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Insect olfactory systems can efficiently distinguish important host signals in a complex background of odor. Notably, Conopomorpha sinensis Bradley (Lepidoptera: Gracillariidae), a host-specific pest of Litchi chinensis and Euphoria longan, causes periodic outbreaks in southern China. However, little is known about the functions of host volatiles and olfactory mechanisms through which C. sinensis senses host taxa. Consequently, the present study analyzed the Electroantennogram (EAG) responses of C. sinensis antennae to host volatile compounds and their mixtures. The results showed that volatile components were more stimulatory to female than to male C. sinensis antennae. In addition, the highest EAG responses were observed following the stimulation of female antennae by the individual volatile component β-guaiene, followed by β-caryophyllene and β-elemene. However, odorant mixtures containing β-farnesene and α-pinene significantly altered EAG responses in female antennae. This was further confirmed by behavioral responses to host volatile compounds based on the flight orientation of females and males in a wind tunnel. These findings demonstrated that the behavior of C. sinensis can be affected by single compounds or a mixture of compounds. Moreover, real-time fluorescence quantitative PCR suggested that a combination of α-pinene with β-farnesene could alter the expression of olfactory genes. Therefore, screening for odors that can effectively alter the behavior of insects provides a theoretical basis for exploring host recognition and utilizing the olfactory networks of C. sinensis for biocontrol, at the molecular level.

In animals, early embryogenesis is maternally controlled, whereas in plants, parents contribute equally to the proembryo transcriptome. Thus, the question remains whether equivalent parental contribution to the transcriptome of the early proembryo means equal control of early embryogenesis. Here, on the basis of cell-lineage-specific and allele-specific transcriptome analysis, we reveal that paternal and maternal genomes contribute equally to the transcriptomes of both the apical cell lineage and the basal cell lineage of early proembryos. However, a strong maternal effect on basal cell lineage development was found, indicating that equal parental contribution to the transcriptome is not necessarily coupled with equivalent parental control of proembryonic development. Parental contributions to embryogenesis therefore cannot be concluded solely on the basis of the ratio of paternal/maternal transcripts. Furthermore, we demonstrate that parent-of-origin genes display developmental-stage-dependent and cell-lineage-dependent allelic expression patterns. These findings will facilitate the investigation of specific parental roles in specific processes of early embryogenesis.

The problem of dynamic stress concentration in anti-plane motion of a single circular cavity in a serrated boundary strip medium is studied. Firstly, the scattering of SH wave by a circular cavity ...

The practical application of the Li-S battery is restrained by the severe lithium polysulfide shuttle and sulfur insulation. In this work, the hollow V2O5 nanospheres wrapped by activated carbon as the host material for sulfur were prepared. The results indicate that initial specific discharge capacity of the electrode is 972 mA h g−1 and it can be maintained at 730 mA h g−1 after 200 cycles at 0.2 C. The average decay rate of the capacity for the AC@V2O5/S only is 0.09% per cycle after 200 cycles at 0.5 C. This excellent performance could result from the polar hollow V2O5 nanospheres providing more adsorption sites, which are conducive to electrolyte diffusion and confine polysulfides during the reaction of sulfur and polysulfide. Furthermore, the activated carbon coated on the outer layer can provide the large specific surface as conductive network. Therefore, this design strategy could show significant prospects for Li-S battery.

Conventional carbon materials have been widely used in electrochemical field, but the capacitance and energy density are not ideal. Herein, a plant bean sprout as carbon source and cerium nitrate as the catalyst precursor are intended to prepare electrode materials 3DPCS-x for high-performance supercapacitors. The 3DPCS-x is confirmed to be three-dimensional network and graphitic structure by FESEM and HR-TEM, and doped by heteroatom including N, O, and Ce elements. Among them, 3DPCS-700 exhibits excellent electrochemical performances with gravimetric capacitance reaches 421 F g−1 at 1 A g−1 and capacitance retention maintains 96.2% after 10,000 cycles. In addition, the capacitance of the 3DPCS-700 symmetric SC is 245 F g−1 at 1.5 A g−1 and the maximum energy density is 5.44 Wh Kg−1 at the power density of 300 W kg−1. Our work offers a powerful and sustainable pathway to link biological manner and energy storage beyond the scope of traditional synthetic chemistry.

BACKGROUND The limited amount of agrochemicals targeting plant bacterial diseases has motivated us to study innovative antibacterial surrogates with fresh modes of action. Notably, fabrication of violent apoptosis inducers to control the reproduction of pathogenic bacteria should be a feasible way to control plant bacterial diseases. To achieve this aim, we constructed a series of novel 18β-glycyrrhetinic piperazine amides based on the natural bioactive ingredient 18β-glycyrrhetinic acid to evaluate the in vitro and in vivo antibacterial activity and induced apoptosis behaviors on tested pathogens. RESULTS Screening results suggested that these designed compounds were extremely bioactive against two notorious pathogens, Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri. This conclusion was highlighted by the biological effects of compounds A3 and B1 , affording the related EC50 values of 2.28 and 0.93 μg mL-1 . In vivo trials confirmed the prospective application for managing rice bacterial blight disease with control efficiency within 50.57-53.70% at 200 μg mL-1 . In particular, target compounds could induce the generation of excessive reactive oxygen species (ROS) in tested pathogens, subsequently leading to a strong apoptotic effect at a very low drug concentration (≤ 10 μg mL-1 ). This finding was consistent with the observed ROS-enhanced fluorescent images and morphological changes of pathogens from scanning electron microscopy patterns. CONCLUSION Given these features, we anticipate that these novel piperazine-tailored 18β-glycyrrhetinic hybrids can provide an perceptible insight for fighting bacterial infections by activation of the apoptosis mechanism. Novel 18β-glycyrrhetinic piperazine amides were reported to have excellent antibacterial efficacy toward phytopathogens Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri. A possible apoptosis mechanism was proposed from the remarkable apoptotic behaviors triggered by target compounds. © 2020 Society of Chemical Industry.

