Construction of SNP fingerprints and genetic diversity analysis of radish (Raphanus sativus L.).

Radish (Raphanus sativus L.) is a vegetable crop with economic value and ecological significance in the genus Radish, family Brassicaceae. In recent years, developed countries have attached great importance to the collection and conservation of radish germplasm resources and their research and utilization, but the lack of population genetic information and molecular markers has hindered the development of the genetic breeding of radish. In this study, we integrated the radish genomic data published in databases for the development of single-nucleotide polymorphism (SNP) markers, and obtained a dataset of 308 high-quality SNPs under strict selection criteria. With the support of Kompetitive Allele-Specific PCR (KASP) technology, we screened a set of 32 candidate core SNP marker sets to analyse the genetic diversity of the collected 356 radish varieties. The results showed that the mean values of polymorphism information content (PIC), minor allele frequency (MAF), gene diversity and heterozygosity of the 32 candidate core SNP markers were 0.32, 0.30, 0.40 and 0.25, respectively. Population structural analysis, principal component analysis and genetic evolutionary tree analysis indicated that the 356 radish materials were best classified into two taxa, and that the two taxa of the material were closely genetically exchanged. Finally, on the basis of 32 candidate core SNP markers we calculated 15 core markers using a computer algorithm to construct a fingerprint map of 356 radish varieties. Furthermore, we constructed a core germplasm population consisting of 71 radish materials using 32 candidate core markers. In this study, we developed SNP markers for radish cultivar identification and genetic diversity analysis, and constructed DNA fingerprints, providing a basis for the identification of radish germplasm resources and molecular marker-assisted breeding as well as genetic research.

Flexible Transparent Electrode Based on Ag Nanowires: Ag Nanoparticles Co-Doped System for Organic Light-Emitting Diodes.

Flexible organic light-emitting diodes (FOLEDs) have promising potential for future wearable applications because of their exceptional mechanical flexibility. Silver nanowire (Ag NW) networks are the most promising candidates to replace indium tin oxide (ITO), which is limited by its poor bendability. In this study, three different methods including methanol impregnation, argon plasma treatment, and ultraviolet radiation were used to reduce the junction resistance of Ag NWs to optimize the flexible transparent electrodes (FTEs); which were prepared using Ag NWs and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS). Then, the optoelectronic properties of the FTEs were further improved by using a co-doped system of silver nanowires and silver nanoparticles (Ag NPs), the structure of which consisted of PET/Ag NWs: Ag NPs/PEDOT: PSS/DMSO. The largest FOM value of 1.42 × 10-2 ohm-1 and a low sheet resistance value of 13.86 ohm/sq were obtained using the optimized FTEs. The prepared FOLED based on the optimized FTEs had a luminous efficiency of 6.04 cd/A and a maximum EQE of 1.92%, and exhibited no observed decline in efficiency when reaching maximum luminance. After 500 bending tests, the luminance still reached 82% of the original value. It is demonstrated that the FTEs prepared via the co-doped system have excellent optoelectronic properties as well as high mechanical stability.

The Optimization of Hole Injection Layer in Organic Light-Emitting Diodes.

Organic light-emitting diodes (OLEDs) are widely recognized as the forefront technology for displays and lighting technology. Now, the global OLED market is nearly mature, driven by the rising demand for superior displays in smartphones. In recent years, numerous strategies have been introduced and demonstrated to optimize the hole injection layer to further enhance the efficiency of OLEDs. In this paper, different methods of optimizing the hole injection layer were elucidated, including using a suitable hole injection material to minimize the hole injection barrier and match the energy level with the emission layer, exploring new preparation methods to optimize the structure of hole injection layer, and so on. Meanwhile, this article can help people to understand the current research progress and the challenges still faced in relation to the hole injection layer in OLEDs, providing future research directions to enhance the properties of OLEDs.

A comprehensive strategy for prediction and quality evaluation of standardized planting herbs based on plant metabolomics coupled with extreme learning machine: Astragali Radix as an example.

