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Flowering plants have evolved numerous intraspecific and interspecific prezygotic reproductive barriers to prevent production of unfavourable offspring1. Within a species, self-incompatibility (SI) is a widely utilized mechanism that rejects self-pollen2,3 to avoid inbreeding depression. Interspecific barriers restrain breeding between species and often follow the SI × self-compatible (SC) rule, that is, interspecific pollen is unilaterally incompatible (UI) on SI pistils but unilaterally compatible (UC) on SC pistils1,4–6. The molecular mechanisms underlying SI, UI, SC and UC and their interconnections in the Brassicaceae remain unclear. Here we demonstrate that the SI pollen determinant S-locus cysteine-rich protein/S-locus protein 11 (SCR/SP11)2,3 or a signal from UI pollen binds to the SI female determinant S-locus receptor kinase (SRK)2,3, recruits FERONIA (FER)7–9 and activates FER-mediated reactive oxygen species production in SI stigmas10,11 to reject incompatible pollen. For compatible responses, diverged pollen coat protein B-class12–14 from SC and UC pollen differentially trigger nitric oxide, nitrosate FER to suppress reactive oxygen species in SC stigmas to facilitate pollen growth in an intraspecies-preferential manner, maintaining species integrity. Our results show that SRK and FER integrate mechanisms underlying intraspecific and interspecific barriers and offer paths to achieve distant breeding in Brassicaceae crops.

Using unfamiliar and meaningless pictographs that varied in their degree of similarity to Chinese characters, the current study tested whether the early electrophysiological response was modulated by character likeness. We measured P100 and N170 while 20 native Chinese speakers were viewing Chinese characters, drawings of objects, and pictographs. Comparisons across the three categories of stimuli showed that pictographs elicited a smaller N170 amplitude than did Chinese characters and a stronger N170 amplitude than did objects, but did not differ in the P100 amplitude from the other two categories. Within the category of pictographs, stimuli with a higher degree of character likeness elicited larger N170 amplitudes and shorter N170 peak latencies, and this effect was again not observed in P100. These results suggest that N170 is sensitive to visual stimuli's character likeness even though they are unfamiliar pictographs with no meanings or sounds.

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In this present study, a fluorescent probe was developed to detect curcumin, which is derived from the rhizomes of the turmeric. We used a simple and economical way to synthesize boron and nitrogen co-doped carbon dots (BNCDs) by microwave heating. The maximum emission wavelength of the BNCDs was 450 nm at an excitation wavelength of 360 nm. The as-prepared BNCDs were characterized by multiple analytical techniques such as transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and infrared spectroscopy. Curcumin is a biologically active constituent of turmeric [1] which exhibits some biological and pharmacological activities such as antiinflammatory, [2] anti-ischemic, [3] antibacterial, [4] hepatoprotective, [5] anticarcinogenic, [6] and anti-dyspeptic [7] properties. It has also been reported that curcumin resists the formation of free radicals effectively such as superoxide radicals and hydroxyl radicals in blood and body tissues. [8,9] Due to the widespread application of curcumin in pharmacology and clinical medicine, much attention has been paid by researchers. Therefore, many methods for the detection of curcumin have been developed, including capillary electrophoresis, [10] high-performance thin-layer chromatographic, [11] high-performance liquid chromatography, [12,13] voltammetry, [14] liquid-liquid microextraction, [15] liquid chromatography-mass spectrometry, [16,17] and electrochemical techniques. [18] However, the majority of these Abbreviations used: BNCD, boron and nitrogen co-doped carbon dot; BSA, bovine serum albumin; CD, carbon dot; IFE, inner filter effect; PBS, phosphatebuffered solution; IR, infra-red; QY, quantum yield; TEM, transmission electron microscopy; UV, ultraviolet; XPS, X-ray photoelectron spectroscopy; XRD, X-ray diffraction.

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Based on commercial catalysts (V 2 O 5 −WO 3 /TiO 2 ), the effects of a selective catalytic reduction (SCR) system on the emission characteristics of fine particles were investigated. The size distribution, morphology, element compositions, and chemical compositions of fine particles at the outlet of the SCR system were measured by an electrical low pressure impactor (ELPI), particulate matter (PM 10 /PM 2.5 ) samplers, field emission scanning electron microscopy/energy dispersive spectrometry (FSEM−EDS), X-ray diffraction (XRD), etc. The influences of reaction conditions and flue gas components on fine particle formation were also studied. The results reveal that a large number of fine particles can be generated during the SCR process. These fine particles are mostly in the submicrometer size range and appear to be nonuniform. The main components of these fine particles are ammonium sulfate or ammonium bisulfate. There is a good correlation between the formation of fine particles and the SO 2 oxidation rate. Fine particle number concentration at the outlet of the SCR system increases obviously with the reaction temperature and molar ratio of NH 3 to NO (NSR, normalized stoichiometric ratio). Moreover, the enhancement of SO 2 , H 2 O, and O 2 concentrations in the inlet flue gas would increase the number concentration of the formed fine particles. The effects of the SCR process on the PM 2.5 emission characteristics consist of two aspects. On the one hand, some SO 2 can be oxidized to SO 3 during the SCR process at the function of the catalyst. Then SO 3 would react with NH 3 and H 2 O to form ammonium sulfate and ammonium bisulfate particles, which is a reversible process simultaneous with the deNOx reactions. On the other hand, SO 3 can also react with the escaped NH 3 and H 2 O to form ammonium sulfate and ammonium bisulfate particles after the SCR system.