The maturation of male and female gametophytes together with its impact on plant sexual reproduction has not received much attention, and the molecular mechanisms underlying the process are largely unknown. Here, we show that Arabidopsis DEAD-box RNA helicase 29 (RH29) is critical for the functional maturation of both male and female gametophytes. Homozygous rh29 mutants could not be obtained, and heterozygous mutant plants were semi-sterile. Progression of the cell cycle in rh29 female gametophytes was delayed. Delayed pollination experiments showed that rh29 female gametophytes underwent cell-fate specification but were unable to develop into functional gametophytes. Functional specification but not morphogenesis was also disrupted in rh29 male gametophytes, causing defective pollen tube growth in the pistil. RH29 was highly and specifically expressed in gametophytic cells. RH29 shares high amino acid sequence identity with yeast Dbp10p, which partially rescues the aborted-ovules phenotype of rh29/RH29 plants. RH29 is essential for the synthesis of REGULATORY PARTICLE TRIPLE A ATPase 5a (RPT5a), a subunit of the regulatory particle of the 26S proteasome. Our results suggest that gametophyte functional maturation is a necessary process for successful fertilization and that RH29 is essential for the functional maturation of both male and female gametophytes.

Monosaccharides play important roles in plant growth and development, and their biofunctions are closely related to their endogenous contents. Therefore, the determination of monosaccharides is beneficial for the further study of monosaccharide biofunction. In this work, we developed a liquid chromatography-mass spectrometry analytical method assisted by a post-column derivatization technique (LC-PCD-MS) for the fast and automatic determination of 16 monosaccharides in samples. Post-column chemical derivatization of monosaccharides was performed by a reaction of monosaccharides with 4-benzylaminobenzeneboronic acid (4-PAMBA) through boronate ester formation in a three-way connector. 4-PAMBA worked as a derivatization reagent to improve the selectivity and sensitivity of monosaccharide detection by MS. The developed LC-PCD-MS method integrates LC separation, chemical derivatization, and MS detection in one run, thus greatly reducing the analysis time for each sample. The limits of detection and limits of quantification for 16 monosaccharides were in the range of 0.002-0.1 and 0.007-0.5 ng/mL, respectively. Good linearity was obtained from the linear regression, with a determination coefficient (R2) ranging from 0.9928 to 1.0000. The relative recoveries were in the range of 80.7-117.8%, with the intra- and interday relative standard deviations less than 19.7 and 16.5%, respectively, indicating good accuracy and acceptable reproducibility of the method. Finally, the method was successfully applied to investigate the spatial and temporal distribution of 16 monosaccharides in the developing flower and germinating seed of Arabidopsis thaliana.

Various 1,4-benzoxazin-3-one derivatives containing propanolamine groups have been shown to exhibit good antibacterial activity against Pseudomonas syringae pv actinidiae (Psa), X. axonopodis pv citri (Xac) and Xanthomonas oryzae pv oryzae (Xoo). 1,4-benzoxazin-3-one 4n showed the best inhibitory effects against Psa, Xac and Xoo, exhibiting in vitro EC50 values of 4.95, 4.71 and 8.50 μg mL−1, respectively. These potencies were superior to the corresponding EC50 values of the commercial antibiotics bismerthiazol (BT, 89.10, and 116.90 μg mL−1) and thiodiazole copper (TC, 127.30, 82.73 and 87.50 μg mL−1). Treatment on the bacterial leaf blight of rice revealed that compound 4n displayed better curative (51%) and protective (48%) activities for reducing rice BLB than either BT (41%, 39%) or TC (43%, 41%). Scanning electron microscopy (SEM) imaging of Xoo that had been treated with 1,4-benzoxazin-3-one 4n (50–100 μg mL−1) revealed that the bacterial cells had experienced extensive cell wall damage, which is the likely cause of its antimicrobial activity and bacterial death.

Because only a handful of agrochemicals can manage bacterial infections, the discovery and development of innovative, inexpensive, and high-efficiency antibacterial agents targeting these infections are challenging. Herein, a series of novel epimeric and chiral 18β-glycyrrhetinic acid (GA) ester derivatives with various tertiary amine pendants were designed, synthesized, and screened for pharmacological activity. Results showed that some of the title compounds were conferred with significantly enhanced antibacterial activity toward phytopathogens

Since the frequency offset estimation (FOE) must be implemented before the subcarrier de-multiplexing and chromatic dispersion compensation (CDC) for digital subcarrier multiplexing (DSM) signals, traditional FOE algorithms for single carrier transmission is no longer suitable. Here, we propose a hardware-efficient blind FOE solution for the DSM signals by monitoring spectral dips in the frequency domain. With the use of a smoothing filter, the estimation accuracy of FOE can be significantly increased. Moreover, we identify that the proposed FOE method is robust to various transmission impairments, including amplified spontaneous emission (ASE) noise, optical filtering, and fiber nonlinearity. The effective function of the proposed FOE method is numerically and experimentally verified under scenarios of both back-to-back (B2B) and the 2560 km standard single-mode fiber (SSMF) transmission, leading to a FOE error less than 100 MHz with a FFT size of 1024.

With the merits of relatively high frequency response and large displacement, piezoelectric compliant mechanisms have been widely used in recent decades. In this paper, we share our recent investigation results on enhancing the dynamic bandwidth and flow rate of flexure-amplified piezoelectric flow control valves by employing compliant mechanisms. We have developed a rhombus-type compliant mechanism, which can actuate two small sliding spools by one group of piezo-stacks. Compared with the traditional nozzle flapper servo valve, it can effectively overcome internal leakage and oil contamination. The experimental results show that the step response time is 8.2ms and the bandwidth is about 100Hz.