INTRODUCTION: Standardizing the planting process is an effective way to control the quality stability of herbal resources, which are susceptible to external environmental factors (e.g., moisture, soil, etc.). However, how to scientifically and comprehensively assess the effects of standardized planting on plant quality and quickly test unknown samples has not been addressed. OBJECTIVE: The aim of this study was to determine and compare the metabolite levels of herbs before and after standardized planting, to quickly distinguish their sources, and to evaluate their quality, using the typical herb Astragali Radix (AR) as an example. METHODS: In this study, an efficient strategy using liquid chromatography-mass spectrometry (LC-MS) based on plant metabolomics combined with extreme learning machine (ELM) has been developed to efficiently distinguish and predict AR after standardized planting. Moreover, a comprehensive multi-index scoring method has been developed for the comprehensive evaluation of the quality of AR. RESULTS: The results confirmed that AR after standardized planting was significantly differentiated, with a relatively stable content of 43 differential metabolites, mainly including flavonoids. An ELM model was established based on LC-MS data, and the accuracy in predicting unknown samples could reach more than 90%. As expected, higher total scores were obtained for AR after standardized planting, indicating much better quality. CONCLUSION: A dual system for evaluating the impact of standardized planting on the quality of plant resources has been established, which will significantly contribute to innovation in the quality evaluation of medicinal herbs and support the selection of optimal planting conditions.

Prevalence and Influencing Factors of Medical Dissatisfaction Experiences in Chinese Hospitals: A Cross-Sectional Study.

PURPOSE: To explore the influencing factors of medical dissatisfaction experiences from the perspectives of patients, and provide corresponding strategies for its prevention. PATIENTS AND METHODS: Using multistage random sampling, 43 hospitals in three provinces of China were surveyed using a self-designed questionnaire. There were 2065 valid questionnaires analyzed in our study. RESULTS: 46.9% (n = 934) of participants had experienced medical dissatisfaction in the past year, mainly due to poor service quality, cumbersome procedures and high medical costs. There were statistically significant differences in the medical dissatisfaction experiences for these patients with different ages, marital status and levels of education (P<0.05). According to structural equation modelling, health education and media reports had a positive and indirect influence (standardized coefficient = 0.046) on medical dissatisfaction experiences, while there was a negative correlation (standardized coefficient = -0.399) between patients' social recognition and medical dissatisfaction experiences. Also, our results also found that social relationships had a negative and indirect impact (standardized coefficient = -0.166) on medical dissatisfaction experiences. Besides, health education and media reports had a negative impact (standardized coefficient = -0.115) on patients' social recognition, while social relationships have a positive effect (standardized coefficient = 0.416) on patients' social recognition. CONCLUSION: Health education and media reports and social relationships, as antecedent variables, have an indirect effect on inducing the medical dissatisfaction experiences of patients. In addition, patients' social recognition was an intermediate variable in inducing the medical dissatisfaction of patients.

Transition-Metal Oxides/Carbides@Carbon Nanotube Composites as Multifunctional Electrocatalysts for Challenging Oxidations and Reductions.

The rapid development of renewable-energy technologies such as water splitting, rechargeable metal-air batteries, and fuel cells requires highly efficient electrocatalysts capable of the oxygen-reduction reaction (ORR) and the oxygen-evolution reaction (OER). Herein, we report a facile sonication-driven synthesis to deposit the molecular manganese vanadium oxide precursor [Mn4 V4 O17 (OAc)3 ]3- on multiwalled carbon nanotubes (MWCNTs). Thermal conversion of this composite at 900 °C gives nanostructured manganese vanadium oxides/carbides, which are stably linked to the MWCNTs. The resulting composites show excellent electrochemical reactivity for ORR and OER, and significant reactivity enhancements compared with the precursors and a Pt/C reference are reported. Notably, even under harsh acidic conditions, long-term OER activity at low overpotential is reported. In addition, we report exceptional activity of the composites for the industrially important Cl2 evolution from an aqueous HCl electrolyte. The new composite material shows how molecular deposition routes leading to highly active and stable multifunctional electrocatalysts can be developed. The facile design could in principle be extended to multiple catalyst classes by tuning of the molecular metal oxide precursor employed.

