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Strigolactones (SLs) constitute a class of plant hormones that regulate many aspects of plant development, including repressing tillering in rice (Oryza sativa). However, how SL pathways are regulated is still poorly understood. Here, we describe a rice mutant dwarf and high tillering1 (dht1), which exhibits pleiotropic phenotypes (such as dwarfism and increased tiller numbers) similar to those of mutants defective in SL signaling. We show that DHT1 encodes a monocotyledon-specific hnRNP-like protein that acts as a previously unrecognized intron splicing factor for many precursor mRNAs (pre-mRNAs), including for the SL receptor gene D14. We find that the dht1 (DHT1I232F) mutant protein is impaired in its stability and RNA binding activity, causing defective splicing of D14 pre-mRNA and reduced D14 expression, and consequently leading to the SL signaling-defective phenotypes. Overall, our findings deepen our understanding of the functional diversification of hnRNP-like proteins and establish a connection between posttranscriptional splicing and SL signaling in the regulation of plant development.

A novel electrochemical reconstruction strategy enables the best seawater electrolysis performance.

Hydrostatic pressure has been commonly applied to tune broadband light emissions from self-trapped excitons (STE) in perovskites for producing white light and study of basic electron-phonon interactions. However, a general theory is still lacking to understand pressure-driven evolution of STE emissions. In this work we first identify a theoretical model that predicts the effect of hydrostatic pressure on STE emission spectrum, we then report the observation of extremely broadband photoluminescence emission and its wide pressure spectral tuning in 2D indirect bandgap CsPb2Br5 crystals. An excellent agreement is found between the theory and experiment on the peculiar experimental observation of STE emission with a nearly constant spectral bandwidth but linearly increasing energy with pressure below 2 GPa. Further analysis by the theory and experiment under higher pressure reveals that two types of STE are involved and respond differently to external pressure. We subsequently survey published STE emissions and discovered that most of them show a spectral blue-shift under pressure, as predicted by the theory. The identification of an appropriate theoretical model and its application to STE emission through the coordinate configuration diagram paves the way for engineering the STE emission and basic understanding of electron-phonon interaction.

Monitors, televisions, and smartphones have been revolutionized by the invention of InGaN-based LED backlighting. Yet, regular exposure to the bright blue light emitted by these screens can lead to mood disorders and insomnia. Switching to a "human-centric" display that uses a violet-emitting LED chip and a trichromatic phosphor blend is one materials chemistry solution for this problem. The challenge is finding a blue-emitting phosphor with a sufficiently small Stokes’ shift to down-convert the violet LED light. This study reports a new oxynitride phosphor that meets this need. K3AlP3O9N:Eu2+ exhibits a narrow (45 nm, 2206 cm-1), thermally robust, and efficient blue photoluminescence upon violet excitation. Computational modeling and photoluminescence spectroscopy revealed that a rare combination of preferential excitation and site-selective quenching produce the desired optical properties. Combining K3AlP3O9N:Eu2+ with red- and green-emitting phosphors and a violet LED covers 10% more of the color gamut than a commercial tablet while simultaneously mitigating blue light exposure en route to next-generation, human-centric displays.

In this work we introduce a new series of ratiometric oxygen sensors for hypoxic environments based on phosphorescent cyclometalated iridium centers partnered with organic coumarin fluorophores. Three different cyclometalating ligands and two different pyridyl-containing coumarin types were used to prepare six target complexes with tunable excited-state energies. Three of the complexes display dual emission, with fluorescence arising from the coumarin ligand, and phosphorescence from either the cyclometalated iridium center or the coumarin. These dual-emitting complexes function as ratiometric oxygen sensors, with the phosphorescence is quenched under O₂ while fluorescence is unaffected. The use of blue-fluorescent coumarins results in good signal resolution between fluorescence and phosphorescenc. Moreover, the sensitivity and dynamic range, measured with Stern-Volmer analysis, can be tuned two orders of magnitude by virtue of our ability to synthetically control the triplet excited-state ordering. The complex with cyclometalated irdium 3MLCT phosphorescence operates under hyperoxic conditions, whereas the two complexes with coumarin-centered phosphorescence are sensitive to very low levels of O¬2 and function as hypoxic sensors.