Three hydrogen sulfide (H2S) probes based on an azonia–cyanine skeleton were successfully designed and prepared. Probe 1a, containing 4-chloro-7-nitro-1,2,3-benzoxadiazole connected to the cyanine dye, had an emission at 660 nm that was enhanced 4.5-fold by the reduced photoinduced electron transfer process when reacting with H2S. Probes 1b and 1c were constructed from cyanine dyes with electron withdrawing 2,4-dinitrophenyl and 7-nitrobenzo[c] [1,2,5]oxadiazol-4-yl groups, respectively. Probes 1b and 1c gave off−on type responses with 169- and 17-fold fluorescent enhancements at 639 nm with H2S. Their emission properties were influenced by intramolecular hydrogen bonds and intramolecular charge transfer processes. The detection limits of probes 1a–1c were calculated at 178, 121, and 9.6 nM, respectively. The intracellular imaging experiments with HeLa cells indicated probe 1a was a mitochondria-targeting H2S probe, while probes 1b and 1c were lysosome-targeting H2S probes.

Phytohormones play crucial roles in every aspect of plant life, and their regulatory functions rely on complex crosstalk networks among the different classes of phytohormones in an antagonistic or synergistic manner. Therefore, the simultaneous determination of multiclass phytohormones is important for studies of phytohormone functions and networks. However, due to the heterogeneity of the sensitivity resulting from structural diversity and the low content in the plant samples, simultaneous determination of multiclass phytohormones is challenging, especially in very tiny plant tissues or organs. Here, we describe a novel method for the simultaneous determination of 31 phytohormones from different classes in a single run. This uses a one-pot multifunctional derivatization coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). N, N-Diethyl ethylenediamine (DEED) and 2-methyl-4-phenylaminomethyl-benzeneboronic acid (2-methy-4-PAMBA) were used for derivatization of carboxylated phytohormones and brassinosteroids (BRs), respectively, to simultaneously improve detection sensitivities of carboxylated phytohormones and BRs. The method was fully validated for the 31 targeted phytohormones and could quantify multiclass endogenous phytohormones in small amounts of fresh plant samples (0.02-5 mg, FW). Finally, we used this method to investigate the spatial-temporal distribution of multiple phytohormones in reproductive organs of a single flower of Arabidopsis thaliana for the first time. This method could be a powerful auxiliary tool for studies of phytohormone functions and regulatory networks.

We present a silicon photonic dual parallel multielectrode Mach-Zehnder modulator (MEMZM) based transmitter targeting 200 Gb/s four-level pulse amplitude modulation (PAM4) short reach transceivers. The MEMZMs have an average V π and electro-optic (EO) bandwidth of 5 V and 38 GHz, respectively. The transmitter is characterized versus receiver equalizer taps, received signal power, driving voltage swing, crosstalk voltage swing, bitrate, and reach. Results reveal that using only a three-tap equalizer at the receiver, 100 Gb/s PAM4 net rate per lane can be achieved at a bit error rate (BER) below the KP4 forward error correction (KP4-FEC) threshold of 2.4 × 10 -4 . Moreover, up to 128 Gb/s can be received at a BER below the KP4-FEC threshold using only 2 Vpp and 1 Vpp driving the MEMZM segments. Then, both MEMZMs are driven simultaneously to assess the crosstalk impact on the BER performance at parallel operation. Driven by four binary signals, we demonstrate 200 Gb/s PAM4 transmission over up to 10 km of single mode fiber at a BER below the KP4-FEC threshold.

The addition of bisulfite to an electron-withdrawing double bond has been reported for the design of a bisulfite probe; however, the selectivity of this reaction is usually influenced by an oxidation reaction with hypochlorite. Herein, a probe (probe 1) with tetrahydroxanthylium and coumarin units was designed for the detection of bisulfite. The probe 1 exhibited high selectivity, an obvious colour change from blue to yellow and a large turn-on signal (144-fold enhancement) with green emission towards bisulfite in an acetonitrile-phosphate buffered saline (1 : 9, v/v) solution. In addition, an excellent linear relationship between the fluorescence intensity at 514 nm and bisulfite concentration (0–2 equivalent) was obtained. Moreover, the response time of the probe 1 towards bisulfite was within the order of several seconds, and the detection limit was calculated to be 22.8 nM. The mechanism of the detection reaction was proved by both the 1H NMR analysis and time-dependent density functional theory (TDDFT) calculations. The results of the fluorescence co-localization studies demonstrate that the probe 1 is a mitochondria-targeted fluorescent probe that can be used for the bioimaging of bisulfite in living HeLa cells.

Plant zygotes usually undergo asymmetrical cell division, giving rise to the formation of two daughter cells with distinct developmental cell fate. The small apical cell will develop into the major part of embryo proper, whereas the larger basal cell will divide to form a transient suspensor. Thus, the apical and basal cell lineages are an excellent model to study cell fate determination in relation to zygote polarity. However, the molecular mechanism underlying the differentiation of two distinct cell lineages is not yet understood, possibly due to the technique limitations. Previously, we have established a protocol for isolating apical cell and basal cell for cDNA library construction in tobacco. However, the method for isolating tiny Arabidopsis embryos has long been considered much more difficult. Here, we present a detailed protocol for isolating early Arabidopsis proembryos and separating apical and basal cell lineages of proembryos, which allow us to establish cell lineage-specific transcriptomes of early proembryos.

Lithium–sulfur battery hasreceived widespread attention because of its high energy density, low cost, environmental friendliness, and nontoxicity. However, the insulating properties of elemental sulfur, huge volume changes, and dissolution of polysulfides in electrolytes that result in the shuttle effect, low sulfur utilization, and low rate performance seriously hinder the commercialization of lithium–sulfur batteries. In this work, a composite material of nitrogen-doped multiwalled carbon nanotubes and V2O5 was designed and fabricated to serve as the positive electrode of lithium–sulfur battery via the hydrothermal method. The positive electrode of the V2O5@N-CNTs composite material could reach an initial discharge specific capacity of 1,453 mAh g−1at a rate of 0.1C. Moreover, the composite material could maintain a discharge ratio of 538 mAh g−1 at a rate of 0.5C even after 200 charge and discharge cycles. After 400 cycles, the composite had a specific discharge capacity of 439 mAh g−1 at a rate of 1.0C. The excellent electrochemical performance of the V2O5@N-CNT/S composite cathode material was due to the fact that V2O5 contains oxygen ions and has a strong polarized surface. Furthermore, nitrogen doping changed the hybrid structure of carbon atoms and provided additional active sites, thereby improving the conductivity of the material itself and effectively inhibiting the dissolution and diffusion of polysulfides.

