Enhanced Molecularly Imprinted Fluorescent Test Strip for Rapid and Visual Detection of Norfloxacin via a Smartphone.

Paper-based test strips with on-site visual detection have become a hot spot in the field of target detection. Yet, low specific surface area and uneven deposition limit the further application of test strips. Herein, a novel "turn-on" ratio of molecularly imprinted membranes (Eu@CDs-MIMs) was successfully prepared based on a Eu complex-doped polyvinylidene fluoride membrane for the selective, rapid and on-site visual detection of norfloxacin (NOR). The formation of surface-imprinted polymer-containing carbon dots (CDs) improves the roughness and hydrophilicity of Eu@CDs-MIMs. Fluorescence lifetimes and UV absorption spectra verified that the fluorescence enhancement of CDs is based on the synergistic effect of charge transfer and hydrogen bonding between CDs and NOR. The fluorescent test strip showed a linear fluorescent response within the concentration range of 5-50 nM with a limit of detection of 1.35 nM and a short response time of 1 min. In comparison with filter paper-based test strips, Eu@CDs-MIMs exhibit a brighter and more uniform fluorescent color change from red to blue that is visible to the naked eye. Additionally, the applied ratio fluorescent test strip was combined with a smartphone to translate RGB values into concentrations for the visual and quantitative detection of NOR and verified the detection results using high-performance liquid chromatography. The portable fluorescent test strip provides a reliable approach for the rapid, visual, and on-site detection of NOR and quinolones.

Remote passive acoustic signal detection using multi-scale correlation networks and network spectrum distance in marine environment.

Detecting acoustic signals in the ocean is crucial for port and coastal security, but existing methods often require informative priors. This paper introduces a new approach that transforms acoustic signal detection into network characterization using a MCN construction method. The method constructs a network representation of the acoustic signal by measuring pairwise correlations at different time scales. It proposes a network spectrum distance method that combines information geometry and graph signal processing theory to characterize these complex networks. By comparing the spectra of two networks, the method quantifies their similarity or dissimilarity, enabling comparisons of multi-scale correlation networks constructed from different time series data and tracking changes in nonlinear dynamics over time. The effectiveness of these methods is substantiated through comprehensive simulations and real-world data collected from the South China Sea. The results illustrate that the proposed approach attains a significant detection probability of over 90% when the signal-to-noise ratio exceeds -18 dB, whereas existing methods require a signal-to-noise ratio of at least -15 dB to achieve a comparable detection probability. This innovative approach holds promising applications in bolstering port security, facilitating coastal operations, and optimizing offshore activities by enabling more efficient detection of weak acoustic signals.

Heterosis in root microbiota inhibits growth of soil-borne fungal pathogens in hybrid rice.

In nature, plants are colonized by various microbes that play essential roles in their growth and health. Heterosis is a natural genetic phenomenon whereby first-generation hybrids exhibit superior phenotypic performance relative to their parents. It remains unclear whether this concept can be extended to the "hybridization" of microbiota from two parents in their descendants and what benefits the hybrid microbiota might convey. Here, we investigated the structure and function of the root microbiota from three hybrid rice varieties and their parents through amplicon sequencing analysis of bacterial 16S ribosomal DNA (rDNA) and fungal internal transcribed spacer (ITS) regions. We show that the bacterial and fungal root microbiota of the varieties are distinct from those of their parental lines and exhibit potential heterosis features in diversity and composition. Moreover, the root bacterial microbiota of hybrid variety LYP9 protects rice against soil-borne fungal pathogens. Systematic analysis of the protective capabilities of individual strains from a 30-member bacterial synthetic community derived from LYP9 roots indicated that community members have additive protective roles. Global transcription profiling analyses suggested that LYP9 root bacterial microbiota activate rice reactive oxygen species production and cell wall biogenesis, contributing to heterosis for protection. In addition, we demonstrate that the protection conferred by the LYP9 root microbiota is transferable to neighboring plants, potentially explaining the observed hybrid-mediated superior effects of mixed planting. Our findings suggest that some hybrids exhibit heterosis in their microbiota composition that promotes plant health, highlighting the potential for microbiota heterosis in breeding hybrid crops.