Meta-analysis was used to study the validity of image-based dietary assessment(IBDA) in evaluating energy and macronutrients intake, and compared with three traditional method: weighed food record(WFR), 24-hour dietary recall(24-HDR) and double-labeled water(DLW).Studies were retrieved and collected from various databases including China National Knowledge Infrastructure(CNKI), WanFang Database, VIP Database, PubMed, Web of Science, Cochrane Library and Embase, screened according to the inclusion and exclusion criteria. After extracting the data, all the data were Meta-analyzed through RevMan 5.4.A total of 24 studies were included. Meta-analysis showed that, comparison of IBDA method and traditional method in energy intake assessment[MD=-54.71 kcal/d(95%CI-118.81-9.39), P=0.09], comparison of carbohydrate intake assessment[MD=-2.77 g(95%CI-8.86-3.31), P=0.37], comparison of protein intake assessment[MD=0.00 g(95%CI-2.09-2.09), Pgt;0.05], comparison of fat intake assessment[MD=0.10 g(95%CI-2.06-2.25), P=0.93], these differences were not statistically significant. Subgroup analysis showed that, IBDA method compared with the 24-hour dietary review method in protein intake(P=0.01), the difference was statistically significant. IBDA method overestimated protein intake by about 7.3% on average compared with the 24-hour dietary review method.There was no significant difference between IBDA method and traditional method in the assessment of energy and macronutrient intakes.

The production of long-chain hydrocarbons from CO2 and water using solar light is a big challenge for the catalysis society. Cobalt nanostructures have been reported to catalyze the production of C3-C15 alkanes in a cobalt-water-CO2 three-phase system under white light, yet the proposed photocatalytic mechanism still lacks evidence. In this work, cobalt micro- and nanostructures with different sizes and morphologies are used as model catalysts to reproduce this reaction. Despite different activity, selectivity and stability, the catalysts are found to follow the same reaction mechanism: a CO2 assisted galvanic replacement reaction to produce H2 followed by a thermal catalytic CO2 hydrogenation to produce alkanes; meanwhile, the Co catalysts are gradually but inevitably converted to CoCO3, leading to a slow deactivation. The low concentration of the in-situ formed H2 favors the growth of C2+ alkanes. The incident light drives the reaction by heating the catalyst, rather than providing plasmonic hot electrons for CO2 reduction.

Low-dimensional CsCu2I3 perovskite has recently attracted extensive attention for its unique structure and photoelectric properties. We demonstrate a detailed spectroscopy study of its self-trapped exciton emission and present a fundamental understanding of the electron-phonon interaction.

BackgroundStreptococcus suis is an emerging zoonotic agent. Its natural habitat is the tonsils, which are the main portals of S. suis entry into the bloodstream of pigs. The remarkable variability of the bacteria and complex pathogenic mechanisms make the development of a vaccine a difficult task.MethodFive conserved virulence factors involved in critical events of S. suis pathogenesis were combined and used as an intranasal vaccine (V5). The effect of V5 was investigated with intranasal and systemic challenge models.ResultsV5 induced antibody and T-cell responses at the mucosal site and systemically. The immunity promoted clearance of S. suis from the nasopharynx independent of S. suis serotypes and reduced lethality after systemic challenge with S. suis serotype 2. Moreover, mice that survived sepsis from intravenous infection developed meningitis, whereas none of these mice showed neuropathological symptoms after V5 receipt.ConclusionIntranasal immunization with multiple conserved virulence factors decreases S. suis colonization at the nasopharynx across serotypes and inhibits the dissemination of the bacteria in the host. The protective mucosal immunity effects would potentially reduce the S. suis reservoir and prevent S. suis disease in pigs.