The canonical acoustic dark energy model (cADE), which is based on a scalar field with a canonical kinetic term that rapidly converts potential to kinetic energy around matter radiation equality, alleviates the Hubble tension found in $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$. We show that it successfully passes new consistency tests in the cosmic microwave background (CMB) damping tail provided by the ACT data, while being increasingly constrained and distinguished from alternate mechanisms by the improved CMB acoustic polarization data from $Planck$. The best fit cADE model to a suite of cosmological observations, including the SH0ES ${H}_{0}$ measurement, has ${H}_{0}=70.25$ compared with $68.23\text{ }\text{ }(\mathrm{km}\text{ }{\mathrm{s}}^{\ensuremath{-}1}\text{ }{\mathrm{Mpc}}^{\ensuremath{-}1})$ in $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ and a finite cADE component is preferred at the $2.8\ensuremath{\sigma}$ level. The ability to raise ${H}_{0}$ is now mainly constrained by the improved $Planck$ acoustic polarization data, which also plays a crucial role in distinguishing cADE from the wider class of early dark energy models. Atacama Cosmology Telescope and $Planck$ TE polarization data are currently mildly discrepant in normalization and drive correspondingly different preferences in parameters. Improved constraints on intermediate scale polarization approaching the cosmic variance limit will be an incisive test of the acoustic dynamics of these models and their alternatives.

In order to solve the limitation of bus voltage deviation and uneven distribution of output current that traditional droop control is applied to DC microgrid, an improved droop control method is proposed. This method adopts the active measurement of line impedance and imports it into the sag coefficient by way of negative feedback, in order to Eliminate the adverse effects on the bus voltage and current distribution caused by the existence and inconsistency of the line impedance of each distributed power supply. Based on this theory, this paper calculates the line impedance by detecting the voltage difference between the head and the end of the line. Finally, the feasibility and effectiveness of the traditional droop control method are verified through modeling and simulation.

The seeds of land plants contain three genetically distinct structures: the embryo, endosperm, and seed coat. The embryo and endosperm need to interact and exchange signals to ensure coordinated growth. Accumulating evidence has confirmed that embryo growth is supported by the nourishing endosperm and regulated by signals originating from the endosperm. Available data also support that endosperm development requires communication with the embryo. Here, using single-fertilization mutants, Arabidopsis dmp8/9 and gex2, we demonstrate that in the absence of a zygote and embryo, endosperm initiation, syncytium formation, free nuclear cellularization, and endosperm degeneration are as normal as in the wild type in terms of the cytological process and time course. Although rapid embryo expansion accelerates endosperm breakdown, our findings strongly suggest that endosperm development is an autonomously organized process, independent of egg cell fertilization and embryo–endosperm communication. This work confirms both the altruistic and self-directed nature of the endosperm during coordinated embryo-endosperm development. The findings provide novel insights into the intricate interaction between the two fertilization products and will help to distinguish the real roles of the signaling between endosperm and embryo. These finding also shed new light on agro-biotechnology for crop improvement.

Vegetable oil is a major edible oil and an important industrial raw material. However, breeders have found it challenging to improve the oil content of crop seeds, and little is known about regulators with the potential to increase oil content via molecular engineering in modern oil crop breeding. We reported an F-box protein, Arabidopsis thaliana MYB Interaction Factor 1 (AtMIF1), which is a member of the ubiquitin-protein ligase E3 complex involved in the 26S proteasome protein degradation pathway. AtMIF1 physically interacts with MYB domain protein 5 (MYB5), which results in MYB5 degradation, so that transcriptional activation of the MYB/bHLH/WD-repeat (MBW) complex does not occur normally and GLABRA2 (GL2), encoding an inhibitor of oil content and functioning as a direct downstream gene of MBW, is not properly transcribed. AtMIF1 functioned as a positive regulator that increases oil content by attenuating GL2 inhibition. We overexpressed AtMIF1 and obtained transgenic plants with significantly higher seed oil contents. Importantly, both vegetative and reproductive growth of the transgenic plants appeared normal. In summary, this work reveals a novel regulator, AtMIF1, and a new regulatory pathway, 26S proteasome-AtMIF1-MYB5, for increasing the oil content of seeds without affecting plant growth, thus facilitating oil crop breeding.

Embryonic suspensor in angiosperms is a short-lived structure that connects the embryo to surrounding maternal tissues, which is necessary for early embryogenesis. Timely degeneration via programed cell death is the most distinct feature of the suspensor during embryogenesis. Therefore, the molecular mechanism regulating suspensor cell death is worth in-depth study for embryonic development. However, this process can hardly be detected using conventional methods since early embryos are deeply embedded in the seed coats and inaccessible through traditional tissue section. Hence, it is necessary to develop a reliable protocol for terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) analysis using limited living early embryos. Here, we provide a detailed protocol for the whole-mount detection of suspensor cell death using a TUNEL system in tobacco. This method is especially useful for the direct and rapid detection of the spatial-temporal characters of programed cell death during embryogenesis, as well as for the diminishment of the artifacts during material treatment by traditional methods.

