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Enzyme-free catalytic amplification is of great significance for sensitive label-free electrochemical immunosensors. In this study, an enzyme-free catalytic amplification based label-free amperometric immunosensor was developed for sensitive detection of neuron-specific enolase (NSE) by use of a AuPd nanoparticle-multiwalled carbon nanotube (AuPd-MWCNT) composite, ferrocenecarboxaldehyde (Fc-CHO), and chitosan hybrid hydrogel. The intrinsic virtues of chitosan not only resulted in bioactivity of the attached antibodies and made the other component of the immunosensor easier to fix on the electrode, but also imparted abundant binding sites to the hydrogel to condense Fc-CHO to achieve the initial signal amplification. Fc-CHO, which served as an electroactive species to generate a redox response, also exhibits excellent electrocatalytic activity toward HO. AuPd-MWCNT composite, with enhanced peroxidase-like catalytic activity, could catalyze HO to accelerate electron transfer. When HO was present in the detection solution, synergetic catalysis of Fc-CHO and AuPd-MWCNT composite toward HO was achieved, thus realizing enzyme-free signal amplification. On the basis of this enzyme-free signal amplification, the electrochemical immunosensing platform provided a wide linear range from 1 pg mL to 100 ng mL, a low detection limit of 0.483 pg mL, and high sensitivity of 7.22 μA (log C ). Moreover, the immunosensor showed enormous potential in clinical application. [ABSTRACT FROM AUTHOR]

Enzyme-free catalytic amplification is of great significance for sensitive label-free electrochemical immunosensors. In this study, an enzyme-free catalytic amplification based label-free amperometric immunosensor was developed for sensitive detection of neuron-specific enolase (NSE) by use of a AuPd nanoparticle-multiwalled carbon nanotube (AuPd-MWCNT) composite, ferrocenecarboxaldehyde (Fc-CHO), and chitosan hybrid hydrogel. The intrinsic virtues of chitosan not only resulted in bioactivity of the attached antibodies and made the other component of the immunosensor easier to fix on the electrode, but also imparted abundant binding sites to the hydrogel to condense Fc-CHO to achieve the initial signal amplification. Fc-CHO, which served as an electroactive species to generate a redox response, also exhibits excellent electrocatalytic activity toward HO. AuPd-MWCNT composite, with enhanced peroxidase-like catalytic activity, could catalyze HO to accelerate electron transfer. When HO was present in the detection solution, synergetic catalysis of Fc-CHO and AuPd-MWCNT composite toward HO was achieved, thus realizing enzyme-free signal amplification. On the basis of this enzyme-free signal amplification, the electrochemical immunosensing platform provided a wide linear range from 1 pg mL to 100 ng mL, a low detection limit of 0.483 pg mL, and high sensitivity of 7.22 μA (log C ). Moreover, the immunosensor showed enormous potential in clinical application. [ABSTRACT FROM AUTHOR]

The phase equilibria of the Bi-Cu-Zn ternary system has been firstly and comprehensively investigated by electron probe microanalyzer (EPMA) with equilibrated alloys. Two isothermal sections of the Bi-Cu-Zn ternary system at 500 and 650 °C were determined. Based on the experimental data of phase equilibria, the Bi-Cu-Zn ternary system was also thermodynamically optimized using the Calculation of Phase Diagrams (CALPHAD) method. The experimental result shows that Bi is almost insoluble in the Cu-Zn binary compounds and (Cu) phase. It is found that the critical temperatures of the miscibility gaps in the Bi-Cu and Bi-Zn binary systems gradually increase with the increasing of the third element Zn or Cu additions. Moreover, the composition range of the liquid miscibility gap gradually reduces with the temperature increasing. [ABSTRACT FROM AUTHOR]