Interior and Surface Synergistic Modifications Modulate the SnNb2O6/Ni-Doped ZnIn2S4 S-Scheme Heterojunction for Efficient Photocatalytic H2 Evolution.

Interior and surface synergistic modifications can endow the photocatalytic reaction with tuned photogenerated carrier flow at the atomic level. Herein, a new class of 2D/2D SnNb2O6/Ni-doped ZnIn2S4 (SNO/Ni-ZIS) S-scheme heterojunctions is synthesized by a simple hydrothermal strategy, which was used to evaluate the synergy between interior and surface modifications. Theoretical calculations show that the S-scheme heterojunction boosts the desorption of H atoms for rapid H2 evolution. As a result, 25% SNO/Ni0.4-ZIS exhibits significantly improved PHE activity under visible light, roughly 4.49 and 2.00 times stronger than that of single ZIS and Ni0.4-ZIS, respectively. In addition, 25% SNO/Ni0.4-ZIS also shows superior structural stability. This work provides advanced insight for developing high-performance S-scheme systems from photocatalyst design to mechanistic insight.

The histone deacetylase HDA703 interacts with OsBZR1 to regulate rice brassinosteroid signaling, growth and heading date through repression of Ghd7 expression.

The plant steroid hormones brassinosteroids (BRs) play crucial roles in plant growth and development. The BR signal transduction pathway from perception to the key transcription factors has been well understood in Arabidopsis thaliana and in rice (Oryza sativa); however, the mechanisms conferring BR-mediated growth and flowering remain largely unknown, especially in rice. In this study, we show that HDA703 is a histone H4K8 and H4K12 deacetylase in rice. Hda703 mutants display a typical BR loss-of-function phenotype and reduced sensitivity to brassinolide, the most active BR. Rice plants overexpressing HDA703 exhibit some BR gain-of-function phenotypes dependent on BR biosynthesis and signaling. We also show that HDA703 is a direct target of BRASSINAZOLE-RESISTANT1 (OsBZR1), a primary regulator of rice BR signaling, and HDA703 interacts with OsBZR1 in rice. We further show that GRAIN NUMBER, PLANT HEIGHT, and HEADING DATE 7 (Ghd7), a central regulator of growth, development, and the stress response, is a direct target of OsBZR1. HDA703 directly targets Ghd7 and represses its expression through histone H4 deacetylation. HDA703-overexpressing rice plants phenocopy Ghd7-silencing rice plants in both growth and heading date. Together, our study suggests that HDA703, a histone H4 deacetylase, interacts with OsBZR1 to regulate rice BR signaling, growth, and heading date through epigenetic regulation of Ghd7.

Boosting H2 Production over C60 -Mediated NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S S-Scheme Heterojunction via Enhanced Interfacial Carrier Separation.

Improving greatly the separation efficiency of interfacial charge carrier is a major challenge in photocatalysis. Herein, a new class of C60 -mediated NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S S-scheme heterojunction with enhanced interfacial charge carrier separation is designed and synthesized. The constructed S-scheme heterojunction thermodynamically favors photocatalytic H2 evolution because of the large driving force resulting from its strong redox abilities. As a consequence, the optimum proportion of C60 -mediated NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S S-scheme heterojunction displays comparable H2 evolution activity with a rate of 7825.20 µmol h-1 g-1 under visible light irradiation, which is about 93.05 times, 6.38 times and 2.65 times higher than that of 2% C60 /NH2 -MIL-125(Ti), Zn0.5 Cd0.5 S and 45% NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S, and outperforms the majority of the previously reported MOFs-based photocatalysts. Spectroscopic characterizations and theory calculations indicate that the S-scheme heterojunction can powerfully promote the separation of photogenerated carriers. This work offers a new insight for future design and development of highly active MOFs-based photocatalysts.

Promotion of BR Biosynthesis by miR444 Is Required for Ammonium-Triggered Inhibition of Root Growth.