In Arabidopsis, a zygote undergoes asymmetrical cell division that establishes the first two distinct cell types of early proembryos, apical and basal cells. However, the genome-wide transcriptional activities that guide divergence of apical and basal cell development remain unknown. Here, we present a comprehensive transcriptome analysis of apical and basal cell lineages, uncovering distinct molecular pathways during cell lineage specification. Selective deletion of inherited transcripts and specific de novo transcription contribute to the establishment of cell lineage-specific pathways for cell fate specification. Embryo-related pathways have been specifically activated in apical cell lineage since 1-cell embryo stage, but quick transcriptome remodeling toward suspensor-specific pathways are found in basal cell lineage. Furthermore, long noncoding RNAs and alternative splicing isoforms may be involved in cell lineage specification. This work also provides a valuable lineage-specific transcriptome resource to elucidate the molecular pathways for divergence of apical and basal cell lineages at genome-wide scale., Asymmetric division of the Arabidopsis zygote produces apical and basal cells that mainly develop into embryo and suspensor, respectively. Here, Zhou et al. show that de novo transcription and selective RNA turnover establish distinct apical and basal transcriptomes as early as the 1-cell stage of embryo development.

To investigate the relationship between functional groups on cellulose nanocrystals (CNC) and the performance of poly(β-hydroxybutyrate-co-valerate) (PHBV), the surface of CNC was modified by surface graft modification and PHBV/CNC biocomposites were prepared by melt blending. To demonstrate the interfacial adhesion difference between hydrophobic PHBV and hydrophilic CNC, palmitoyl chloride and e-caprolactone had been used to tailor the oleophilic property of CNC. Results showed that CNC had heterogeneous nucleation effect on the crystallization process of PHBV, while the entanglement of molecular chains weakened the promoting functions of CNC-g-C16 (CNC grafted with palmitoyl chloride) and CNC-g-CL (CNC grafted with e-caprolactone). Furthermore, CNC-g-CL exhibited better interfacial adhesion with PHBV when compared with CNC-g-C16. And 1 wt% CNC-g-CL improved the tensile strength of PHBV biocomposite to 38.09 MPa, which is 26.25% higher than PHBV.

The traditional theta modulator encodes input information by superimposing Ronchi sub-gratings, which is extremely easy to cause spatial channel overlap that results in bands mixing. In this case, we present an all-dielectric theta modulation meta-surface with a new encoding method, which separates red, green, blue, and achromatic spatial channels on the focal plane. The meta-surface ensures that the positions of focal points are relatively consistent while focusing energy into the sub-wavelength regions. Our study offers a way to facilitate device miniaturization and system integration, which may have an important application in compact multispectral photography only with one detector.

Zygotic embryogenesis is one of key processes for fertile seed development and therefore has gained great attention for decades in the field of plant developmental biology. However, this process is deeply embedded in the maternal tissues. The inaccessibility of tiny early embryos has greatly hindered the study of early embryogenesis, especially limits direct observation and accurate omics investigations. In order to investigate the molecular mechanism regulating embryo development with modern technologies, it is necessary to develop a reliable method to isolate living embryos at different stages. For this purpose, plant scientists have been trying to develop different methods for isolating zygotes and early embryos in different plants such as maize, wheat, rice, and tobacco during past decades. Nicotiana tabacum has long been considered as an ideal model eudicot for the study of embryogenesis, which displays a traceable and predictable cell division pattern, spanning from the first zygotic division to the mature embryo formation. Here, we provide a detailed protocol for isolating living embryos from zygote to cotyledon embryo. Isolated living zygotes and early embryos could be used for several important studies such as cell type-specific transcriptome construction and clear GFP observation.

Two probes based on tetrahydroxanthylium unit (probe 1a) and methyltetrahydroxanthylium unit (probe 1b) were designed and synthesized for the detection of hydrazine. Probes 1a–b exhibited turn-on red emission signal and high selectivity toward NH2NH2. The response time of probe 1a to NH2NH2 was more than 60 min, while that of probe 1b was less than 30 min. The detection limits of probes 1a–b were calculated as 210 nM and 110 nM respectively. What's more, the tolerance experiments showed that methyltetrahydroxanthylium unit possessed higher tolerance toward nucleophiles. Moreover, cells imaging experiments demonstrated that probe 1b could detect exogenous NH2NH2 in living HeLa cells.

Based on the industrialized reduced graphene oxide (RGO) product, the graphene precursor of RGO-TDI with reactive sites of isocyanate groups was prepared with high grafting ratio, and a series of PA6/RGO-TDI composites were prepared via reactive melt processing. The PA6 molecules were confirmed to reactively intercalate into RGO layers through covalent and hydrogen bonding, which had high grafting ratio and layer thickness, exhibiting almost monolayer dispersion state. The molecular bridge effect of exfoliated RGO-TDI lowered activation energy of electrically conductive network formation, which resulted in a rapid increase of electrical conductivity of the composites with a low threshold percolation.

Fully blind adaptive digital backpropagation (DBP) based on a steepest descent algorithm is proposed. For homogeneous links, a two-parameter blind adaptive (TBA) scheme is presented, which assumes that all DBP steps have the same nonlinear scaling factor and filter bandwidth parameter. For heterogeneous links, a multiparameter blind adaptive (MBA) scheme is proposed to achieve the optimal performance by adapting chromatic dispersion, nonlinear scaling factor, and bandwidth parameter of each DBP step. The principles and performance of the proposed schemes are presented for low-pass filter assisted DBP, denoted as LDBP, in single carrier systems and cross-phase modulation model based DBP in subcarrier-multiplexing (SCM) systems, denoted as SCM-DBP. In a 34.94 Gbaud dual-polarization 16QAM single channel transmission experiment with a homogeneous 2560 km link, we demonstrate that both TBA-LDBP and TBA-SCM-DBP can converge to optimal performance with various system configurations. In addition, for heterogeneous links, we show in simulations and experiments that MBA-LDBP and MBA-SCM-DBP achieve 0.2–1.4 dB improvement compared to their TBA counterparts.

