ABSTRACT
Ion specificity is crucial for developing fluorescence probes. Using a recently reported optical sensor (BDA-1) of Zn2+ as a representative, we carried out extensive quantum chemical calculations on its photophysical properties using density function theory. According to the calculated optimized geometries, excitation energies and transition oscillator strengths, the weak fluorescence of BDA-1 observed in experiments is attributed to the suppression of fluorescence emission by efficient internal conversion, rather than the previously proposed photoinduced electron transfer (PET) mechanism. With the addition of Zn2+ or Cd2+ ions, the tetradentate chelates [M:BDA-1-H+]+ (M=Zn, Cd) are produced. According to frontier molecular orbital and interfragment charge transfer analyses of these complexes, PET is preferentially confirmed to occur upon photo-excitation. Notably, as one coordination bond in the excited [Cd:BDA-1-H+]+ complex is significantly weakened in comparison to that of [Zn:BDA-1-H+]+, their molecular orbital compositions in the S1 state are completely different. As a result, absorption and radiation transitions of [Zn:BDA-1-H+]+ both have considerable oscillator strength, while fluorescence radiation from the excited [Cd:BDA-1-H+]+ is doubly suppressed. This difference causes that the fluorescence intensity of BDA-1 is sensitive to the addition of metal ions, and exhibits the zinc ion-specificity.
ABSTRACT
The catalytic transformation of CO2 into valuable products has garnered wide interest owing to both economic and environmental benefits, in which the chemical fixation of CO2 into carbonate structures represents a crucial step that occurs on the adsorbed catalyst surfaces. Transition metal oxides with acidic and basic active sites have exhibited potential in promoting the carbonation of weakly bound CO2 molecules. Here, the interactions between CO2 molecules and the Sc3O4+ cation in the gas phase are investigated by using infrared photodissociation spectroscopy in conjunction with quantum chemical calculations. Both end-on and various carbonate-containing configurations, including center and bridge carbonate structures, have been theoretically identified for the CO2-coordinated ion-molecule complexes. Based on the comparison between the experimental spectra and simulated spectra of low-lying isomers in the CO2 antisymmetric stretching vibrational frequency region, isomers characterized by a bridge carbonate core structure are demonstrated to be the major contributors to the observed spectra. Examination of potential energy surfaces reveals lower energy barriers and simpler reaction routes for the conversion of molecularly bound CO2 into a bridge carbonate moiety, providing reasonable explanations for their prevalence in the experiments.
ABSTRACT
In this contribution, we report on the visualization of 12-crown-4 molecular diffusion behavior within a single-crystal particle of covalent organic framework-300 (COF-300) using operando dark-field optical microscopy. The diffusion area and front of 12-crown-4 are directly tracked in real time, offering key information for quantifying the diffusion coefficient (D). The direction of the diffusion and variation of D reveal intraparticle and interparticle heterogeneity. Notably, an unexpected hydration-accelerated diffusion process of 12-crown-4 within the pore channels of COF-300 is captured, in which a relatively low concentration of 12-crown-4 aqueous solution induces a fast diffusion, whereas the pure 12-crown-4 liquid cannot access the framework. The observed acceleration diffusion is demonstrated to arise from the hydrogen-bonding interactions between surface water molecules of hydrated 12-crown-4 and the imine groups of COF-300. These findings expand the mechanistic understanding of the noncovalent interactions between COFs and crown ethers (CEs), which will help to design and prepare CE-based COFs with improved performance.
