Search

Ambient nitrate has been of increasing concern in PM2.5, while there are still large uncertainties in quantifying the formation of nitrate aerosol. The formation pathways of nitrate aerosol at an urban site and a suburban site in the Pearl River Delta (PRD) are investigated using an observation-constrained box model. Throughout the campaigns, aerosol pollution episodes were constantly accompanied with the increase in nitrate concentrations and fractions at both urban and suburban sites. The simulations demonstrate that chemical reactions in the daytime and at night both contributed significantly to formation of nitrate in the boundary layer at the two sites. However, nighttime reactions predominantly occurred aloft in the residual layer at the urban site, and downward transport from the residual layer in the morning is an important source (53 %) for surface nitrate at the urban site, whereas similar amounts of nitrate were produced in the nocturnal boundary layer and residual layer at the suburban site, which results in little downward transport of nitrate from the residual layer to the ground at the suburban site. We show that nitrate formation was in the volatile-organic-compound-limited (VOC-limited) regime at the urban site, and in the transition regime at the suburban site, identical to the response of ozone at both sites. The reduction of VOC emissions can be an efficient approach to mitigate nitrate in both urban and suburban areas through influencing hydroxyl radical (OH) and N2O5 production, which will also be beneficial for the synergistic control of regional ozone pollution. The results highlight that the relative importance of nitrate formation pathways and ozone can be site-specific, and the quantitative understanding of various pathways of nitrate formation will provide insights for developing nitrate and ozone mitigation strategies.

The transcription factor Ghd2 increases rice yield potential under normal conditions and accelerates leaf senescence under drought stress. However, its mechanism on the regulation of leaf senescence under drought stress remains unclear. In the present study, to unveil the mechanism, one target of Ghd2, the Rubisco activase gene RCA, was identified through the combined analysis of Ghd2-CRISPR transcriptome data and Ghd2-overexpression microarray data. Ghd2 binds to the 'CACA' motif in the RCA promoter by its CCT domain and upregulates RCA expression. RCA has alternative transcripts, RCAS and RCAL, which are predominantly expressed under normal conditions and drought stress, respectively. Similar to Ghd2-overexpressing plants, RCAL-overexpressing plants were more sensitive to drought stress than the wild-type. However, the plants overexpressing RCAS showed a weak drought-sensitive phenotype. Moreover, RCAL knockdown and knockout plants did not show yield loss under normal conditions, but exhibited enhanced drought tolerance and delayed leaf senescence. The chlorophyll content, the free amino acid content and the expression of senescence-related genes in the RCAL mutant were lower than those in the wild-type plants under drought stress. In summary, Ghd2 induces leaf senescence by upregulating RCAL expression under drought stress, and the RCAL mutant has important values in breeding drought-tolerant varieties.

Ghd7 is an important gene involving in photoperiod flowering pathway in rice. A Ghd7 involved transcriptional regulatory network has been established, but its translational regulatory pathway is poorly understood. The mutant suppressor of overexpression of Ghd7 (sog7) was identified from an EMS induced mutagenesis in the background ZH11 overexpressing Ghd7. MutMap analysis revealed that SOG7 is allelic to Ghd8 and delayed flowering under long-day (LD) conditions. Biochemical assays showed that Ghd8 interacts with OsHAP5C and Ghd7 both in vivo and in vitro. Surprisingly, a point mutation E96K in α2 helix of Ghd8 HFD domain destroyed its ability interacting with Ghd7. The prediction of the structure shows that mutated amino acid is located in the interaction region of CCT/NF-YB/YC complexes, which alter the structure of α4 of Ghd8. This structural difference prevents the formation of complex NF-YB/YC. The triple complex of Ghd8-OsHAP5C-Ghd7 directly bound to the promotor of Hd3a and downregulated the expression of Ehd1, Hd3a and RFT1, and finally resulted in a delayed heading. These findings are helpful to deeply understand the Ghd7 involved photoperiod flowering pathway and promote the elucidation of rice heading. This article is protected by copyright. All rights reserved.