Background Papain-like and legumain-like proteases are proteolytic enzymes which play key roles in plant development, senescence and defense. The activities of proteases in both families could be inhibited by a group of small proteins called cystatin. Cystatin family genes have been well characterized both in tobacco and rice, suggesting their potential roles in seed development. However, their potential targets, papain-like and legumain-like proteases, have not been well characterized in plants, especially in rice, a model plant for cereal biology. Results Here, 33 papain-like and 5 legumain-like proteases have been identified in rice genome, respectively. Gene structure, distribution in rice chromosome, and evolutionary relationship to their counterparts in other plants have been well characterized. Comprehensive expression profile analysis revealed that two family genes display divergent expression pattern, which are regulated temporally and spatially during the process of seed development and germination. Our experiments also revealed that the expression of most genes in these two families is sensitively responsive to plant hormones and different abiotic stresses. Conclusions Genome-wide identification and comprehensive gene expression pattern analysis of papain-like and legumain-like proteases in rice suggests their multiple and cooperative roles in seed development and response to environmental variations, which provides several useful cues for further in-depth study. Electronic supplementary material The online version of this article (10.1186/s12870-018-1298-1) contains supplementary material, which is available to authorized users.

We have developed and analysed logic NOR, NAND and XNOR gates based on two dimensional (2D) photonic crystals at a wavelength of 1.55 μm. The interference and self-collimation effects are used to design logic gates, which control the output by adjusting the phase difference to achieve constructive or destructive interference. The splitter is a line defect of the photonic crystal with a row of periodically arranged air rods. The radius of the defect rods depends on the function of the logic element. The use of these logic gates can reduce the size of logic devices.

We investigate the capacity improvement achieved by bandwidth variable transceivers (BVT) in meshed optical networks with cascaded ROADM filtering at fixed channel spacing, and then propose an artificial neural network (ANN)-aided provisioning scheme to select optimal symbol rate and modulation format for the BVTs in this scenario. Compared with a fixed symbol rate transceiver with standard QAMs, it is shown by both experiments and simulations that BVTs can increase the average capacity by more than 17%. The ANN-aided BVT provisioning method uses parameters monitored from a coherent receiver and then employs a trained ANN to transform these parameters into the desired configuration. It is verified by simulation that the BVT with the proposed provisioning method can approach the upper limit of the system capacity obtained by brute-force search under various degrees of flexibilities.

For the purpose of revealing the dynamic properties of elliptical inclusion in the half-space, solving the problem of scattered SH-wave, the method of ‘conformal mapping’ is used to map an elliptic...

During embryogenesis, plants are thought to use a mechanism that allows the suspensor to maintain its identity. Here, we reported that RPL18aB is involved in this mechanism in Arabidopsis thaliana. The suspensor cells proliferated in rpl18aB and formed a multicellular structure rather than undergo programmed cell death, as in wild type. Suspensors of rpl18aB expressed the embryo proper marker, DRN::GFP, but not the suspensor marker, WOX8::GFP. In addition, auxin accumulated throughout the suspensors of rpl18aB proembryos. Suspensor-specific expression of RPL18aB could rescue the cell proliferation defects in rpl18aB suspensors. These findings supported a role for RPL18aB in maintaining suspensor identity.

Conopomorpha sinensis Bradley is a host-specific pest of Litchi chinensis and Euphoria longan. Here, we demonstrated that C. sinensis has evolved special physical and chemical mechanisms for host plant location that enable it to survive and reproduce. Females favored laying their eggs on the convex surface of litchi fruit that had particular volatile characteristics. Experiments using a H-type olfactometer showed that female C. sinensis were attracted to litchi flowers, tender shoots, immature fruits, and mature fruits, with the highest attraction rate to mature fruits (74.67 ± 2.31%). There were no significant differences in the attraction of male C. sinensis to different litchi tissues. Further oviposition preference tests using the pericarp, pulp, and seeds of mature litchi fruits revealed that female C. sinensis prefer to lay their eggs on the pericarp. Litchi volatiles were found to be important in attracting C. sinensis to fruits for oviposition. Analysis of volatiles from different litchi tissues by HS-SPME-GC-MS revealed 31 similar volatiles, some of which may be important in the oviposition preference choices of C. sinensis on litchi fruit.

This paper proposes a kind of displaced thermal states (DTS) and explores how this kind of optical field emerges using the entangled state representation. The results show that the DTS can be generated by a coherent state passing through a diffusion channel with the diffusion coefficient ϰ only when there exists $\varkappa t = \left (e^{\hbar \nu /k_{B}T} - 1 \right )^{-1}$ . Also, its statistical properties, such as mean photon number, Wigner function and entropy, are investigated.

Signal molecule hydrogen peroxide (H2O2) plays critical roles in various processes of plant development. However, H2O2 signaling network, especially the responders that sense and respond to the H2O2 signal remain largely unknown. Here we report two homologous genes H2O2 Response Gene 1 and 2 (HRG1/2) in Arabidopsis that could quickly respond to exogenous or endogenous H2O2. Knockdown of HRG1/2 facilitated seed germination while overexpression of HRG1/2 greatly retarded seed germination. ROS level in HRG1 overexpression roots was significantly lower than that in HRG1/2 mutants after H2O2 treatment. The expression level of enzymatic antioxidant DHAR3 was upregulated in HRG1 overexpression plants, suggesting that DHAR3 is downstream of HRG1. That the root meristem length and cell number were significantly reduced in hrg1-1 and hrg2-1 plants upon H2O2 treatment compared to that of HRG1 overexpression plants also approves the idea that HRGs function in H2O2 removal. Further evolutionary analysis indicates that this is a dicotyledon-specific pathway responsive to H2O2. Together, this work reveals HRG1/2 as novel H2O2 responders involved in ROS scavenging to ensure embryonic root meristem activity. These findings provide valuable clues for the of H2O2 signaling and root meristem regulation.