Manganese Vanadium Oxide-N-Doped Reduced Graphene Oxide Composites as Oxygen Reduction and Oxygen Evolution Electrocatalysts.

The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are key catalytic processes for sustainable energy technologies, such as water electrolysis or fuel cells. Here, a novel metal oxide-nanostructured carbon composite is reported, which acts as OER and ORR electrocatalyst under technologically relevant conditions. A facile synthetic process allows the deposition of a molecular manganese vanadium oxide precursor, [Mn4V4O17(OAc)3]3-, on reduced graphene oxide. Simultaneously, the precursor is converted into insoluble nanostructured solid-state Mn-V-oxide catalysts. Control of the synthetic conditions allows tuning of the electrocatalytic properties of the composites, leading to excellent and stable electrochemical reactivity. The electrocatalytic ORR and OER activity was evaluated in alkaline aqueous electrolyte and showed performance comparable with commercial Pt/C electrocatalysts. The study thus demonstrates how polyoxometalate precursors based on earth-abundant elements can be deposited on nanostructured carbon to give high-performance OER/ORR catalysts for alkaline water electrolysis. A new class of composite catalysts can in future be accessed by a facile fabrication route.

Hypermutation-induced in vivo oxidative stress resistance enhances Vibrio cholerae host adaptation.

Bacterial pathogens are highly adaptable organisms, a quality that enables them to overcome changing hostile environments. For example, Vibrio cholerae, the causative agent of cholera, is able to colonize host small intestines and combat host-produced reactive oxygen species (ROS) during infection. To dissect the molecular mechanisms utilized by V. cholerae to overcome ROS in vivo, we performed a whole-genome transposon sequencing analysis (Tn-seq) by comparing gene requirements for colonization using adult mice with and without the treatment of the antioxidant, N-acetyl cysteine. We found that mutants of the methyl-directed mismatch repair (MMR) system, such as MutS, displayed significant colonization advantages in untreated, ROS-rich mice, but not in NAC-treated mice. Further analyses suggest that the accumulation of both catalase-overproducing mutants and rugose colony variants in NAC- mice was the leading cause of mutS mutant enrichment caused by oxidative stress during infection. We also found that rugose variants could revert back to smooth colonies upon aerobic, in vitro culture. Additionally, the mutation rate of wildtype colonized in NAC- mice was significantly higher than that in NAC+ mice. Taken together, these findings support a paradigm in which V. cholerae employs a temporal adaptive strategy to battle ROS during infection, resulting in enriched phenotypes. Moreover, ΔmutS passage and complementation can be used to model hypermuation in diverse pathogens to identify novel stress resistance mechanisms.

Gluconeogenic growth of Vibrio cholerae is important for competing with host gut microbiota.

PURPOSE: The gastrointestinal tract is home to thousands of commensal bacterial species. Therefore, competition for nutrients is paramount for successful bacterial pathogen invasion of intestinal ecosystems. The human pathogen Vibrio cholerae, the causative agent of the severe diarrhoeal disease, cholera, is able to colonize the small intestine, which is protected by mucus. However, it is unclear which metabolic pathways or nutrients V. cholerae utilizes during intestinal colonization and growth. METHODOLOGY: In this study, we investigated the effect of various metabolic key genes, including those involved in the gluconeogenesis pathway, on V. cholerae physiology and in vivo colonization. RESULTS: We found that gluconeogenesis is important for infant mouse colonization. Growth assays showed that mutations in the key components of gluconeogenesis pathway, PpsA and PckA, lead to a growth defect in a minimal medium supplemented with mucin as a carbon source. Furthermore, the ppsA/pckA mutants colonized poorly in the adult mouse intestine, particularly when more gut commensal flora are present. CONCLUSION: Gluconeogenesis biosynthesis is important for the successful colonization of V. cholerae in a niche that is full of competing microbiota.

Synthesis, Structure, and Antibacterial Activity of a Thallium(III)-Containing Polyoxometalate, [Tl2{B-ß-SiW8O30(OH)}2]12.

We have synthesized and structurally characterized the first discrete thallium-containing polyoxometalate, [Tl2{B-ß-SiW8O30(OH)}2]12- (1). Polyanion 1 was characterized in the solid-state and shown to be solution-stable by 203/205Tl NMR, electrospray ionization mass spectrometry, and electrochemical studies. The antibacterial activity of 1 was also investigated.