Tomato spotted wilt virus (TSWV) causes major losses of many crops worldwide. Several strategies have been attempted to control disease caused by TSWV. However, many challenges for the effective control of this disease remain. A promising approach is the use of abiotic or biotic inducers to enhance plant resistance to pathogens. We screened a diterpenoid compound from Wedelia trilobata, 3α-Angeloyloxy-9β-hydroxy-ent-kaur-16-en-19-oic acid (AHK), which had higher curative and protective effects against TSWV than the ningnanmycin control. The rapid initiation of the expression of all the TSWV genes was delayed by more than 1d in the curative assay, and the expression of the NSs, NSm and RdRp genes was inhibited. In addition, the replication of all TSWV genes in systemic leaves was inhibited in the protective assay, with an inhibition rate of more than 90%. The concentrations of jasmonic acid (JA) and jasmonic acid isoleucine (JA-ILE) in the AHK-treated and systemic leaves of the treated plants were significantly higher than those observed in the control. The results suggested that AHK can induce systemic resistance in treated plants. The transcription of the NtCOI1 gene, a key gene in the JA pathway, was significantly higher in both the inoculated and systemic leaves of the AHK-treated plants compared to the control. The AHK-induced resistance to TSWV in Nicotiana benthamiana could be eliminated by VIGS-mediated silencing of the NtCOI1 gene. These results indicated that AHK can activate the JA pathway and induce systemic resistance to TSWV infection. [ABSTRACT FROM AUTHOR]

A bidirectional labeling method was established to distinguish the proportions of HCO3− and CO2 utilization pathways of microalgae in Lake Hongfeng. The method was based on microalgae cultured in a medium by adding equal concentrations of NaH13CO3 with different δ13C values simultaneously. The inorganic carbon sources were quantified according to the stable carbon isotope composition in the treated microalgae. The effects of extracellular carbonic anhydrase (CAex) on the HCO3− and CO2 utilization pathways were distinguished using acetazolamide, a potent membrane-impermeable carbonic anhydrase inhibitor. The results show utilization of the added HCO3− was only 8% of the total carbon sources in karst lake. The proportion of the HCO3− utilization pathway was 52% of total inorganic carbon assimilation. Therefore, in the natural water of the karst area, the microalgae used less bicarbonate that preexisted in the aqueous medium than CO2 derived from the atmosphere. CAex increased the utilization of inorganic carbon from the atmosphere. The microalgae with CAex had greater carbon sequestration capacity in this karst area. [ABSTRACT FROM AUTHOR]

In this study, we aimed to determine whether liraglutide could effectively reduce insulin resistance (IR) by regulating Sestrin2 (SESN2) expression in L6 rat skeletal muscle cells by examining its interactions with SESN2, autophagy, and IR. L6 cells were incubated with liraglutide (10–1000 nM) in the presence of palmitate (PA; 0.6 mM), and cell viability was detected using the cell counting kit-8 (CCK-8) assay. IR-related and autophagy-related proteins were detected using western blotting, and IR and autophagy-related genes were analyzed using quantitative real-time polymerase chain reaction. Silencing SESN2 was used to inhibit the activities of SESN2. A reduction in insulin-stimulated glucose uptake was observed in PA-treated L6 cells, confirming IR. Meanwhile, PA decreased the levels of GLUT4 and phosphorylation of Akt and affected SESN2 expression. Further investigation revealed that autophagic activity decreased following PA treatment, but that liraglutide reversed this PA-induced reduction in autophagic activity. Additionally, silencing SESN2 inhibited the ability of liraglutide to up-regulate the expression of IR-related proteins and activate autophagy signals. In summary, the data showed that liraglutide improved PA-induced IR in L6 myotubes by increasing autophagy mediated by SESN2. [ABSTRACT FROM AUTHOR]