Background Atrial fibrillation (AF) has the close relation to thyroid dysfunction and these two diseases lead to poor cardiovascular outcomes. But the prognostic value of thyroid diseases in AF remains unclear. We aimed to determine whether history of thyroid diseases is associated with risk of in-hospital cardiovascular outcomes in AF. Methods Based on the data from the CCC-AF (Improving Care for Cardiovascular Diseases in China-Atrial Fibrillation) project, 31,486 inpatients with a definitive diagnosis of AF and record of history of thyroid diseases were included. Logistic regression analysis was performed to investigate the relationship between history of thyroid diseases and risk of in-hospital major adverse cardiovascular events (MACE) in AF. Results Among AF patients, 503 (1.6%) had a history of hypothyroidism, 642 (2.0%) had a history of hyperthyroidism and 30,341 (96.4%) had no thyroid dysfunction. During this hospitalization, 5146 (16.3%) AF patients suffered from MACE. The incidence was 13.1% in hypothyroidism, 16.3% in euthyroidism and 19.0% in hyperthyroidism, in which there was a significant difference among three groups (p = 0.028). Multivariable logistic regression analysis revealed that history of hypothyroidism decreased but history of hyperthyroidism increased the risk of in-hospital MACE in AF patients (adjusted odds ratio [OR] = 0.603; 95% confidence interval [CI], 0.449–0.811; p = 0.001 versus adjusted OR = 1.327; 95% CI, 1.060–1.661; p = 0.013). Conclusion History of hypothyroidism was an independent protective factor, whereas history of hyperthyroidism was an independent risk factor for in-hospital cardiovascular outcomes in AF. Our study indicated that hyperthyroidism should be treated aggressively in order to improve the prognosis of AF.

This paper is concerned about the application of glow discharge plasma for the remediation of petroleum pollution of the sea. We used diesel fuel as the processing target and conducted a series of lab-scale studies. Several factors including the discharge voltage, gas flow rate, the concentration of NaCl, initial temperature, and initial concentration of diesel fuel can influence the performance of glow discharge plasma systems on removal efficiency of diesel fuel. To determine the optimal reaction conditions, the diesel degradation rate and energy efficiency were calculated. The experiment result for 2178 mg/L diesel fuel solution treatment was that removal efficiency of 93.3% was achieved after 12 min treatment with the energy yield of 17 g (kWh)−1. Higher voltage leads to larger removal efficiency, while the energy yield may be reduced. The removal efficiency of diesel fuel reached the maximum at the gas flow rate factor 700 mL/min, decreased with an increase in gas flow rate, and became a minimum value when the gas flow rate is 1000 mL/min as a result of the unstable discharge. Decreasing the concentration of sodium chloride can cause an increase in the removal efficiency of diesel fuel, because the conductivity tended to significantly increase the degradation efficiency. Moreover, temperature and initial concentration are demonstrated to have little influence on the rate constant, but higher initial concentration favors higher energy efficiency. During the remediation of diesel fuel, pH decreases to 2.76, while the conductivity of the solution and temperature are increased, especially for the temperature, which has an increase from 25 °C to 63 °C.

Littrow diffraction, the ability to reflect light back along incident direction, is a key functionality of retroreflectors, exhibiting wide applications in nanophotonics. However, retroreflectors have hitherto low working efficiencies and narrow bandwidths, and work only for a specific polarization, being unfavorable for integration-optics applications. Here, we propose a type of metagrating consisting of an all-dielectric Bragg reflector and a periodic metasurface with freeform-shaped dielectric resonators, which enables broadband depolarized perfect Littrow diffraction at optical frequencies. The physics is governed by exact cancellations of specular reflections contributed by two Bragg modes in metagratings, enabled by careful structural optimization to yield the desired reflection-phase difference of Bragg modes within a wide frequency band and for two polarizations. As a proof of concept, we experimentally demonstrate retroreflections with unpolarized absolute efficiency higher than 98% (99% in design) at 1030–1090 nm using multilayer freeform metagratings. Our results pave the way for numerous applications based on high-efficiency Littrow diffraction (e.g., spectral laser beam combining), which is not bonded to a specific polarization or frequency.

The phase transition from vegetative to reproductive growth is triggered by internal and external signals that participate in circadian clock in plants. We identified a rice floral inhibitor OsPRR73 encoding a CONSTANS protein. Overexpression of OsPRR73 resulted in late heading under both long-day (LD) and short-day (SD) conditions. Knockout mutants led to early heading under LD conditions but no change under SD. OsPRR73 mRNA accumulated at noon and exhibited a robust oscillation under constant light (LL) and constant darkness (DD) conditions. OsPRR73 overexpression exerted negative feedback on endogenous OsPRR73 expression and altered diurnal expressions of key flowering genes and circadian clock genes. OsPRR73 bound to the promoters of the floral gene Ehd1 and the circadian gene OsLHY, and significantly suppressed their expression at dawn. In LL and DD, the oscillatory patterns of the circadian genes OsLHY, OsTOC1, OsGI and OsELF3 were varied in OsPRR73OX and osprr73 mutants. OsPRR73 expression was decreased in osphyb mutants, and overexpression of OsPRR73 complemented the early heading date phenotype of osphyb, indicating OsPRR73 works downstream of OsPhyB. Therefore, OsPRR73 is involved in a feedback loop of the rice clock and connects the photoperiod flowering pathway by binding to the Ehd1 promoter in rice.