Direct interaction between NtRPL17 and the kinesin NtKRP controls cell cycle progression in plants and reveals a novel regulatory role for ribosomal proteins in seed size establishment., We previously reported that a novel motor protein belonging to the kinesin-12 family, NtKRP, displays critical roles in regulating embryo and seed size establishment. However, it remains unknown exactly how NtKRP contributes to this developmental process. Here, we report that a 60S ribosomal protein NtRPL17 directly interacts with NtKRP. The phenotypes of NtRPL17 RNAi lines show notable embryo and seed size reduction. Structural observations of the NtRPL17-silenced embryos/seeds reveal that the embryo size reduction is due to a decrease in cell number. In these embryos, cell division cycle progression is delayed at the G2/M transition. These phenotypes are similar to that in NtKRP-silenced embryos/seeds, indicating that NtKRP and NtRPL17 function as partners in the same regulatory pathway during seed development and specifically regulate cell cycle progression to control embryo/seed size. This work reveals that NtRPL17, as a widely distributed ribosomal protein, plays a critical role in seed development and provides a new clue in the regulation of seed size. Confirmation of the interaction between NtKRP and NtRPL17 and their co-function in the control of the cell cycle also suggests that the mechanism might be conserved in both plants and animals.

Based on the industrialized reduced graphene oxide (RGO) product, MC nylon-6/RGO composites were in situ synthesized through anchoring effect of polyetheramine (PEA). Nylon-6 chains were confirmed to intercalate into RGO layers with high grafting ratio by formation of covalent bond and intermolecular hydrogen bond. By presence of PEA, RGO was well exfoliated by the nylon-6 chains and the average layer thickness increased remarkably. Moreover, the stacking of RGO layers was much more weakened and exhibited almost monolayer homogenous dispersion state in the matrix, resulting in the establishment of the electrically conductive network with a low threshold percolation.

The specific functions of the genes encoding arginine biosynthesis enzymes in plants are not well characterized. We report the isolation and characterization of Arabidopsis thaliana N-acetylglutamate kinase (NAGK), which catalyzes the second step of arginine biosynthesis. NAGK is a plastid-localized protein and is expressed during most developmental processes in Arabidopsis. Heterologous expression of the Arabidopsis NAGK gene in a NAGK-deficient Escherichia coli strain fully restores bacterial growth on arginine-deficient medium. nagk mutant pollen tubes grow more slowly than wild type pollen tubes and the phenotype is restored by either specifically through complementation by NAGK in pollen, or exogenous supplementation of arginine. nagk female gametophytes are defective in micropylar pollen tube guidance due to the fact that female gametophyte cell fate specification was specifically affected. Expression of NAGK in synergid cells rescues the defect of nagk female gametophytes. Loss-of-function of NAGK results in Arabidopsis embryos not developing beyond the four-celled embryo stage. The embryo-defective phenotype in nagk/NAGK plants cannot be rescued by watering nagk/NAGK plants with arginine or ornithine supplementation. In conclusion, our results reveal a novel role of NAGK and arginine in regulating gametophyte function and embryo development, and provide valuable insights into arginine transport during embryo development.

Metal contaminations from smelting have been widely reported, however, the study on metal mobility or transfer characteristics in soil profiles after a sudden wastewater overflow is far limited. This study was undertaken to investigate distribution and potential mobility of heavy metals in soils flooded by smelting wastewater in Hechi, China. Total heavy metal/metalloid levels were measured in topsoil, profile and profile pore-water taken in-situ. Enrichment factor (EF) and nemero synthesis index (P N ) were used to detect the contribution of anthropogenic emissions to trace element fluxes and pollution levels, respectively. Soil-water partition coefficient (K d ) was used to reflect the fate and the mobility of elements. Results showed topsoil were seriously contaminated with Sb (289–3100 mg kg − 1 ), Pb (444–6388 mg kg − 1 ), Zn (294–923 mg kg − 1 ), Cu (59–192 mg kg − 1 ), Cd (12–34 mg kg − 1 ), and As (32–405 kg − 1 ), and P N values indicated this area was in severe or strongly pollution level. Higher EF values of Sb, Zn, Cd and As were found in the flooded soils, and P N in flooded area was 5 times of that in the unflooded sites, indicating wastewater flooding aggregated pollution in the low-lying area. The Sb, Pb, and Cd concentrations declined drastically with profile but dropped to constant levels below a depth of about 20 cm. In contrast, Zn and Cu in flooding soils declined first and then increased to another extreme value even at depth of 50 cm. Pore-water profiles exhibited the similar declining trends of vertical metal/metalloid distribution pattern. The K d values ranged from 10 2 –10 6 L kg − 1 , and the mobility and bioavailability of the six elements in the profiles declined in the following order: Sb > Zn > Cu > Cd > As > Pb. The relatively low K d values for some depth intervals may reflect adsorption decrease or migration increase of metal/metalloid. However, it is worth to further study and assess their potential risk to environment in longer period.

Directly from the second order differential equations of satellite motion, the linearized orbital perturbation differential equations for CHAMP-like satellites are derived after introducing the reference orbit, and then introducing the omitted terms into the linearized orbital perturbation differential equations, the orbital perturbation differential equations with nonlinear corrections are derived. The accuracies for the orbital perturbation differential equations are estimated and the following results are obtained: if the measurement errors of the satellite positions and the non-gravitational accelerations are less than 3 cm and 3 × 10−10 m·s−2 respectively, the linearized orbital perturbation differential equations and the equations with nonlinear corrections can hold the accuracies 3 × 10−10 m·s−2 only when ρ ≤ 4.7 m and ρ ≤ 4.14 × 103 m respectively, where ρ is the distance between the satellite orbit and the reference one. Hence, compared with the linearized orbital perturbation differential equations, the equations with nonlinear corrections are suitable to establish normal system of equations of the gravity field's spherical harmonic coefficients in long time span. The solving method for the orbital perturbation differential equations is also given with the help of the superposition principle in the paper. At last, some imitation examples for CHAMP and GRACE missions are computed, and the results illustrate that the orbital perturbation differential equations with nonlinear corrections have higher accuracies than the linearized ones.