In this paper, it is proposed to combine multiple plasmon resonances and Fabry–Perot-like resonance to realize broadband transmission polarization conversion metasurface (TPCM). The broadband TPCM was designed using cross-shaped resonators and two metal gratings. It is shown that the multiple plasmon resonances can greatly expand the polarization conversion bandwidth, and the Fabry–Perot-like resonance can greatly improve its efficiency, the efficient broadband TPCM is realized through their combination. The broadband TPCM of different frequency bands can be obtained by changing the structure parameters. A set of parameters were selected for simulation and experiment to verify the design. The simulation results show that the TPCM can convert linearly polarized waves into its cross-polarized waves with 2 dB bandwidth of 8.1–26.8 GHz and the PCR is greater than 98%. As the oblique incident angle is up to 45°, the cross-polarization transmission is still greater than − 2 dB in the frequency range of 17.0–26.4 GHz, greater than − 3 dB in the frequency range of 8.0–15.8 GHz, and the PCR is more than 97%. The experimental results are in good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

In this paper, a broadband polarization conversion metasurface in microwave regime based on cross-shaped resonators was proposed. The simulated results show that the converter can convert linear polarization wave into its cross-polarization wave, 2 dB bandwidth is 11.5–21.8 GHz, and the Polarization Conversion Ratio is greater than 96% in this range. The simulated surface current distributions show that there are three plasmon resonances generated by magnetic resonances and electric resonance, resulting in broadband cross-polarized reflections, and electromagnetic composite resonances in the same direction will inhibit cross-polarization reflection. The proposed converter presents polarization selectivity, which can only convert the y- and x-polarized waves completely. When the incident angles reach 40°, the converter also shows high-efficiency polarization conversion. The experimental results are highly consistent with the simulation ones. This work may have some potential application in polarization-controlled devices, stealth surfaces, antennas and etc. [ABSTRACT FROM AUTHOR]

Representation and parameterization of freeform feature is one key issue in CAD. Based on the idea of layering freeform feature and feature global shape (FGS), a novel method for classification and parametric representation of freeform feature is proposed. Firstly, freeform features are classified in use of a multi-side method which combines FGS, approaches for surface generation, types of characteristic curves and their topological structures. Secondly, freeform feature is parameterized step by step from global to local shape, from basic to fine characteristic, and from high to low level, thus its representation can be unified. Lastly, the framework of three-level structures and two-grade mappings is put forward to define freeform feature so that parametric semantics can be clearer and it is convenient for users to edit and modify surface by intuitive parameters. It is shown in the examples that the method can effectively improve classification and parameterization of freeform feature. It can be applied to surface feature-based design and other domains as well. [ABSTRACT FROM AUTHOR]

Female germline cells in flowering plants differentiate from somatic cells to produce specialized reproductive organs, called ovules, embedded deep inside the flowers. We investigated the molecular basis of this distinctive developmental program by performing single-cell RNA sequencing (scRNA-seq) of 16,872 single cells of Arabidopsis thaliana ovule primordia at three developmental time points during female germline differentiation. This allowed us to identify the characteristic expression patterns of the main cell types, including the female germline and its surrounding nucellus. We then reconstructed the continuous trajectory of female germline differentiation and observed dynamic waves of gene expression along the developmental trajectory. A focused analysis revealed transcriptional cascades and identified key transcriptional factors that showed distinct expression patterns along the germline differentiation trajectory. Our study provides a valuable reference dataset of the transcriptional process during female germline differentiation at single-cell resolution, shedding light on the mechanisms underlying germline cell fate determination. Zhimin Hou, Yanhui Liu et al. used single cell RNA-seq to analyze the model organism, Arabidopsis thaliana, at three stages during female germline differentiation. They reconstructed the continuous trajectory of female germline differentiation, providing a valuable reference for future investigation of germline cell fate determination in A. thaliana. [ABSTRACT FROM AUTHOR]