Background. Previous studies have shown that increased mean corpuscular volume (MCV) is an independent predictor for worse outcomes in coronary artery disease. However, as parameters to classify different types of anemia together with MCV, the relationship between mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and long-term outcomes in acute coronary syndrome (ACS) remains obscure. Moreover, few studies have compared the prognostic value of these red blood cell indices in anemic and nonanemic patients with ACS. Methods and Results. In this single-center observational cohort study, we enrolled 393 patients diagnosed with ACS, including 75 anemic and 318 nonanemic patients. The composite end points were defined as major adverse cardiovascular events (MACEs). After a median follow-up of 31.24 months, Kaplan–Meier survival analysis showed that higher MCV and MCH but not MCHC were significantly associated with increased MACEs in nonanemic ACS patients. Among the enrolled ACS patients without anemia, Cox regression analysis revealed that high MCV and MCH were correlated with increased MACEs after adjustment for cardiovascular risk factors, and receiver operating characteristic (ROC) curve analysis further confirmed the predictive value of high MCV and MCH. In bivariate correlation and linear regression analysis, plasma homocysteine was positively correlated with MCV and MCH but not MCHC in the nonanemic group even after adjusting for age, male sex, BMI, SBP, DBP, smoking, and diabetes. However, MCV, MCH, and MCHC showed no predictive value for MACEs, and no correlation was found between these red blood cell indices and homocysteine in ACS patients with anemia. Conclusion. After adjusting for cardiovascular risk factors, this study showed that higher admission MCV and MCH but not MCHC were independent predictors for long-term MACEs and positively correlated with homocysteine levels in the blood among the nonanemic but not anemic patients with ACS in China.

Higher alkanes are a major class of intermediate-volatility organic compounds (IVOCs), which have been proposed to be important precursors of secondary organic aerosols (SOA) in the atmosphere. Accurate estimation of SOA from higher alkanes and their oxidation processes in the atmosphere is limited, partially due to the difficulty of their measurement. High-time-resolution (10 s) measurements of higher alkanes were performed using NO+ chemical ionization in proton transfer reaction time-of-flight mass spectrometry (NO+ PTR-ToF-MS) at an urban site in Guangzhou in the Pearl River Delta (PRD) and at a rural site in the North China Plain (NCP). High concentrations were observed in both environments, with significant diurnal variations. At both sites, SOA production from higher alkanes is estimated from their photochemical losses and SOA yields. Higher alkanes account for significant fractions of SOA formation at the two sites, with average contributions of 7.0 % ± 8.0 % in Guangzhou and 9.4 % ± 9.1 % in NCP, which are comparable to or even higher than both single-ring aromatics and naphthalenes. The significant contributions of higher alkanes to SOA formation suggests that they should be explicitly included in current models for SOA formation. Our work also highlights the importance of NO+ PTR-ToF-MS in measuring higher alkanes and quantifying their contributions to SOA formation.

Background Prostate cancer (PCa) is a common malignant tumor of the genitourinary system. Clinical intervention in advanced PCa remains challenging. Tropomyosins 2 (TPM2) are actin-binding proteins and have been found as a biomarker candidate for certain cancers. However, no studies have explored the role of TPM2 in PCa and its regulatory mechanism. Methods TPM2 expression was assessed in Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) PCa patient dataset. The effect of TPM2 on PCa progression was assessed in vitro and in vivo by quantifying proliferation, migration, invasion and tumor growth assays, and the mechanism of TPM2 in PCa progression was gradually revealed by Western blotting, immunoprecipitation, and immunofluorescence staining arrays. Results TPM2 was found to be severely downregulated in tumor tissues of PCa patients compared with tumor-adjacent normal tissues. In vitro experiments revealed that TPM2 overexpression inhibited PCa cell proliferation, invasion and androgen-independent proliferation. Moreover, TPM2 overexpression inhibited the growth of subcutaneous xenograft tumors in vivo. Mechanistically, this effect was noted to be dependent on PDZ-binding motif of TPM2. TPM2 competed with YAP1 for binding to PDLIM7 through the PDZ-binding motif. The binding of TPM2 to PDLIM7 subsequently inhibited the nuclear transport function of PDLIM7 for YAP1. YAP1 sequestered in the cytoplasm phosphorylated at S127, resulting in its inactivation or degradation which in turn inhibited the expression of YAP1 downstream target genes. Conclusions This study investigated the role of TPM2, PDLIM7, and YAP1 in PCa progression and castration resistance. TPM2 attenuates progression of PCa by blocking PDLIM7-mediated nuclear translocation of YAP1. Accordingly, targeting the expression or functional modulation of TPM2, PDLIM7, or YAP1 has the potential to be an effective therapeutic approach to reduce PCa proliferation and prevent the progression of castration-resistant prostate cancer (CRPC).