In this work, CdO-Ag-ZnO nanocomposites with hierarchically porous structure and large surface area were successfully fabricated by solution combustion synthesis (SCS) method. Crystalline structure, morphology, surface chemical states and specific surface area were investigated by XRD, SEM, TEM, XPS and BET techniques, respectively. Sensors fabricated from CdO-Ag-ZnO nanocomposites were made based on indirect heating method, which showed superior sensing properties in detecting different concentration of volatile organic compounds (VOCs). In contrast with singular ZnO, gas-sensing experiment results reveal that the addition of CdO and Ag effectively decreases optimum working temperature, increases gas response value and shortens response and recovery time. What’s more, other gas-sensing properties including repeatability, sensitivity and long-term stability are also discussed in this research. Particularly, gas sensor based on 10 mol% CdO-Ag-ZnO shows modest gas-sensing performance to VOCs at the operating temperature of 200 °C, and its gas response values are 198.63, 156.07, 53.04, 64.23, 183.65 towards 100 ppm formaldehyde, ethanol, acetone, methanol and isopropanol, respectively, indicating it a promising candidate in detecting VOCs. Superior sensing property is mainly ascribed to large specific surface area, special porous surface morphology, unique combination of nanocomposites and good catalytic ability of metallic Ag.

Co(OH)2@FeCo2O4 nanocomposite was successfully synthesized via a facile one-step hydrothermal reaction without thermal treatment. The structure and chemical composition of as-synthesized Co(OH)2@FeCo2O4 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. The results show the FeCo2O4 nanosheets are covered with the Co(OH)2 nanoparticles and the BET show the nanocomposite possess the mesoporous structure with specific surface area and total pore volume are 93.071 m2 g−1 and 0.37 cm3 g−1, respectively. In addition, the electrochemical performances were investigated in a three-electrode system to evaluate the material. The as-synthesized Co(OH)2@FeCo2O4 nanocomposite exhibits a high specific capacitance of 1173.43 F g−1 at 1 A g−1 and remarkable cycling stability with 95.4% capacitance retention after 5000 cycles. The results show the higher capacitance and longer cycle performance, compared with the Co(OH)2 and FeCo2O4, respectively. This remarkable electrochemical performances were mainly due to mesoporous structure and the synergistic effect of Co(OH)2 and FeCo2O4. It means that this nanostructure Co(OH)2@FeCo2O4 synthesized by this simple and cost-effective method would have more hopeful prospects in energy storage applications.

Water-soluble rhodamine B assisted graphene quantum dots (RhB-GQDs) were synthesized by a facile one-pot hydrothermal method, using rhodamine B and ethylenediamine as nitrogen source. The as-synthesized RhB-GQDs have few layers configuration with an average size of 4.5 nm and good distribution. The fluorescence quenching approach was applied to the sensing of mercury ions in water. Rodamine B absorb on the surface of RhB-GQDs, and it can prevent RhB-GQDs from contacting with interfering cations. The presence of N atoms reduces the ability of interfering cations to form stable complex with carboxyl groups, and gives the RhB-GQDs good selectivity to mercury ions. In the case of low concentration, the fluorescence quenching efficiency of as-synthesized RhB-GQDs still has a good liner relationship with concentration. Due to the strong affinity of Hg2+ to amino and carboxyl on the surface of RhB-GQDs, the fluorescence of RhB-GQDs is quenched by nonradiative electron transfer between Hg2+ and the excited state of RhB-GQDs. Based on the fluorescence turn off process, the as-synthesized RhB-GQDs can be served as fluorescent platform for the sensitive and selective detection of Hg2+ with a detection limit of 0.16 nM.