ABSTRACT
Carbon dioxide (CO2) adsorption is a critical step to curbing carbon emissions from fossil fuel combustion. Among various options, transition metal oxides have received extensive attention as promising CO2 adsorbents due to their affordability and sustainability for large-scale use. Here, the nature of binding interactions between CO2 molecules and cationic scandium oxides of different sizes, i.e., ScO+, Sc2O2+, and Sc3O4+, is investigated by mass-selective infrared photodissociation spectroscopy combined with quantum chemical calculations. The well-accepted electrostatic considerations failed to provide explanations for the trend in the binding strengths and variations in the binding orientations between CO2 and metal sites of cationic scandium oxides. The importance of orbital interactions in the driving forces for CO2 adsorption on cationic scandium oxides was revealed by energy decomposition analyses. A molecular surface property, known as the local electron attachment energy, is introduced to elucidate the binding affinity and orientation-specific reactivity of cationic scandium oxides upon the CO2 attachment. This study not only reveals the governing factor in the binding behaviors of CO2 adsorption on cationic scandium oxides but also serves as an archetype for predicting and rationalizing favorable binding sites and orientations in extended surface-adsorbate systems.
ABSTRACT
Sequentially timed all-optical mapping photography is one of the main emerging ultra-fast detection technologies that can be widely applicable to ultra-fast detection at the picosecond level in fields such as materials and life sciences. We propose a new optical structure for an all-optical spatial mapping module that can control the optical field of two-dimensional imaging while improving spectral resolution and detector sensor utilization. The model of optical parameters based on geometrical optics theory for the given structure has been established, and the theoretical analysis of the inter-frame energy crosstalk caused by incident beam spot width, chromatic aberration, and main errors of the periscope array has been conducted. The optical design of the two-dimensional (2D) all-optical spatial mapping module was finally completed using ZEMAX OpticStudio 2018 software. The results show that our optical module can realize targets of 16 frames and 1.25 nm spectral resolution.
ABSTRACT
The global circulation of clade 2.3.4.4b H5Ny highly pathogenic avian influenza viruses (HPAIVs) in poultry and wild birds, increasing mammal infections, continues to pose a public health threat and may even form a pandemic. An efficacious vaccine against H5Ny HPAIVs is crucial for emergency use and pandemic preparedness. In this study, we developed a parainfluenza virus 5 (PIV5)-based vaccine candidate expressing hemagglutinin (HA) protein of clade 2.3.4.4b H5 HPAIV, termed rPIV5-H5, and evaluated its safety and efficacy in mice and ferrets. Our results demonstrated that intranasal immunization with a single dose of rPIV5-H5 could stimulate H5-specific antibody responses, moreover, a prime-boost regimen using rPIV5-H5 stimulated robust humoral, cellular, and mucosal immune responses in mice. Challenge study showed that rPIV5-H5 prime-boost regimen provided sterile immunity against lethal clade 2.3.4.4b H5N1 virus infection in mice and ferrets. Notably, rPIV5-H5 prime-boost regimen provided protection in mice against challenge with lethal doses of heterologous clades 2.2, 2.3.2, and 2.3.4 H5N1, and clade 2.3.4.4h H5N6 viruses. These results revealed that rPIV5-H5 can elicit protective immunity against a diverse clade of highly pathogenic H5Ny virus infection in mammals, highlighting the potential of rPIV5-H5 as a pan-H5 influenza vaccine candidate for emergency use.IMPORTANCEClade 2.3.4.4b H5Ny highly pathogenic avian influenza viruses (HPAIVs) have been widely circulating in wild birds and domestic poultry all over the world, leading to infections in mammals, including humans. Here, we developed a recombinant PIV5-vectored vaccine candidate expressing the HA protein of clade 2.3.4.4b H5 virus. Intranasal immunization with rPIV5-H5 in mice induced airway mucosal IgA responses, high levels of antibodies, and robust T-cell responses. Importantly, rPIV5-H5 conferred complete protection in mice and ferrets against clade 2.3.4.4b H5N1 virus challenge, the protective immunity was extended against heterologous H5Ny viruses. Taken together, our data demonstrate that rPIV5-H5 is a promising vaccine candidate against diverse H5Ny influenza viruses in mammals.