The characterization of oxygenated organic compounds in urban areas remains a pivotal gap in our understanding of the evolution of organic carbon under polluted environments, as the atmospheric processes involving interactions between organics and inorganics, anthropogenic pollutants and natural emissions lead to formation of various and complex secondary products. Here, we describe measurements of an iodide chemical ionization time-of-flight mass spectrometer installed with a Filter Inlet for Gases and AEROsols (FIGAERO-I-CIMS) in both gas-phase and particle-phase at an urban site in Guangzhou, a typical mega-city in southern China, during the autumn of 2018. Abundant oxygenated organic compounds containing 2~5 oxygen atoms were observed, including organic acids, multi-functional organics typically emitted form biomass burning, oxidation products of biogenic hydrocarbons and aromatics. Photochemistry played dominant roles in the formation of gaseous organic acids and isoprene-derived organic nitrates, while nighttime chemistry contributed significantly to the formation monoterpene-derived organic nitrates and inorganics. Nitrogen-containing organic compounds occupied a significant fraction of the total signal in both gas and particle phases, with elevated fractions at higher molecular weights. Measurements of organic compounds in particle phase by FIGAERO-I-CIMS explained 24 % of the total organic aerosol mass measured by aerosol mass spectrometer (AMS), and the fraction increased for more aged organic aerosol. The systematically interpretation of mass spectra of the FIGAERO-I-CIMS in urban of Guangzhou provides a holistic view of numerous oxygenated organic compounds in the urban atmosphere, which can serve as a reference for the future field measurements by FIGAERO-I-CIMS in polluted urban regions.

The effects of interferon-γ (IFN-γ) on cholesterol accumulation and the development of foam cells are still unclear. In the present study, we found that IFN-γ promoted liver X receptor (LXR)-α degradation through the ubiquitin-proteasome system in macrophages. The process was dependent on its interactions with phosphorylated signal transducer and activator of transcription 1 (p-STAT1) and protein inhibitor of activated STAT 1 (PIAS1) because both fludarabine and PIAS1 shRNA reversed the decrease in LXR-α protein expression induced by IFN-γ. Additionally, IFN-γ enhanced the interactions of ubiquitin-conjugating enzyme 9 (UBC9), small ubiquitin-like modifier (SUMO)-1 and SUMO-2/3 with LXR-α. Moreover, treatment with shRNA specific for them not only reduced LXR-α polyubiquitination but also reversed the IFN-γ-induced decrease in its expression. Two specific sumoylation sites in LXR-α, K22 and K326, were indispensable for its IFN-γ-induced polyubiquitination because the K22R and K326R mutations inhibited the polyubiquitination and degradation of LXR-α in IFN-γ-treated macrophages. In addition, K22R or K326R mutation almost completely restored ATP-binding cassette subfamily G member 1 (ABCG1)-mediated cholesterol efflux in IFN-γ-treated macrophages. Taken together, these findings indicate that IFN-γ promotes LXR-α degradation through a SUMO-ubiquitin-dependent pathway, which may inhibit cholesterol efflux mediated by ABCG1 from macrophages and promote the development of atherosclerosis.

Volatile organic compounds (VOCs) play important roles in the tropospheric atmosphere. In this study, VOCs were measured at an urban site in Guangzhou, one of the mega-cities in Pearl River Delta (PRD) using a gas chromatograph mass spectrometer/flame ionization detection (GC-MS/FID) and a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS). Diurnal profile analyses show that stronger chemical removal by OH radicals for more reactive hydrocarbons during the daytime. Diurnal profiles of OVOCs indicate evidence of contributions from secondary formation. Detailed source analyses of OVOCs using a photochemical age-based parameterization method suggest important contributions from both primary emissions and secondary formation for measured OVOCs. During the campaign, around 1700 ions were detected in PTR-ToF-MS mass spectra, among of which 462 ions with noticeable concentrations. VOCs signals from these ions without calibration in PTR-TOF-MS are quantified based on sensitivities of available VOCs species. OVOC-related ions dominated PTR-ToF-MS mass spectra with an average contribution of 77.2 %. Combining measurements from PTR-ToF-MS and GC-MS/FID, OVOCs contribute 57.4 % to the total concentration of VOCs. Using concurrent measurement of OH reactivity, OVOCs measured by PTR-ToF-MS contribute greatly to the OH reactivity (19.3 %). In comparison, hydrocarbons account for 20.0 % of OH reactivity. Adding up the contributions from inorganic gases (47.9 %), ∼ 12 % of the OH reactivity remains as missing. Our results demonstrate the important roles of OVOCs in the emission and evolution budget of VOCs in urban atmosphere.

