEVs) were adopted for analysis. The results showed that PODXL, OCT4, Dnmt3a, and LIN28A were specifically enriched in PSC-sEVs but not in non-PSC-sEVs. Then, commonly used surface antigens for PSC identification (SSEA4, Tra-1-60 and Tra-1-81) and PODXL were gauged at single-particle resolution by NanoFCM for surface marker identification. The results showed that the positive rates of PODXL (>50%) and SSEA4 (>70%) in PSC-sEVs were much higher than those in non-PSC-sEVs (<10%). These results were further verified with samples purified by density gradient ultracentrifugation. Taken together, this study for the first time identified a cohort of specific markers for PSC-sEVs, among which PODXL, OCT4, Dnmt3a and LIN28A can be detected with Western Blot analysis, and PODXL and SSEA4 can be detected with NanoFCM analysis. The application of these specific markers for PSC-sEVs identification may advance the clinical translation of PSCs-sEVs.
Assuntos
Vesículas Extracelulares , Células-Tronco Pluripotentes , Humanos , Proteômica , Cromatografia Líquida , Espectrometria de Massas em Tandem , Células-Tronco Pluripotentes/metabolismoRESUMO
The crystal structure has a great influence on the dielectric and piezoelectric performance of poly(vinylidene fluoride) (PVDF). In this work, we prepared PVDF films with two typical crystalline phases (α and ß). In situ Kelvin probe force microscopy (KPFM) and Piezoelectric force microscopy (PFM) were employed to investigate the responses of different PVDF crystalline phases to charge mobility, polarization, and piezoelectric properties. We used a homemade Kelvin probe force microscope (KPFM) to inject charges into the two crystalline phases to investigate the differences in the response of different crystalline phases of PVDF to electrical excitation on a microscopic scale. It was found that the α-phase has a lower charge injection barrier and is more susceptible to charge injection and that the α-phase is accompanied by a faster charge dissipation rate, which makes it easier to accumulate charge at the interface between the α-phase and ß-phase PVDF. Moreover, the PFM polarization manipulation showed no change in the amplitude and phase diagram of the α-phase under ±10 V bias. In contrast, the ß-phase showed a clear polarization reversal phenomenon and a significant increase in piezoelectric amplitude, which is consistent with its polar intrinsic properties. This study provides valuable insights into the multiphase contributions and a reference for designing advanced PVDF dielectrics.
RESUMO
Indoor photovoltaics (IPVs) have attracted increasing attention for sustainably powering Internet of Things (IoT) electronics. Sb2S3 is a promising IPV candidate material with a bandgap of ~1.75 eV, which is near the optimal value for indoor energy harvesting. However, the performance of Sb2S3 solar cells is limited by nonradiative recombination, which is dependent on the quality of the absorber films. Additive engineering is an effective strategy to fine tune the properties of solution-processed films. This work shows that the addition of monoethanolamine (MEA) into the precursor solution allows the nucleation and growth of Sb2S3 films to be controlled, enabling the deposition of high-quality Sb2S3 absorbers with reduced grain boundary density, optimized band positions, and increased carrier concentration. Complemented with computations, it is revealed that the incorporation of MEA leads to a more efficient and energetically favorable deposition for enhanced heterogeneous nucleation on the substrate, which increases the grain size and accelerates the deposition rate of Sb2S3 films. Due to suppressed carrier recombination and improved charge-carrier transport in Sb2S3 absorber films, the MEA-modulated Sb2S3 solar cell yields a power conversion efficiency (PCE) of 7.22% under AM1.5 G illumination, and an IPV PCE of 17.55% under 1000 lux white light emitting diode (WLED) illumination, which is the highest yet reported for Sb2S3 IPVs. Furthermore, we construct high performance large-area Sb2S3 IPV minimodules to power IoT wireless sensors, and realize the long-term continuous recording of environmental parameters under WLED illumination in an office. This work highlights the great prospect of Sb2S3 photovoltaics for indoor energy harvesting.
RESUMO
Spike architecture influences both grain weight and grain number per spike, which are the two major components of grain yield in bread wheat (Triticum aestivum L.). However, the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits. Here, we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat. We identified 170 loci that are responsible for variations in spike length, spikelet number per spike, and grain number per spike through genome-wide association study and meta-QTL analyses. We constructed gene regulatory networks for young inflorescences at the double ridge stage and the floret primordium stage, in which the spikelet meristem and the floret meristem are predominant, respectively, by integrating transcriptome, histone modification, chromatin accessibility, eQTL, and protein-protein interactome data. From these networks, we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits. The functions of TaZF-B1, VRT-B2, and TaSPL15-A/D in establishment of wheat spike architecture were verified. This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.
Assuntos
Redes Reguladoras de Genes , Variação Genética , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Triticum , Triticum/genética , Triticum/crescimento & desenvolvimento , Locos de Características Quantitativas/genética , Regulação da Expressão Gênica de Plantas , FenótipoRESUMO
A 6-amidinotetrahydroquinoline screening hit was driven to a structurally novel, potent, and selective FVIIa inhibitor through a combination of library synthesis and rational design. An efficient gram-scale synthesis of the active enantiomer BMS-593214 was developed, which required significant optimization of the key Povarov annulation. Importantly, BMS-593214 showed antithrombotic efficacy in a rabbit arterial thrombosis model. A crystal structure of BMS-593214 bound to FVIIa highlights key contacts with Asp 189, Lys 192, and the S2 pocket.
Assuntos
Benzoatos/química , Benzoatos/farmacologia , Fator VIIa/antagonistas & inibidores , Fator VIIa/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Trombose/prevenção & controle , Animais , Benzoatos/síntese química , Modelos Animais de Doenças , Compostos Heterocíclicos de 4 ou mais Anéis/síntese química , Coelhos , Relação Estrutura-AtividadeRESUMO
The reliance of modern society on indoor environments increasing has made them crucial sites for human exposure to microbes. Extensive research has identified ecological drivers that influence indoor microbial assemblages. However, few studies have examined the dispersion of microbes in different locations of identical indoor environments. In this study, we employed PacBio Sequel full-length amplicon sequencing to examine the distribution of microbes at distinct locations in a single home and to identify the potential pathogens and microbial functions. Microbial communities differed considerably among the indoor sampling sites (P < 0.05). In addition, bacterial diversity was influenced by human activities and contact with the external environment at different sites, whereas fungal diversity did not significantly differ among the sites. Potential pathogens, including bacteria and fungi, were significantly enriched on the door handle (P < 0.05), suggesting that door handles may be hotpots for potential pathogens in the household. A high proportion of fungal allergens (34.37 %-56.50 %), which can cause skin diseases and asthma, were observed. Co-occurrence network analysis revealed the essential ecological role of microbial interactions in the development of a healthy immune system. Overall, we revealed the differences in microbial communities at different sampling sites within a single indoor environment, highlighting the distribution of potential pathogens and ecological functions of microbes, and providing a new perspective and information for assessing indoor health from a microbiological viewpoint.