Subject(s)
Influenza A Virus, H5N1 Subtype , Influenza A Virus, H5N6 Subtype , Influenza Vaccines , Orthomyxoviridae Infections , Parainfluenza Virus 5 , Animals , Humans , Mice , Ferrets/immunology , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Immunity, Cellular , Immunity, Humoral , Immunity, Mucosal , Influenza A Virus, H5N1 Subtype/chemistry , Influenza A Virus, H5N1 Subtype/classification , Influenza A Virus, H5N1 Subtype/genetics , Influenza A Virus, H5N1 Subtype/immunology , Influenza A Virus, H5N6 Subtype/chemistry , Influenza A Virus, H5N6 Subtype/classification , Influenza A Virus, H5N6 Subtype/genetics , Influenza A Virus, H5N6 Subtype/immunology , Influenza in Birds/immunology , Influenza in Birds/prevention & control , Influenza in Birds/transmission , Influenza in Birds/virology , Influenza Vaccines/administration & dosage , Influenza Vaccines/adverse effects , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/prevention & control , Orthomyxoviridae Infections/transmission , Orthomyxoviridae Infections/virology , Pandemic Preparedness/methods , Parainfluenza Virus 5/genetics , Parainfluenza Virus 5/immunology , Parainfluenza Virus 5/metabolism , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/adverse effects , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Administration, Intranasal , Poultry/virology , Immunoglobulin A/immunology , T-Lymphocytes/immunologyABSTRACT
Swine influenza viruses pose ongoing threat to pork industry throughout the world. In 2023, fattening pigs from a swine farm in Inner Mongolia of China experienced influenza-like symptoms. Co-infection of influenza A virus with Pasteurella multocida was diagnosed in lung tissues of diseased pigs and a genotype 4 (G4) Eurasian avian-like (EA) H1N1 virus was isolated, which was named as A/swine/Neimenggu/0326/2023. We demonstrated the virus preferentially bound human-like SAα2,6Gal receptor. It was noteworthy that the virus possessed multiple genetic markers for mammalian adaptation in the internal genes. Animal studies showed that compared with genotype 1 (G1) EA H1N1 virus and early prevalent G4 EA H1N1 virus, A/swine/Neimenggu/0326/2023 virus exhibited increased virus shedding, enhanced replication in lungs, and caused more severe lung lesions in pigs. These findings indicate that the G4 EA H1N1 virus poses increased threat to pork industry, controlling the prevailing viruses in pigs should be promptly implemented.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A virus , Influenza, Human , Orthomyxoviridae Infections , Pneumonia , Swine Diseases , Swine , Humans , Animals , Influenza A Virus, H1N1 Subtype/genetics , Influenza A virus/genetics , Genotype , Birds , China/epidemiology , Orthomyxoviridae Infections/veterinary , Reassortant Viruses/genetics , MammalsABSTRACT
In China, six species of Statherotmantis Diakonoff, 1973 were previously recorded. In the present study, four other species were recognized using morphology and DNA barcording analysis. Among these, three of which, S. miniscula sp. n., S. calva sp. n., and S. longiuscula sp. n., are described as new. In addition, one species, S. laetana Kuznetzov, 1988, is a new record for China. Adults and genitalia are illustrated, and keys to identify the Chinese species of Statherotmantis are provided.
ABSTRACT
Bismuth-based metal-organic frameworks (Bi-MOFs) have emerged as important photocatalysts for pollutant degradation applications. Understanding the photocatalytic degradation mechanism is key to achieving technological advantage. Herein, we apply dark-field optical microscopy (DFM) to realize in situ multicolor imaging of the photocatalytic degradation process of permanganate (MnO4-) on single CAU-17 Bi-MOFs. Three reaction kinetic processes such as surface adsorption, photocatalytic reduction, and disproportionation are revealed by combining the time-lapsed DFM images with optical absorption spectra, indicating that the photocatalytic reduction of purple MnO4- first produces beige red MnO42- through a one-electron pathway, and then MnO42- disproportionates into yellow MnO2 on CAU-17. Meanwhile, we observe that the deposition of MnO2 cocatalysts enhances the surface adsorption reaction and the photocatalytic reduction of MnO4- to MnO42-. Unexpectedly, it is found that isopropanol as a typical hole scavenger can stabilize MnO42-, avoiding disproportionation and causing the alteration of the photocatalytic reaction pathway from a one-electron avenue to a three-electron (1 + 2) process for producing MnO2 on CAU-17. This research opens up the possibility of comprehensively tracking and understanding the photocatalytic degradation reaction at the single MOF particle level.