A dual-channel two-dimensional (2D) reflection grating filter operating around the 1.55 µm wavelength region is demonstrated, exhibiting dual-channel reflection peaks at 1.492 µm and 1.647 µm. The sidebands intrinsic to this kind of grating are suppressed by appropriately designed antireflective thin films, and this can be proved by equivalent medium theory. Using the modal analysis method, the excitation modes of the dual-channel reflection peaks are determined to be the TM0 (1.490 µm) and TE0 (1.638 µm) modes. The estimated relative errors in the wavelength determination of these modes are less than 1%. This is found to be in accord with analyses of the reflectivity spectra and electromagnetic fields. The dual-channel reflection peaks are sensitive to the background refractive index and may be useful in biosensing applications.

Higher alkanes are a major class of intermediate-volatility organic compounds (IVOCs), which have been proposed to be important precursors of secondary organic aerosols (SOA) in the atmosphere. Accurate estimation of SOA from higher alkanes and their oxidation processes in the atmosphere are limited, partially due to difficulty in their measurements. High-time resolution (10 s) measurements of higher alkanes were performed using a novel online mass spectrometry method at an urban site of Guangzhou in Pearl River Delta (PRD) and at a rural site in North China Plain (NCP), respectively. High concentrations were observed in both environments, with significant diurnal variations. At both sites, SOA production from higher alkanes is estimated from their photochemical losses and SOA yields. Higher alkanes account for significant fractions of SOA formation at the two sites, with average contributions of 7.0 ± 8.0 % in Guangzhou and 7.1 ± 9.5 % in NCP, which are comparable or even higher than both single-ring aromatics and naphthalenes. The significant contributions of higher alkanes in SOA formation suggests that they should be explicitly included in current models for SOA formation. Our work also highlights the importance of NO+PTR-ToF-MS in measuring higher alkanes and quantifying their contributions to SOA formation.

Isocyanic acid (HNCO) is a potentially toxic atmospheric pollutant, whose atmospheric concentrations are hypothesized to be linked to adverse health effects. An earlier model study estimated that concentrations of isocyanic acid in China are highest around the world. However, measurements of isocyanic acid in ambient air have not been available in China. Two field campaigns were conducted to measure isocyanic acid in ambient air using a high-resolution time-of-flight chemical ionization mass spectrometer (ToF-CIMS) in two different environments in China. The ranges of mixing ratios of isocyanic acid are from below the detection limit (18 pptv) to 2.8 ppbv (5 min average) with the average value of 0.46 ppbv at an urban site of Guangzhou in the Pearl River Delta (PRD) region in fall and from 0.02 to 2.2 ppbv with the average value of 0.37 ppbv at a rural site in the North China Plain (NCP) during wintertime, respectively. These concentrations are significantly higher than previous measurements in North America. The diurnal variations of isocyanic acid are very similar to secondary pollutants (e.g., ozone, formic acid, and nitric acid) in PRD, indicating that isocyanic acid is mainly produced by secondary formation. Both primary emissions and secondary formation account for isocyanic acid in the NCP. The lifetime of isocyanic acid in a lower atmosphere was estimated to be less than 1 day due to the high apparent loss rate caused by deposition at night in PRD. Based on the steady state analysis of isocyanic acid during the daytime, we show that amides are unlikely enough to explain the formation of isocyanic acid in Guangzhou, calling for additional precursors for isocyanic acid. Our measurements of isocyanic acid in two environments of China provide important constraints on the concentrations, sources, and sinks of this pollutant in the atmosphere.

In order to understand the stress of small through tied arch bridge. In this paper, the finite element simulation analysis of Lu Shanqu bridge is carried out in the completion stage by using MADIS / civil software, and the tie bars, arch ribs and suspenders of the superstructure are monitored. The results show that the axial force of the arch rib of this bridge is reduced by the balance of the tie rod, and the bending moment of the tie rod is greatly reduced by the action of the suspender. The stress characteristics of the bridge type are internal statically indeterminate and external statically indeterminate structure.

Ghd7, Ghd8, Ghd7.1, and Hd1 are all pleiotropic genes regulating heading date, plant height, and yield in rice. Early studies showed that Hd1 promoted heading under short-day conditions (SD) and delayed heading under long-day conditions (LD). Recent studies found that Hd1 also promoted heading in some genetic backgrounds under LD. In this study, we developed a series of near-isogenic lines for Ghd7, Ghd8, Ghd7.1, and Hd1 in the Zhenshan 97 (ZS97) and Minghui 63 (MH63) backgrounds and recorded their heading dates. In the ZS97 background, Ghd7 alone triggered the conversion of Hd1 function from promoting to suppressing heading under LD. Ghd8 alone and Ghd7.1 alone did not promote but enhanced Ghd7-mediated Hd1 function conversion. In the MH63 background, Ghd7 alone and Ghd7.1 alone did not convert Hd1 function under LD, but they jointly promoted Hd1 function conversion. Conversion of Hd1 function occurred only under LD but not SD. Transcript analysis showed that downregulation or upregulation of Ehd1 and Hd3a by Hd1 in the lines under LD was determined by genetic background. In summary, multiple gene combinations of Ghd7, Ghd7.1, and Ghd8 and unknown genes caused conversion of Hd1 function. Moreover, the different gene combinations had a big difference in photoperiod sensitivities. These findings lay a solid foundation for further unveiling the molecular mechanism of Hd1 function conversion and provide guidance for heading date improvement in rice.