Gas sensors based on noble metal/metal oxide are applied extensively, and show a relatively high response to carbon monoxide at inferior operating temperature. In this paper, a carbon monoxide sensor based on Pt decorated SnO2 nanoparticles is obtained by a hydrothermal method. Abundant characterization methods are used to analyze the structure, morphology, chemical state and specific surface area of the as-prepared compounds. The pure SnO2 sensor exhibits inferior operating temperature and low response for the detection of carbon monoxide. In contrast, the observed response of the sensor with the as-synthesized 1.5 mol% Pt decorated SnO2 is up to 610.45 at a low operating temperature of 80 °C, and the response value is about three times higher than that of SnO2 sensor. The significantly improved performance is thoroughly explained in terms of the adsorption–desorption mechanism, and the chemical sensitization and electronic sensitization of Pt.

Despite the unsettled mechanism of electricity generation from the continuous flow of liquids on a surface, the charge-discharge theory has been widely accepted for alternating current (AC) generation from a moving droplet. It has been recently extended to rationalize direct current (DC) generation across a droplet moving between two different materials. By designing a reconfigurable contact between a metal wire and a water droplet moving on graphene, we show that the charge-discharge theory cannot explain the reversal of current when water-metal interfaces switch from dynamic to static. All experiments can be described after we distinguish a dynamic from a static interface and generalize the photovoltaic-like effect to all dynamic junctions: excited electrons and holes in a moving interface will be separated and swept under the built-in electrical field, leading to a DC response. This generalized theory will lead to an understanding and the design of efficient electricity generation based on interfacial charge transfer.

A fatigue assessment approach for interior inclusion-FGA (fine granular area)-fisheye induced fracture was proposed through experimental investigation of very high cycle fatigue properties of two high-strength low-alloy steels. The rougher morphology of FGA reveals the rather distorted crack growth path and slow crack growth rate. A strength evaluation model related to defect size and fatigue life was developed, using which the predicted results are in agreement with the experimental results. Based on the modelling of micro-crack growth rate, the evaluated value can be less than the magnitude of one Burger’s vector, which reflects the discontinuous crack growth behavior within FGA.

Achieving efficient and durable nonprecious hydrogen evolution reaction (HER) catalysts for scaling up alkaline water/seawater electrolysis is desirable but remains a significant challenge. Here, a heterogeneous Ni-MoN catalyst consisting of Ni and MoN nanoparticles on amorphous MoN nanorods that can sustain large-current-density HER with outstanding performance is demonstrated. The hierarchical nanorod-nanoparticle structure, along with a large surface area and multidimensional boundaries/defects endows the catalyst with abundant active sites. The hydrophilic surface helps to achieve accelerated gas-release capabilities and is effective in preventing catalyst degradation during water electrolysis. Theoretical calculations further prove that the combination of Ni and MoN effectively modulates the electron redistribution at their interface and promotes the sluggish water-dissociation kinetics at the Mo sites. Consequently, this Ni-MoN catalyst requires low overpotentials of 61 and 136 mV to drive current densities of 100 and 1000 mA cm

The integration of highly luminescent CsPbBr

This paper describes the preparation with a sol-gel method as well as formaldehyde (HCHO) gas sensing properties of CdIn 2O4 nanoporous thin film . CdIn 2O4 nanoporous thin film was prepared using poly(ethylene-co-butylene)-b -poly(ethylene oxide) diblock copolymers as template. The film was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM), and x-ray photoelectron spectroscopy (XPS), respectively. The analyzed results indicate that the obtained thin film is highly crystalline and has pore-solid architectures after removal of the polymer template by calcination . As-prepared CdIn 2O4 nanoporous thin film was used directly as sensing device to investigate the sensing properties in HCHO atmosphere. The home-built CdIn2O4 nanoporous thin film gas-sensor shows high response, selectivity, and long-time stability toward HCHO gas at low operating temperature (100 °C), making the thin film not only interesting for sensor devices, but also for a number of related electrochemical applications.