ABSTRACT
H3N8 avian influenza viruses (AIVs) in China caused two confirmed human infections in 2022, followed by a fatal case reported in 2023. H3N8 viruses are widespread in chicken flocks; however, the zoonotic features of H3N8 viruses are poorly understood. Here, we demonstrate that H3N8 viruses were able to infect and replicate efficiently in organotypic normal human bronchial epithelial (NHBE) cells and lung epithelial (Calu-3) cells. Human isolates of H3N8 virus were more virulent and caused severe pathology in mice and ferrets, relative to chicken isolates. Importantly, H3N8 virus isolated from a patient with severe pneumonia was transmissible between ferrets through respiratory droplets; it had acquired human-receptor-binding preference and amino acid substitution PB2-E627K necessary for airborne transmission. Human populations, even when vaccinated against human H3N2 virus, appear immunologically naive to emerging mammalian-adapted H3N8 AIVs and could be vulnerable to infection at epidemic or pandemic proportion.
Subject(s)
Influenza A Virus, H3N8 Subtype , Influenza, Human , Animals , Humans , Mice , Chickens , Ferrets , Influenza A Virus, H3N2 Subtype , Respiratory Aerosols and DropletsABSTRACT
Lipid droplets (LDs) are multifunctional organelles consisting of a central compartment of non-polar lipids shielded from the cytoplasm by a phospholipid monolayer. The excessive accumulation of LDs in cells is closely related to the development and progression of many diseases in humans and animals, such as liver-related and cardiovascular diseases. Thus, regulating the LDs size and abundance is necessary to maintain metabolic homeostasis. This study found that lipopolysaccharide (LPS) stimulation reduced the LDs content in the mouse liver. We tried to explain the possible molecular mechanisms at the broad protein and mRNA levels, finding that inhibition of the peroxisome proliferator-activated receptors (PPAR) signalling pathway by LPS may be a critical factor in reducing LDs content.
Subject(s)
Lipopolysaccharides , Peroxisome Proliferator-Activated Receptors , Humans , Animals , Mice , Lipopolysaccharides/pharmacology , Peroxisome Proliferator-Activated Receptors/genetics , Peroxisome Proliferator-Activated Receptors/metabolism , Lipid Droplets/metabolism , Transcriptome , Proteomics , Liver/metabolism , Lipid Metabolism/physiologyABSTRACT
Two new species of the genus Phaecadophora, P.dactylinasp. nov. and P.vascularissp. nov., are described from the southwest China. Photographs of the adults and the genitalia are provided. Keys to the species of the genus based on the male and female genitalia are given.
ABSTRACT
The thermochromic properties of hydrated metal halide perovskites (MHPs) are promising for applications in smart windows, solar cells, optical sensors, and information storage. Traditional ensemble characterization methods always study the averaged thermochromic activity, lacking the accurate structure-activity correlation. Here we utilize dark-field microscopy (DFM) to in situ image the thermochromic processes of single isolated hydrated hybrid perovskite (CH3NH3)4PbI6-xClx·2H2O (MA4PbI6-xClx·2H2O) microparticles. The thermal-induced dehydration transition is demonstrated to alter the color of single MA4PbI6-xClx·2H2O particles. Operando single-particle mapping results reveal the significant intra- and interparticle variations of thermochromic behaviors, yielding unexpected single or multistep multicolor thermochromic processes. These phenomena are confirmed to be governed by the crystallinity of single MA4PbI6-xClx·2H2O particles that results in distinct composition-dependent bandgaps and thermal decomposition pathways. The present work highlights the important role of single-particle imaging for resolving the intrinsic thermochromic characteristic of hydrated MHPs, therefore opening a way for rational design of stimuli-responsive materials.