Background Heading date is crucial for rice reproduction and geographic expansion. Many heading date genes are sensitive to photoperiod and jointly regulate flowering time in rice. However, it is not clear how these genes coordinate rice heading. Results Here, we performed a genetic interaction analysis among four major rice heading date genes Ghd7, Ghd8, OsPRR37/Ghd7.1 (hereafter PRR37) and Hd1 in the near-isogenic background under both natural long-day (NLD) and natural short-day (NSD) conditions. The 4-gene segregating population exhibited a large heading date variation with more than 95 days under NLD and 42 days under NSD conditions. Tetragenic, trigenic and digenic interactions among these four genes were observed under both conditions but more significant under NLD conditions. In the functional Hd1 backgrounds, the strongest digenic interaction was Ghd7 by Ghd8 under NLD but was Ghd7 by PRR37 under NSD conditions. Interestingly, PRR37 acted as a flowering suppressor under NLD conditions, while it functioned alternatively as an activator or a suppressor under NSD conditions depending on the status of the other three genes. Based on the performances of 16 homozygous four-gene combinations, a positive correlation between heading date and spikelets per panicle (SPP) was found under NSD conditions, but changed to a negative correlation when heading date was over 90 days under NLD conditions. Conclusions These results demonstrate the importance of genetic interactions in the rice flowering regulatory network and will help breeders to select favorable combinations to maximize rice yield potential for different ecological areas. Electronic supplementary material The online version of this article (10.1186/s12284-019-0314-x) contains supplementary material, which is available to authorized users.

The photonic spin Hall effect metasurfaces utilizing broadband highefficiency half-wave plate were proposed, which can generate broadband high- intensity left and right circular polarized light that could be applied in chiroptical spectroscopy.

The dual-channel two-dimensional reflection grating filter is demonstrated. The design of anti-reflective thin films suppresses the sidebands and the corresponding excitation modes of dual-channel reflection peaks are determined.

Figure S1. Development and genome composition of the rice populations. Figure S2. Genetic interaction analysis among Ghd7, Ghd8, PRR37 and Hd1 in the 4-gene segregating populations under NLD and NSD conditions. Figure S3. Genetic interaction analysis of Ghd7, Ghd8, PRR37 and Hd1 in the merged PRR37-segregating populations (NIL-F4) under NLD and NSD conditions. Figure S4. PRR37 delays the heading date in the ghd7ghd8Hd1 background under both LD and SD conditions. Table S1. Characteristics of four heading date genes and linked markers. Table S2. The monthly average day length of growing seasons at Wuhan and Lingshui. Table S3. Haplotypes of 10 heading date genes in ZS97. Table S4. The genetic interactions in the 4-gene segregating populations under NLD and NSD conditions. Table S5. The genetic interactions among four genes on the basis of the merged PRR37-segragating populations (NIL-F4) under NLD and NSD conditions. Table S6. The heading date and spikelets per panicle of 16 homozygous 4-gene combinations under NLD and NSD conditions. Table S7. Primers used in this study. (DOCX 1337 kb)

Several major heading date genes are sensitive to photoperiod and jointly regulate heading date in rice. However, it is not clear how these genes coordinate rice heading. In this study, a near-isogenic F2 population with Ghd7, Ghd7.1, Ghd8 and Hd1 segregating in the Zhenshan 97 (ZS97) background was used to evaluate the genetic interactions among these four genes under natural long-day (NLD) and natural short-day (NSD) conditions, and a series of Ghd7.1-segregating populations in different backgrounds were developed to estimate the genetic effects of Ghd7.1 on heading date under both conditions. Tetragenic, trigenic and digenic interactions among these four genes were observed under both conditions. In the functional Hd1 backgrounds, the strongest digenic interaction was Ghd7 by Ghd8 under NLD conditions but was Ghd7 by Ghd7.1 under NSD conditions. Interestingly, Ghd7.1 acted as a flowering suppressor under NLD conditions, while it functioned alternatively as an activator or a suppressor under NSD conditions depending on the status of the other three genes. Based on the performances of 16 homozygous four-gene combinations, a positive correlation between heading date and yield was found under NSD conditions, but changed to a negative correlation when heading date was over 90 days under NLD conditions. These results demonstrate the importance of genetic interactions in the rice flowering regulatory network and will help breeders to select favorable combinations to maximize rice yield potential for different ecological areas.