Graphene oxide (GO) was functionalized with polyetheramine (PEA) and MC nylon-6/reduced GO (rGO)-PEA composites were in situ synthesized. Intermolecular covalent and hydrogen bonding was confirmed to form for GO/PEA molecules, and the grafting ratio and average layer thickness exhibit a significant increase with PEA loading. Meanwhile the interlayer spacing (d 002 ) of GO-PEA increases steadily, and PEA chains adopt trans and planar zigzag conformation with arrangements of monolayer, bilayer in GO layers in the range of 100–400% PEA, while the completely exfoliated state of GO formed by saturation intercalation of 700% PEA. Compared with GO, the layer stacking of GO-PEA is much more weakened, exhibiting a wrinkled and almost monolayer dispersion state, which leads to a good dispersion of GO (rGO)-PEA in melting caprolactam and a much higher uniformity for the nylon-6 composites. The electrically conductive network formed, resulting in the remarkably improved electrical conductivity of the composites.

A series of monomer casting nylon-6 (MC PA6)/graphene (GN) nano-composites were in situ synthesized by incorporation of polyethylene glycol (PEG) as a solid lubricant and compatibilizer. Addition of PEG led to more efficient grafting of PA6 molecules on GN surface, while GN was exfoliated and uniformly distributed in the matrix. Compared with neat MC PA6, addition of only 0.5 wt% GN resulted in a roughly 12% increase in tensile strength and 20.6% increase in impact strength, while over 75% reduction in specific wear rate and 13% reduction in friction coefficient were obtained with 0.7 wt% GN addition. The worn surface displayed smooth and flat features with uniform depth distribution, and the annealing degree due to produced friction heat was much lower for the composites. The mechanical and tribological properties of the composites in presence of PEG were superior to those in absence of PEG, further confirming the synergistic reinforcing/lubrication effect of GN-PEG.

C17H21N4O5.5Zn, monoclinic, P21/c (no. 14), a = 9.4009(12) Å, b = 13.8160(18) Å, c = 15.1299(19) Å, β = 95.507(3)°, V = 1956.0(4) Å3, Z = 4, R gt(F) = 0.0590, wR ref(F 2) = 0.1495, T = 298(2) K.

Background The gradually elevated outbreak of plant bacterial diseases severely limits agricultural products and small amounts of pesticides can manage them. Our group has previously synthesized and screened the antimicrobial activity of diverse 1,3,4-oxadiazole thioether/sulfone compounds bridged by a sulfur atom at the 2-position of 1,3,4-oxadiazole. However, few studies have evaluated the effect of eliminating the sulfur atom on bioactivity. Herein, a novel type of N-containing heterocyclic pendants-tagged 1,3,4-oxadiazoles bridged by alkyl chains only was systematically synthesized and evaluated for their antimicrobial activities. Results Bioassay results revealed that antibacterial efficacy increased by 551- and 314-fold against the corresponding phytopathogens Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri compared to commercial agents bismerthiazol and thiodiazole copper. In vivo trials showed that C 1 exerted remarkable curative activity against rice bacterial blight with a control effectiveness of 52.9% at 200 μg mL-1 . Antibacterial mechanism research found that C 1 could reduce the hypersensitive response behavior and pathogenicity of Xoo through targeting the type III secretion system (T3SS) at a lower drug dose. This outcome was verified by observing the significantly down-regulated proteins and representative genes from the related quantitative proteomics and qRT-PCR assays. Conclusion This study can inspire the design of innovative molecular frameworks targeting the T3SS of phytopathogens for controlling bacterial infections. © 2020 Society of Chemical Industry.

In this work, polyamide 6 (PA6)/reduced graphene oxide (RGO)- toluene-2,4-diisocyanate (TDI) composites were fabricated by reactive melt processing, and effect of formation of crystalline/network structure on electrically conductive properties of the composites was studied. The molecular bridge effect of exfoliated RGO-TDI resulted in the homogeneous dispersion of RGO in PA6 matrix. Crystallization analysis shows that RGO facilitated the crystallization of PA6 matrix mainly via accelerating the generation of crystal nucleus, reaching maximum of Xc and minimum of crystal grain size upon RGO level of 1.66 vol.%, which confirmed the formation of most perfect crystalline structure. According to the dynamic rheological analysis, both frequency-independence of G’ and sharply reduce phase angle at low-frequency region with RGO loading level of 1.66 vol.% indicate the transition from liquid-like to solid-like rheological behavior, where terminal to non-terminal transition as well as Cole-Cole arc and rapidly increasing entanglement density confirm the formation of percolation network structure with RGO as a crosslinking center. Corresponding to the analysis above, the electrical conductivity of the nano-composites increased rapidly to the equilibrium value, resulting from the formation of perfect conductive network at RGO loading level of 1.66 vol.%, which was confirmed by TEM analysis.

The emergence and widespread occurrence of plant bacterial diseases that cause global production constraints have become major challenges to agriculture worldwide. To promote the discovery and development of new bactericides, imidazole-labeled 1,3,4-oxadiazole thioethers were first fabricated by integrating the crucially bioactive scaffolds of the imidazole motif and 1,3,4-oxadiazole skeleton in a single molecular architecture. Subsequently, a superior antibacterial compound A6 was gradually discovered possessing excellent competence against plant pathogens Xanthomonas oryzae pv oryzae and Xanthomonas axonopodis pv citri with EC50 values of 0.734 and 1.79 μg/mL, respectively. These values were better than those of commercial agents bismerthiazol (92.6 μg/mL) and thiodiazole copper (77.0 μg/mL). Further modifying the imidazole moiety into the imidazolium scaffold led to the discovery of an array of potent antibacterial compounds providing the corresponding minimum EC50 values of 0.295 and 0.607 μg/mL against the two strains. Moreover, a plausible action mechanism for attacking pathogens was proposed based on the concentration dependence of scanning electron microscopy, transmission electron microscopy, and fluorescence microscopy images. Given the simple molecular structures, easy synthetic procedure, and highly efficient bioactivity, imidazole (or imidazolium)-labeled 1,3,4-oxadiazole thioethers can be further explored and developed as promising indicators for the development of commercial drugs.

We present a novel CSPR controllable silicon photonic transmitter circuit based on a tunable power splitter for VSB self-coherent transmissions. 112 Gb/s 16 QAM over 80 km at a BER below 3.8×10−3 has been achieved.