ABSTRACT
Fungi are a hyper-diverse kingdom that contributes significantly to the regulation of the global carbon and nutrient cycle. However, our understanding of the distribution of fungal diversity is often hindered by a lack of data, especially on a large spatial scale. Open biodiversity data may provide a solution, but concerns about the potential spatial and temporal bias in species occurrence data arising from different observers and sampling protocols challenge their utility. The theory of species accumulation curves predicts that the cumulative number of species reaches an asymptote when the sampling effort is sufficiently large. Thus, we hypothesize that open biodiversity data could be used to reveal large-scale macrofungal diversity patterns if these datasets are accumulated long enough. Here, we tested our hypothesis with 50 years of macrofungal occurrence records in Norway and Sweden that were downloaded from the Global Biodiversity Information Facility (GBIF). We first grouped the data into five temporal subsamples with different cumulative sampling efforts (i.e., accumulation of data for 10, 20, 30, 40 and 50 years). We then predicted the macrofungal diversity and distribution at each subsample using the maximum entropy (MaxEnt) species distribution model. The results revealed that the cumulative number of macrofungal species stabilized into distinct distribution patterns with localized hotspots of predicted macrofungal diversity with sampling efforts greater than approximately 30 years. Our research demonstrates the utility and importance of the long-term accumulated open biodiversity data in studying macrofungal diversity and distribution at the national level.
ABSTRACT
Kennelia is a small genus in Tortricidae that is distributed in the Oriental and Palaearctic regions, and its taxonomic position within the subfamily Olethreutinae is controversial. For a comprehensive understanding of the genus, we sequenced the mitogenome of Kennelia xylinana, the type species of Kennelia, and Ancylis unculana, a species of Enarmoniini; analyzed the mitogenome characteristics of K. xylinana; and explored its phylogenetic position. Similar to other members of Lepidoptera, the mitogenome of K. xylinana is 15,762-bp long and consists of 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes, and a noncoding control region. In particular, we found a structure (TATAATTAATAA)11 in the middle of the AT-rich region. Based on the Bayesian inference and maximum likelihood analyses of the 13 PCGs of 40 tortricid species, representing 8 tribes of 2 subfamilies, K. xylinana was clustered with two members of Enarmoniini, A. unculana and Loboschiza koenigiana, and formed highly supported monophyly. The results indicate that Kennelia should be placed in the tribe Enarmoniini.
Subject(s)
Genome, Mitochondrial , Lepidoptera , Moths , Animals , Bayes Theorem , Phylogeny , RNA, TransferABSTRACT
The leaf roller, Clepsis pallidana (Fabricius, 1776) (Lepidoptera: Tortricidae), is an important pest of many crops in China. The circular genome is 15,679 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding AT-rich region. The base composition of the whole mitogenome is 41.2% A, 40.1% T, 11.1% C, and 7.7% G, which shows a strong AT bias. Phylogenetic analysis based on 13 PCGs showed that C. pallidana was closely related to Epiphyas postvittana and clustered within Archipini clade, which was consistent with the traditional classification.
ABSTRACT
T cells mediate adaptive immunity in diverse anatomic compartments through recognition of specific antigens via unique T cell receptor (TCR) structures. However, little is known about the spatial distribution of an organism's TCR repertoire. Here, using high-throughput TCR sequencing (TCRseq), we investigated the TCR repertoires of sixteen tissues in healthy C57B/L6 mice. We found that TCR repertoires generally classified into three categories (lymph nodes, non-lymph node tissues and small intestine) based on sequence similarity. Clonal distribution and diversity analyses showed that small intestine compartment had a more skewed repertoire as compared to lymph nodes and non-lymph node tissues. However, analysis of TRBV and TRBJ gene usage across tissue compartments, as well as comparison of CDR3 length distributions, showed no significant tissue-dependent differences. Interestingly, analysis of clonotype sharing between mice showed that although non-redundant public clonotypes were found more easily in lymph nodes, small intestinal CD4 + T cells harbored more abundant public clonotypes. These findings under healthy physiological conditions offer an important reference dataset, which may contribute to our ability to better manipulate T cell responses against infection and vaccination.