Broadband multilayer dielectric gratings (MDGs) with rectangular HfO2 grating profile were realized for the first time using a novel fabrication process that combines laser interference lithography, nanoimprint, atomic layer deposition and reactive ion-beam etching. The laser-induced damage initiating at the grating ridge was mitigated for two reasons. First, the rectangular grating profile exhibits the minimum electric-field intensity (EFI) enhancement inside the grating pillar compared to other trapezoidal profiles. Second, our etching process did not create nano-absorbing defects at the edge of the HfO2 grating where the peak EFI locates, which is unavoidable in traditional fabrication process. The fabricated MDGs showed a high laser induced damage threshold of 0.59J/cm2 for a Ti-sapphire laser with pulse width of 40 fs and an excellent broadband diffraction spectrum with 95% efficiency over 150 nm in TE polarization.

Motor vehicles contribute primarily and secondarily to air quality problems due to fine particle (PM2.5) and ozone (O3) pollution in China's megacities. Characterizing vehicle emission with the rapid change of vehicle numbers and fleet compositions is vital for both bottom-up emission survey and top–down source apportioning. To obtain emission factors (EFs) of PM2.5, carbonaceous aerosols and trace gases for road vehicles, in urban Guangzhou we conducted a field campaign in 2014 in the Zhujiang Tunnel, a heavily burdened tunnel with about 40,000 motor vehicles passing through each of its two separated bores per day. PM2.5 and volatile organic compounds (VOCs) were sampled for offline analysis while trace gases including SO2, NOx and CO were measured online and in situ. An eddy covariance system with an integrated 3-D sonic anemometer was also adopted to measure CO2 and winds inside the tunnel. We recorded an average fleet composition of 61% light-duty gasoline vehicles (LDVs) + 12% heavy-duty diesel vehicles (HDVs) + 27% liquefied petroleum gas vehicles (LPGVs), and EFs of 82.7 ± 28.3, 19.3 ± 4.7 and 13.3 ± 3.3 mg veh−1 km−1, respectively, for PM2.5, organic carbon (OC) and elemental carbon (EC). These EFs were respectively 23.4%, 18.3% and 72.3% lower when compared to that measured in the same tunnel in 2004. EFs of PM2.5, OC and EC were higher at night time (148 ± 126, 29 ± 24 and 21 ± 18 mg veh−1 km−1, respectively) due to significantly elevated fractions of HDVs in the traffic fleets. An average ratio of OC to EC 1.45 from this tunnel study was much higher than that of ∼0.5 in previous tunnel studies. The EFs of SO2, NOx, CO, CO2 and NMHCs for road traffic were also obtained from our tunnel tests, and they were 20.7 ± 2.9, (1.29 ± 0.2)E+03, (3.10 ± 0.68)E+03, (3.90 ± 0.49)E+05, and 448 ± 39 mg veh−1 km−1, respectively.

Through the introduction of a broadband ( ∼ 1 µ m ) high-efficiency (average above 90%) half-wave plate in the near-infrared (NIR) region, reflective Pancharatnam–Berry metasurfaces that can generate high-intensity (above 90%) left-circular polarization (LCP) and right-circular polarization (RCP) light for broadband ( ∼ 900 n m ) are designed. It provides a method to generate broadband high-efficiency circularly polarized (CP) light, which is a rare complex process in traditional chiroptical spectroscopy. To further show the broadband high-efficiency function of the meta-atom, a broadband high-efficiency reflective vortex beam generator based on metasurfaces is designed for RCP light in the NIR region. Moreover, with the appropriate arrangement, the metasurfaces are able to focus the vortex beam into a point to increase the intensity of the generated vortex beam.

Rice (Oryza sativa) is an important dietary source of both essential micronutrients and toxic trace elements for humans. The genetic basis underlying the variations in the mineral composition, the ionome, in rice remains largely unknown. Here, we describe a comprehensive study of the genetic architecture of the variation in the rice ionome performed using genome-wide association studies (GWAS) of the concentrations of 17 mineral elements in rice grain from a diverse panel of 529 accessions, each genotyped at ∼6.4 million single nucleotide polymorphism loci. We identified 72 loci associated with natural ionomic variations, 32 that are common across locations and 40 that are common within a single location. We identified candidate genes for 42 loci and provide evidence for the causal nature of three genes, the sodium transporter gene Os-HKT1;5 for sodium, Os-MOLYBDATE TRANSPORTER1;1 for molybdenum, and Grain number, plant height, and heading date7 for nitrogen. Comparison of GWAS data from rice versus Arabidopsis (Arabidopsis thaliana) also identified well-known as well as new candidates with potential for further characterization. Our study provides crucial insights into the genetic basis of ionomic variations in rice and serves as an important foundation for further studies on the genetic and molecular mechanisms controlling the rice ionome.