Rice (Oryza sativa), the staple food for almost half of the world's population, prefers ammonium (NH4 +) as the major nitrogen resource, and while NH4 + has profound effects on rice growth and yields, the underlying regulatory mechanisms remain largely unknown. Brassinosteroids (BRs) are a class of steroidal hormones playing key roles in plant growth and development. In this study, we show that NH4 + promotes BR biosynthesis through miR444 to regulate rice root growth. miR444 targeted five homologous MADS-box transcription repressors potentially forming homologous or heterogeneous complexes in rice. miR444 positively regulated BR biosynthesis through its MADS-box targets, which directly repress the transcription of BR-deficient dwarf 1 (OsBRD1), a key BR biosynthetic gene. NH4 + induced the miR444-OsBRD1 signaling cascade in roots, thereby increasing the amount of BRs, whose biosynthesis and signaling were required for NH4 + -dependent root elongation inhibition. Consistently, miR444-overexpressing rice roots were hypersensitive to NH4 + depending on BR biosynthesis, and overexpression of miR444's target, OsMADS57, resulted in rice hyposensitivity to NH4 + in root elongation, which was associated with a reduction of BR content. In summary, our findings reveal a cross talk mechanism between NH4 + and BR in which NH4 + activates miR444-OsBRD1, an undescribed BR biosynthesis-promoting signaling cascade, to increase BR content, inhibiting root elongation in rice.

Fluorescent polydopamine based molecularly imprinted sensor for ultrafast and selective detection of p-nitrophenol in drinking water.

A highly effective fluorescent molecularly imprinted sensor (F-PDA-MIS) based on fluorescent polydopamine (F-PDA) was successfully synthesized for selective and ultrafast detection of p-nitrophenol (P-NP) in drinking water. F-PDA with abundant surface functional groups has been artfully modified to firstly serve as both fluorescent monomer and functional monomer in the synthesis of a uniform luminous F-PDA-MIS, which can greatly improve the detection efficiency. As expected, F-PDA-MIS had an obvious emission wavelength of 535 nm with the optimal excitation wavelength at 400 nm. Specially, F-PDA-MIS could detect P-NP in the range 100 to 1100 nM with much lower detection limit of 24.2 nM within 120 s compared with other conventional imprinted fluorescent sensors based on pure quantum dots (QDs) or dyes. This excellent test phenomenon is mainly ascribed to the rapid electron transfer between F-PDA and P-NP. Satisfactory recovery of 98.0-104% for mineral water and 98.6-106% for boiling water were obtained with relative standard deviations (RSDs) of 2.7-3.4% and 2.6-3.5% respectively. The detection reliability of F-PDA-MIS was verified by the comparison with high-performance liquid chromatography (HPLC-UV). Consequently, F-PDA as a fluorescence functional monomer has been shown to be a possible strategy to effectively improve the detection limit and shorten response time of the target determination in water..

Biomass derived the V-doped carbon/Bi2O3 composite for efficient photocatalysts.

This work focused on the utilization of biological extract for the preparation of lignin-based carbon composites materials and used in the field of photocatalysis. A straightforward one-step carbonization way has been developed to prepare vanadium-doped lignin-based carbon/Bi2O3 composites photocatalyst by using sodium lignosulfonate as the carbon source and catalyst. The application of lignin as the carbon source to form photocatalyst support tends to control the uniform distribution. At the same time, sodium lignosulfonate as the catalyst could break down the BiVO4 during carbonization process. A series of characterizations demonstrated the BiVO4 was transformed into Bi2O3 and vanadium-doped lignin-based carbon. The possible synthesis process was proposed. Moreover, the novel V-doped carbon/Bi2O3 composites photocatalyst displayed higher photocatalytic activity than bare BiVO4. A possible photocatalytic mechanism was also discussed. This work provided new insight into the lignin-based carbon materials.

Construction of Heterogenous S-C-S MoS2/SnS2/r-GO Heterojunction for Efficient CO2 Photoreduction.

Photocatalytic reduction of CO2 by semiconductors is of great significance in generating value-added fuels. Here, we construct a novel S-C-S heterojunction constituted of MoS2/SnS2/r-GO by a simple solvothermal method. The prepared MoS2/SnS2/r-GO showed significant photoexcitation of photosensitive oxygen (ROS) by electron spin resonance spectroscopy, demonstrating that superoxide radicals (•O2-), pores, and hydroxyl radicals (•OH) are the main active species. The constructed S-C-S heterojunction has a multilevel electron transport mechanism and synergistic effect, which provides the possibility of producing more organic fuel. The photocatalytic materials were characterized by XRD, XPS, SEM, TEM, PL, etc. As a result, the atomic layer MoS2/SnS2/r-GO heterojunction exhibited a CO formation rate of 68.53 µmol g-1 h-1 and a CH4 formation rate of 50.55 µmol g-1 h-1, respectively. This work opens up new prospects for the formation of heterojunctions of chalcogenide transition-metal sulfides.