Mixed-Valent Mn16-Containing Heteropolyanions: Tuning of Oxidation State and Associated Physicochemical Properties.

The two 16-manganese-containing, Keggin-based 36-tungsto-4-silicates [Mn(III)10Mn(II)6O6(OH)6(PO4)4(A-α-SiW9O34)4](28-) (1) and [Mn(III)4Mn(II)12(OH)12(PO4)4(A-α-SiW9O34)4](28-) (2) have been prepared by reaction of the trilacunary Keggin precursor [A-α-SiW9O34](10-) with either Mn(OOCCH3)3·2H2O (for 1) or MnCl2·4H2O (for 2), in aqueous phosphate solution at pH 9. Polyanions 1 and 2 comprise mixed-valent, cationic {Mn(III)10Mn(II)6O6(OH)6}(24+) and {Mn(III)4Mn(II)12(OH)12}(24+) cores, respectively, encapsulated by four phosphate groups and four {SiW9} units in a tetrahedral fashion. Both polyanions were structurally and compositionally characterized by single-crystal XRD, IR, thermogravimetric analysis, and X-ray absorption spectroscopy. Furthermore, studies were performed probing the magnetic, electrochemical, oxidation catalytic, and Li-ion battery performance of 1 and 2.

Platinum-Containing Polyoxometalates: syn- and anti-[Pt(II)2(α-PW11O39)2](10-) and Formation of the Metal-Metal-Bonded di-Pt(III) Derivatives.

The first examples of dimeric, di-Pt(II) -containing heteropolytungstates are reported. The two isomeric di-platinum(II)-containing 22-tungsto-2-phosphates [anti-Pt(II)2(α-PW11O39)2](10-) (1 a) and [syn-Pt(II)2(α-PW11O39)2](10-) (2 a) were synthesized in aqueous pH 3.5 medium using one-pot procedures. Polyanions 1 a and 2 a contain a core comprising two face-on PtO4 units, with a Pt⋅⋅⋅Pt distance of 2.9-3 Å. Both polyanions were investigated by single-crystal XRD, IR, TGA, UV/Vis, (31) P NMR, ESI-MS, CID-MS/MS, electrochemistry, and DFT. On the basis of DFT and electrochemistry, we demonstrated that the {Pt2(II)} moiety in 1 a and 2 a can undergo fully reversible two-electron oxidation to {Pt2(III)}, accompanied by formation of a single Pt-Pt bond. Hence we have discovered the novel subclass of Pt(III)-containing heteropolytungstates.

Ti2-Containing 18-Tungsto-2-Arsenate(III) Monolacunary Host and the Incorporation of a Phenylantimony(III) Guest.

The novel Ti2-containing, sandwich-type 18-tungsto-2-arsenate(III) [(Ti(IV)O)2(α-As(III)W9O33)2](14-) (1) was successfully synthesized by the reaction of [TiO](2+) species with [α-As(III)W9O33](9-). The monolacunary polyanion 1 is solution-stable, and a further reaction with 1 equiv of phenylantimony(III) dichloride resulted in [C6H5Sb(III)(Ti(IV)O)2(α-As(III)W9O33)2](12-) (2). Both polyanions 1 and 2 were structurally characterized in the solid state and solution. Electrochemical studies were also performed on both polyanions.

Facile decoration of Au nanoparticles on CdS nanorods by polyoxometalate with enhanced photocatalytic activities toward hydrogen evolution.

The tri-component hybrid CdS nanorods (NRs)/Au nanoparticles (NPs)@polyoxometalate (POM) was successfully prepared by a facile, efficient and green method. The structural properties and component analysis were studied by Transmission electron microscopy (TEM), X-ray Diffraction (XRD) and UV-Vis spectra. The POMs sever as not only reductant and bridge molecules, but also as co-catalyst to play an important role in the photocatalytic process. The as-prepared nanohybrid shows obviously enhanced photocatalytic activity toward photocatalytic evolution of hydrogen.