ZnO nanocrystalline with a few nanometers in size were synthesized by a low-temperature solvothermal method from zinc acetate dihydrate (Zn(CH3COO)2·2H2O), potassium hydroxide (KOH) and ethanol (C2H5 OH). X ray diffraction (XRD), transmission electron microscopy (TEM) and X ray photoelectron spectroscopy (XPS) were used to characterize the structure, morphology, specific surface area and chemical state of the samples. The analyzed results indicate that the ZnO nanocrystalline with good dispersion are several nanometers in size about 10 nm. The ZnO nanocrystalline was used as sensing material to fabricate an indirect-heating structure sensor and its gas sensing properties are tested. At the optimal operating temperature (340 °C), its gas response toward 500 ppm n-butanol is 148.11 and the response and recovery time are 20 and 8 s, respectively. The test results show that the sensitivity of the as-prepared gas sensor has high selectivity to n-butanol and good response/recovery characteristics, linear response, short-term repeatability, as well as the long-term stability. The experimental results show that the gas sensor based on ZnO nanocrystalline can be used in the detection and real-time monitoring of toxic gases, especially n-butanol gas, which makes it to be highly promising candidate for practical detectors for n-butanol gas.

The raspberry-like SnO2 hollow nanostructure was synthesized by a simple hydrothermal method. The composition, microstructure, morphology, surface area and chemical states are investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N2 adsorption-desorption and X-ray photoelectron spectroscopy (XPS), respectively. The characterization results show that the raspberry-like SnO2 with a diameter of about 60 nm is composed of numerous SnO2 nanoparticles with grain size about 8 nm. The raspberry-like SnO2 was used as sensing material for gas sensor to detect n-butanol gas. The gas-sensing properties including gas response, selectivity, response-recovery time, repeatability, stability and dynamic response character were investigated carefully. It can be found that the response value of the sensor towards 100 ppm n-butanol gas was 303.49 at the low operating temperature of 160 °C. And the detection limit as low as 1 ppm. All results demonstrate the potential of using raspberry-like SnO2 for n-butanol gas detection. At the same time, the possible formation mechanism and gas-sensing mechanism were also discussed.

GAS is among the most common human pathogens and causes a wide variety of diseases, likely more than any other microorganism. The diverse clinical manifestations of GAS may be attributable to its large repertoire of virulence factors that are selectively and synergistically involved in streptococcal pathogenesis. To date, GAS vaccines have not been successful due to multiple serotypes and postinfection sequelae associated with autoimmunity. In this study, five conserved virulence factors that are involved in GAS pathogenesis were used as a combined vaccine. Intranasal immunization with this vaccine induced humoral and cellular immune responses across GAS serotypes and protected against mucosal, systemic, and skin infections. The significance of this work is to demonstrate that the efficacy of GAS vaccines can be achieved by including multiple nonredundant critical virulence factors and inducing local and systemic immunity. The strategy also provides valuable insights for vaccine development against other pathogens., Group A streptococcus (GAS) species are responsible for a broad spectrum of human diseases, ranging from superficial to invasive infections, and are associated with autoimmune disorders. There is no commercial vaccine against GAS. The clinical manifestations of GAS infection may be attributable to the large repertoire of virulence factors used selectively in different types of GAS disease. Here, we selected five molecules, highly conserved among GAS serotypes, and involved in different pathogenic mechanisms, as a multicomponent vaccine, 5CP. Intranasal (i.n.) immunization with 5CP protected mice against both mucosal and systemic GAS infection across serotypes; the protection lasted at least 6 months. Immunization of mice with 5CP constrained skin lesion development and accelerated lesion recovery. Flow cytometry and enzyme-linked immunosorbent assay analyses revealed that 5CP induced Th17 and antibody responses locally and systemically; however, the Th17 response induced by 5CP resolved more quickly than that to GAS when challenge bacteria were cleared, suggesting that 5CP is less likely to cause autoimmune responses. These findings support that immunization through the i.n. route targeting multiple nonredundant virulence factors can induce immunity against different types of GAS disease and represents an alternative strategy for GAS vaccine development, with favorable efficacy, coverage, duration, and safety.