Subject(s)
Receptors, Antigen, T-Cell/immunology , T-Lymphocytes/immunology , Animals , Female , Mice , Mice, Inbred C57BLABSTRACT
Zeolitic imidazolate frameworks (ZIFs) are very useful as high-capacity iodine (I2) adsorbents. The adsorption performance is usually probed by measuring a statistical average property over an entire sample consisting of a large number of ZIF particles, leaving the interparticle heterogeneity information among individuals. Here we report a dark-field microscopy (DFM) method to visualize gaseous I2 adsorption on single ZIF-90 particles in situ and in real time. The adsorption of I2 is found to alter the scattering spectrum of ZIF-90 particles, inducing a distinct color change from bluewhite to yellow. According to correlating the adsorption amount of gaseous I2 with the change of B value from DFM images, we quantitatively image the adsorption process and estimate the related kinetic parameters at the single particle level. Single particle measurements clarify the large particle-to-particle heterogeneity in adsorption reactivity and significant adsorption activity improvement of ZIF-90 after introduction of linker defects, which provides a microscopic understanding of the structure-activity relationship. We further demonstrate the capacity of this strategy for studying gaseous I2 adsorption on single ZIF-91 particle as a derivative of ZIF-90 to illustrate the generality.
ABSTRACT
Imaging an adsorption reaction taking place at the single-particle level is a promising avenue for fundamentally understanding the adsorption mechanism. Here, we employ a dark-field microscopy (DFM) method for in situ imaging the adsorption process of I- on single Cu2O microparticles to reveal the acid activation mechanism. Using the time-lapsed DMF imaging, we find that a relatively strong acid is indispensable to trigger the adsorption reaction of I- on single Cu2O microparticle. A hollow microparticle with the increase in size is obtained after the adsorption reaction, causing the enhancement of the scattering intensity. Correlating the change of the scattering light intensity or particle size with adsorption capacity of I-, we quantitatively analyze the selective uptake, slightly heterogeneous adsorption behavior, pH/temperature-dependent adsorption capacity, and adsorption kinetics as well as isotherms of individual Cu2O microparticles for I-. Our observations demonstrate that the acid-initiated Kirkendall effect is responsible for the high-reaction activity of single Cu2O microparticles for adsorption of I- in the acidic environment, through breaking the unfavorable lattice energy between Cu2O and CuI as well as generating high-active hollow intermediate microparticle.
Subject(s)
Iodides , Adsorption , Kinetics , Particle SizeABSTRACT
The Berthelot reaction is a classic method for detection of ammonium (NH4+) and atmospheric ammonia (NH3) by using salicylic acid (SA) as the chromogenic substrate. However, there lacks a method for improving the activity of the Berthelot reaction to enhance the analytical performance for detection of NH4+ and NH3. Here, five SA analogues with electron-withdrawing groups (-F) and electron-donating groups (-CH3 and -OCH3) at different positions of the aromatic ring have been chosen as the alternative to SA for Berthelot reaction. Among these analogues, 4-methoxysalicylic acid (4-OCH3-SA) shows the best colorimetric response and color change at a NH4+ concentration of 30 µM, and the sensitivity of 4-OCH3-SA-based colorimetric assay for NH4+ increases 1.75-fold compared with that of SA-based colorimetric method. This enhancement effect is attributed to the strong electron-donating property of 4-OCH3 group, activating the two-step electrophilic aromatic substitution reaction in the Berthelot reaction. Additionally, visual and sensitive detection of NH3 is realized, along with a low limit of detection down to 0.037 ppm. Furthermore, we demonstrate that this assay is reliable and practical for detection of NH4+ and NH3 in real water and air samples with good accuracy.