Trees are considered to be an effective tool for improving human thermal comfort in hot climates and have been widely used in landscape architecture. However, it is not always clear how trees affect human-environment energy fluxes. In this study, an in-depth analysis of four common tree species was undertaken based on comprehensive field measurements, in terms of how each tree and its characteristics affected the energy fluxes of a person in a humid subtropical climate region. Results showed that the largest effect of trees was on radiation fluxes, with a much smaller effect on the convective and evaporative fluxes. For a person standing in shade, a tree can reduce approximately 25% of the absorbed radiation compared with an open reference point. Moreover, the cooling effect on radiation components was found to be greater in the solar radiation domain than in the terrestrial radiation domain. Solar radiation and ground surface temperature had the largest effect on a human energy budget, which was affected by characteristics of the trees and the thermophysical properties of ground surfaces. The effect from relative humidity and wind speed was quite minimal. For the four common tree species in this study, Ficus microcarpa had the best thermal performance by reducing the most absorbed solar radiation flux. This study shows a detailed empirical research about the thermal effects of trees on a person, providing recommendations for tree species selection in urban design. [ABSTRACT FROM AUTHOR]

Quantum cascade laser (QCL) emitting at 4.8 $$\upmu $$ m with a single-longitudinal mode and small divergence was achieved by integrating porous (PS) waveguide structure and distributed feedback (DFB) grating. The PS waveguide is fabricated in highly doped InP cladding layer by electro-chemical etching process. The DFB grating was defined above the active region by holographic lithography technique. A fundamental transverse mode of single-lobed radiation far-field pattern with full width at half maximum of 7.8 $$^{\circ }$$ was obtained. Single-longitudinal mode emission with a high peak power of 1.2 W was achieved. Our work is useful for many potential applications of the QCL. [ABSTRACT FROM AUTHOR]

Strigolactones (SLs) are a group of newly identified plant hormones that control plant shoot branching. SL signalling requires the hormone-dependent interaction of DWARF 14 (D14), a probable candidate SL receptor, with DWARF 3 (D3), an F-box component of the Skp-Cullin-F-box (SCF) E3 ubiquitin ligase complex. Here we report the characterization of a dominant SL-insensitive rice (Oryza sativa) mutant dwarf 53 (d53) and the cloning of D53, which encodes a substrate of the SCFD3 ubiquitination complex and functions as a repressor of SL signalling. Treatments with GR24, a synthetic SL analogue, cause D53 degradation via the proteasome in a manner that requires D14 and the SCFD3 ubiquitin ligase, whereas the dominant form of D53 is resistant to SL-mediated degradation. Moreover, D53 can interact with transcriptional co-repressors known as TOPLESS-RELATED PROTEINS. Our results suggest a model of SL signalling that involves SL-dependent degradation of the D53 repressor mediated by the D14-D3 complex. [ABSTRACT FROM AUTHOR]

Proper flower development is essential for sexual reproductive success and the setting of fruits and seeds. The availability of a high quality genome sequence for pineapple makes it an excellent model for studying fruit and floral organ development. In this study, we sequenced 27 different pineapple floral samples and integrated nine published RNA-seq datasets to generate tissue- and stage-specific transcriptomic profiles. Pairwise comparisons and weighted gene co-expression network analysis successfully identified ovule-, stamen-, petal- and fruit-specific modules as well as hub genes involved in ovule, fruit and petal development. In situ hybridization confirmed the enriched expression of six genes in developing ovules and stamens. Mutant characterization and complementation analysis revealed the important role of the subtilase gene AcSBT1.8 in petal development. This work provides an important genomic resource for functional analysis of pineapple floral organ growth and fruit development and sheds light on molecular networks underlying pineapple reproductive organ growth. Wang et al. perform RNA-Seq on pineapple floral samples and also use previously published RNA-Seq datasets to generate tissue- and stage-specific transcriptomic profiles. The authors use weighted gene co-expression network analysis to identify gene networks, bringing insight to underlying pineapple reproductive organ growth. [ABSTRACT FROM AUTHOR]

A correction to the article "DWARF 53 acts as a repressor of strigolactone signalling in rice" that was published in the 2013 issue is presented.