Bioinspired synthesis of SiO2/pDA-based nanocomposite-imprinted membranes with sol-gel imprinted layers for selective adsorption and separation applications.

Inspired by the biomimetic membrane modification technique of polydopamine (pDA), SiO2/pDA-based nanocomposite-imprinted membranes (SpIMs) with high selectivity and stability have been successfully synthesized. Herein, tetracycline (TC) was used as a template molecule and instead of constructing imprinted polymers onto pristine membrane surfaces, a versatile pDA-modified strategy was initially conducted on the membrane surfaces followed by the reformative sol-gel imprinting technique. Moreover, largely enhanced TC-rebinding capacity (45.95 mg g-1), permselectivity of TC (separation factors more than 11.5) and structural stability (maintained 93% of the maximum adsorption capacity after 11 cycling operations) could be easily achieved because of the construction of membrane-based multilevel nanocomposite surfaces. These results strongly illustrated that the incorporation of pDA-based sol-gel imprinted polymers into molecularly imprinted membranes could result in both high rebinding capacity and excellent permselectivity. All synthesis processes were carried out at low temperatures and ordinary pressures, which is energy-efficient and environmentally friendly for large-scale applications.

Synthesis of molecularly imprinted dye-silica nanocomposites with high selectivity and sensitivity: Fluorescent imprinted sensor for rapid and efficient detection of τ-fluvalinate in vodka.

An imprinted fluorescent sensor was fabricated based on SiO2 nanoparticles encapsulated with a molecularly imprinted polymer containing allyl fluorescein. High fluorine cypermethirin as template molecules, methyl methacrylate as functional monomer, and allyl fluorescein as optical materials synthesized a core-shell fluorescent molecular imprinted sensor, which showed a high and rapid sensitivity and selectivity for the detection of τ-fluvalinate. The sensor presented appreciable sensitivity with a limit of 13.251 nM, rapid detection that reached to equilibrium within 3 min, great linear relationship in the relevant concentration range from 0 to 150 nM, and excellent selectivity over structural analogues. In addition, the fluorescent sensor demonstrated desirable regeneration ability (eight cycling operations). The molecularly imprinted polymers ensured specificity, while the fluorescent dyes provided the stabile sensitivity. Finally, an effective application of the sensor was implemented by the detection of τ-fluvalinate in real samples from vodka. The molecularly imprinted fluorescent sensor showed a promising potential in environmental monitoring and food safety.

Fluorescent molecularly imprinted nanoparticles for selective and rapid detection of ciprofloxacin in aquaculture water.

Fluorescent molecularly imprinted nanoparticles have shown great promise in the field of chemical analysis or detection because of their high stability, selectivity, and sensitivity. In this work, fluorescent molecularly imprinted nanoparticles were synthesized by precipitation polymerization employing fluorescein isothiocyanate as luminescent material, which could efficiently and rapidly detect ciprofloxacin in water samples. The prepared fluorescent molecularly imprinted nanoparticles had remarkable stability and good selectivity with the method detection limit low to 4.04 nm. In addition, the fluorescent-imprinted nanoparticles were capable of identifying the target with high detection efficiency and were applied to the detection of ciprofloxacin in aquaculture water with complex composition. All these would provide the direct monitoring of ciprofloxacin in environmental water with a promising fluorescent imprinting strategy.

Synthesis of Fe3O4/C with Cauliflower-Like BiVO4 for Improved Separation Efficiency of Charge Carriers and Photocatalytic Activity.