Optical metasurfaces, two-dimensional counterparts of the metamaterials, are comprised of arrays of subwavelength engineered inclusions that can locally modify optical field and light–matter interactions, thus offering fascinating possibilities to realize unprecedented photonic phenomena. Here, a micro-structured optical coating or a hybrid multilayer structure is proposed. It is easy to achieve phase control over 2π by changing the geometric parameter, which is used to design gradient metasurface exhibiting anomalous reflection for linearly polarized light (1μm). By arranging the arrays elaborately, the efficiency can reach as high as 93.6%. Besides, reflective metalens taking advantage of the Pancharatnam-Berry phase is demonstrated. The electric field distribution unambiguously indicates that the metalens can focus the plane wave with high efficiency (60.3%). Such structure may find various potential applications in nanophotonics because of their high freedom to design metasurfaces.

Rice cultivars have been adapted to favorable ecological regions and cropping seasons. Although several heading date genes have separately made contributions to this adaptation, the roles of gene combinations are still unclear. We employed a map-based cloning approach to isolate a heading date gene, which coordinated the interaction between Ghd7 and Ghd8 to greatly delay rice heading. We resequenced these three genes in a germplasm collection to analyze natural variation. Map-based cloning demonstrated that the gene largely affecting the interaction between Ghd7 and Ghd8 was Hd1. Natural variation analysis showed that a combination of loss-of-function alleles of Ghd7, Ghd8 and Hd1 contributes to the expansion of rice cultivars to higher latitudes; by contrast, a combination of pre-existing strong alleles of Ghd7, Ghd8 and functional Hd1 (referred as SSF) is exclusively found where ancestral Asian cultivars originated. Other combinations have comparatively larger favorable ecological scopes and acceptable grain yield. Our results indicate that the combinations of Ghd7, Ghd8 and Hd1 largely define the ecogeographical adaptation and yield potential in rice cultivars. Breeding varieties with the SSF combination are recommended for tropical regions to fully utilize available energy and light resources and thus produce greater yields.

Previous studies suggested that Hd1 promoted heading under short-day conditions (SD) and delayed heading under long-day conditions (LD). However in this study, Hd1 was demonstrated to consistently promote heading date in Zhenshan 97 (ZS97) background by upregulating Ehd1, Hd3a and RFT1 expression under both SD and LD. While the high photoperiod sensitivity of Hd1 was observed in Minghui 63 (MH63) background, with heading being suppressed in LD but promoted in SD. Comparative analysis of two sets of near isogenic lines of Hd1 in MH63 and ZS97 backgrounds indicated that the alternative functions of Hd1 in promoting or suppressing heading under LD are dependent on the previously cloned flowering repressor gene Ghd7. The interaction between proteins Ghd7 and Hd1 occurred through binding of the CCT domain of Ghd7 to the transcription-activating domain of Hd1, resulting in suppression of Ehd1 and florigen gene expression. The involvement of the transcription-activating domain of Hd1 in this protein-protein interaction probably blocked or weakened its transcriptional activity. These findings suggest that Hd1 alone essentially acts as a promoter of heading date, and the protein interaction between Ghd7 and Hd1 determines photoperiod sensitivity and integrated Hd1-mediated and Ehd1-mediated flowering pathways in rice.

An automatic gas chromatograph system equipped with a mass spectrometer and a flame ionization detector (GC-MS/FID) was developed for online measurements of volatile organic compounds (VOCs) in the atmosphere. This system consisted of a custom-built cryogen-free cooling device that can create an ultra-low temperature of −165 °C, a two-channel sampling and pre-concentration system, and a commercial GC-MS/FID. One channel in the sampling and pre-concentration system was designated to trap C2–C5 hydrocarbons, whereas the other was designed to trap other VOC species. The newly developed GC-MS/FID system was then employed to measure VOCs in ambient air, and its observation data were compared with those from three well-established techniques, including an offline GC-MS/FID coupled with canister sampling, a proton transfer reaction-mass spectrometer (PTR-MS), and an online gas chromatograph system equipped with an FID and a photo ionization detector (GC-FID/PID). The online and offline GC-MS/FID measurements for alkanes, acetylene, C2–C3 alkenes, C6–C8 aromatics, and halocarbons showed good agreement. In addition, the online GC-MS/FID measurements for C6–C9 aromatics, acetone, and methacrolein + methylvinylketone (MACR + MVK) agreed well with the PTR-MS observations. Mixing ratios of C2–C7 alkanes, C3–C5 alkenes, and C6–C8 aromatics also showed good agreement between the online GC-MS/FID and GC-FID/PID techniques. These inter-comparison results demonstrated the accuracy of online GC-MS/FID measurements for C2–C12 NMHCs, C3–C4 carbonyls, and halocarbons.