High cycle fatigue and very high cycle fatigue properties of a surface-carburized CrNi steel were examined under axial loading with stress ratios of −1 and 0. The positive stress ratio overcomes the effect of carburized layer and promotes crack initiation from the carburized layer. The morphology of fine granular area (FGA) is more distinct under the negative stress ratio with more obvious crack closure effect. Two models concerning the inclusion-fisheye failure and the inclusion-FGA-fisheye failure are proposed. The predicted fatigue lives based on the concept of crack initiation are in good agreement with experimental results.

Cobalt ion (Co2+) is known to be harmful for human beings, and effectively portable sensor is one of the key for its prophylaxis and treatment. In this work, Zn(CH3COO)2·2H2O, Na2S·9H2O and thioglycolic acid were used to prepare ZnS quantum dots through a facile water-bath method. The structure and morphology of the ZnS quantum dots were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. Scanning electron microscope (SEM) was also used to observe the surface morphology of the test paper prepared by a simple dipping-drying process. The Co2+ sensing properties of as-prepared test paper were investigated. And it was found that the color of as-fabricated test paper could change from white to brown within 1 min with addition of Co2+ aqueous solution, which makes it possible for qualitative detection of Co2+ through naked eyes. In this mode, a widely detectable range from 10 to 1000 mg L−1 is reached by the test paper. In addition, through measuring the grey level of the test paper by ordinary smart phone and laptop, a semi-quantitative function of the test paper is realized. Moreover, the as-fabricated paper sensor can resist the interference of a serious cations and anions, and suits for a wide pH surrounding from 1.08 to 9.65, which makes it a promising Co2+ sensor for practical use. In addition, through X-ray diffraction and UV–vis spectra, the sensing properties of as-fabricated test paper are attributed to the chemical reaction between as-prepared ZnS quantum dots and Co2+ ions. And the formation of CoS2 should be responsible for the color change from white to brown.

This work uses ZnO nanoparticles as the probe and a case, proving that the grey level can replace fluorescent intensity to realize a quantitative detection function of paper-based Cu2+ sensor. Portable Cu2+ test papers were obtained through dipping filter papers in as-prepared ZnO sol possessing the Cu2+ quenching property. Based on grey level which is obtained through ordinary digital camera and computer, the detection function of the fabricated Cu2+ test paper is extended from qualitative detection relied on naked eyes to quantitative detection whose detection range is calculated to be 10–1000 μM. The fabricated test papers also could resist the interruption of some competing ions and is a potential candidate for portable Cu2+ detection device with quantitative function. Since the strategy of replacing fluorescence intensity by grey level is based on the map relationship between the fluorescence intensity and the digital signal (grey level), it is promising to be applied to other fluorescent test papers to gain quantitative test papers aimed at corresponding chemicals. At the same time, the mechanism of Cu2+-induced fluorescence quenching was also investigated by fluorescence lifetime, UV–vis spectra, and photoluminescence spectra. And a static quenching mechanism based on the non-fluorescence complex formed by Cu2+ and O x − is brought up.

The crack initiation and early growth behaviors of a TC4 titanium alloy under high cycle fatigue and very high cycle fatigue were experimentally investigated. The results show that it exhibits the duplex S–N curve characteristics associated with surface and interior failures at a stress ratio of 0.1, while it represents the similar S–N curve characteristics only related to surface failure at a stress ratio of −1. The interior failure is accompanied with the occurrence of facets, granular bright facets (GBFs), and fisheye. Slip-like patterns are observable on the facets easily formed under positive stress ratio. The interior failure process is characterized as (i) occurrence of slip lines on partial α grains under cyclic loading, (ii) initiation and growth of microcracks within some α grains, (iii) coalescence of microcracks and formation of GBF, (iv) stable long crack growth within fisheye, (v) unstable crack growth outside fisheye, and (vi) final momentary fracture.