Fe3O4/C/BiVO4 composite photocatalyst was fabricated successfully by a simple approach using yeast as a carbon source. Fe3O4/C/BiVO4 sample exhibited higher efficiency for photocatalytic degradation of tetracycline (TC) as compared to pure BiVO4 under visible light. In addition, after five recycles of photodegradation of TC, Fe3O4/C/BiVO4 showed a slight loss in photocatalytic activity, which confirmed its stability and long-time reusability. The photocatalytic mechanism was studied by active species trapping experiments, which revealed that the holes (h+) and superoxide radical (˙O-2) played a key role in TC degradation. Moreover, photocatalyst could be easily recycled by an external magnetic field and reused without any loss in photocatalytic activity. This work provides a simple, eco-friendly and exemplary strategy for improving photodegradation activity of BiVO4-based photocatalyst.

A polydopamine-based molecularly imprinted polymer on nanoparticles of type SiO2@rGO@Ag for the detection of λ-cyhalothrin via SERS.

A new method is described for the determination of the pesticide λ-cyhalothrin (LC). It combines SERS detection with molecular imprinting and largely improves selectivity. A multilayer surface imprinted nanocomposite was synthesized in two steps on a nanostructure of type SiO2@rGO@Ag acting as a substrates. Firstly, the surface of the SiO2@rGO@Ag composite was modified with self-polymerized dopamine. Secondly, surface-initiated polymerization was carried out to prepare a molecularly imprinted polymer (MIP) using LC as the template. The use of this SiO2@rGO@Ag-MIP allows for excellent SERS based detection and has high selectivity for LC. The Raman intensity and LC concentration present perfect linear relationship between 10-5 to 10-9 mol L-1 and the detection limit is 3.8×10-10 mol L-1. All the procedures are conducted in aqueous or ethanol solution. Graphical abstract Schematic of a new method for determination of the pesticide λ-cyhalothrin. It combines SERS detection with molecular imprinting and largely improves selectivity. A multilayer surface imprinted nanocomposite was synthesized in two steps on a nanostructure of type SiO2@rGO@Ag acting as a substrates.

Efficient Convex Optimization for Energy-Based Acoustic Sensor Self-Localization and Source Localization in Sensor Networks.

The energy reading has been an efficient and attractive measure for collaborative acoustic source localization in practical application due to its cost saving in both energy and computation capability. The maximum likelihood problems by fusing received acoustic energy readings transmitted from local sensors are derived. Aiming to efficiently solve the nonconvex objective of the optimization problem, we present an approximate estimator of the original problem. Then, a direct norm relaxation and semidefinite relaxation, respectively, are utilized to derive the second-order cone programming, semidefinite programming or mixture of them for both cases of sensor self-location and source localization. Furthermore, by taking the colored energy reading noise into account, several minimax optimization problems are formulated, which are also relaxed via the direct norm relaxation and semidefinite relaxation respectively into convex optimization problems. Performance comparison with the existing acoustic energy-based source localization methods is given, where the results show the validity of our proposed methods.

A Signaling Cascade from miR444 to RDR1 in Rice Antiviral RNA Silencing Pathway.

Plant RNA-DEPENDENT RNA POLYMERASE1 (RDR1) is a key component of the antiviral RNA-silencing pathway, contributing to the biogenesis of virus-derived small interfering RNAs. This enzyme also is responsible for producing virus-activated endogenous small interfering RNAs to stimulate the broad-spectrum antiviral activity through silencing host genes. The expression of RDR1 orthologs in various plants is usually induced by virus infection. However, the molecular mechanisms of activation of RDR1 expression in response to virus infection remain unknown. Here, we show that a monocot-specific microRNA, miR444, is a key factor in relaying the antiviral signaling from virus infection to OsRDR1 expression. The expression of miR444 is enhanced by infection with Rice stripe virus (RSV), and overexpression of miR444 improves rice (Oryza sativa) resistance against RSV infection accompanied by the up-regulation of OsRDR1 expression. We further show that three miR444 targets, the MIKC(C)-type MADS box proteins OsMADS23, OsMADS27a, and OsMADS57, form homodimers and heterodimers between them to repress the expression of OsRDR1 by directly binding to the CArG motifs of its promoter. Consequently, an increased level of miR444 diminishes the repressive roles of OsMADS23, OsMADS27a, and OsMADS57 on OsRDR1 transcription, thus activating the OsRDR1-dependent antiviral RNA-silencing pathway. We also show that overexpression of miR444-resistant OsMADS57 reduced OsRDR1 expression and rice resistance against RSV infection, and knockout of OsRDR1 reduced rice resistance against RSV infection. In conclusion, our results reveal a molecular cascade in the rice antiviral pathway in which miR444 and its MADS box targets directly control OsRDR1 transcription.

Preparation of a self-cleanable molecularly imprinted sensor based on surface-enhanced Raman spectroscopy for selective detection of R6G.

Novel molecularly imprinted polymers (MIPs) based on the technique of surface-enhanced Raman scattering (SERS) were successfully prepared. Firstly, ZnO nanorods were fabricated with Ag by reduction of Ag+ on the surface of the ZnO nanorods. Then, ZnO/Ag heterostructures were used as the substrate, rhodamine 6G was used as the template molecule, acrylamide was used as the functional monomer, ethylene glycol dimethacrylate was used as the cross-linker, and 2,2'-azobis(2-methylpropionitrile) was used as the initiator to prepare the ZnO/Ag MIPs (ZOA-MIPs). Through characterization analysis, it was proved that the novel ZOA-MIPs exhibited excellent SERS properties and selectivity. Under the optimal conditions, there was a good linear relationship (R 2 = 0.996) between the Raman signal (at 1654 cm-1) and the concentration of the templates, and the detection limit was 10-13 mol L-1. It was also proved that the ZOA-MIPs had the property of self-cleaning, resulting in good reusability. It is envisaged that the sensitivity of SERS coupled with the selectivity of MIPs could result in a promising chemosensor for practical applications.

Near-infrared light-responsive nanoparticles with thermosensitive yolk-shell structure for multimodal imaging and chemo-photothermal therapy of tumor.

Thermosensitive yolk-shell nanoparticles were developed as remote-controlled targeting drug delivery platform for multimodal imaging and combined therapy of cancer. The nanoparticles were fabricated using magnetic Fe3O4 nanoparticles as photothermal cores, thermo-responsive poly(N-isopropylacrylamide)-co-1-Vinyl-2-pyrrolidone p(NIPAM-co-NVP) as shells (Fe3O4-PNIPAM), with a hollow space between the two layers for loading of chemotherapeutic drug. The magnetic iron oxide nanoparticle cores could absorb and transform light to heat efficiently upon the irradiation of near infrared (NIR) laser, resulting in the shrink of the PNIPAM shell and the release of chemo-drugs. In vivo fluorescence/photoacoustic images demonstrated that Fe3O4-PNIPAM nanoparticles could accumulate in the tumor after intravenous injection. Upon the irradiation of the NIR laser, DOX-Fe3O4-PNIPAM nanoparticles exhibited outstanding synergistic effect. The tumor inhibition rate increased from 40.3% (DOX-Fe3O4-PNIPAM alone) and 65.2% (Fe3O4-PNIPAM +NIR) to 91.5%. The results demonstrated that the NIR-responsive nanocarrier offers a novel strategy for cancer theranostics and combined therapy of cancer.

Construction of vesicle CdSe nano-semiconductors photocatalysts with improved photocatalytic activity: Enhanced photo induced carriers separation efficiency and mechanism insight.

Visible-light-driven photocatalysis as a green technology has attracted a lot of attention due to its potential applications in environmental remediation. Vesicle CdSe nano-semiconductor photocatalyst are successfully prepared by a gas template method and characterized by a variety of methods. The vesicle CdSe nano-semiconductors display enhanced photocatalytic performance for the degradation of tetracycline hydrochloride, the photodegradation rate of 78.824% was achieved by vesicle CdSe, which exhibited an increase of 31.779% compared to granular CdSe. Such an exceptional photocatalytic capability can be attributed to the unique structure of the vesicle CdSe nano-semiconductor with enhanced light absorption ability and excellent carrier transport capability. Meanwhile, the large surface area of the vesicle CdSe nano-semiconductor can increase the contact probability between catalyst and target and provide more surface-active centers. The photocatalytic mechanisms are analyzed by active species quenching. It indicates that h+ and O2- are the main active species which play a major role in catalyzing environmental toxic pollutants. Simultaneously, the vesicle CdSe nano-semiconductor had high efficiency and stability.