Identification of signature of gene expression in biliary atresia using weighted gene co-expression network analysis.

Biliary atresia (BA) is the most common cause of obstructive jaundice during the neonatal period. This study aimed to identify gene expression signature in BA. The datasets were obtained from the Gene Expression Omnibus database. Weighted gene co-expression network analysis identified a critical module associated with BA, whereas Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed the functions of the essential modules. The high-connectivity genes in the most relevant module constructed protein-protein interaction networks via the string website and Cytoscape software. Hub genes screened by lasso regression consisted of a disease classification model using the randomforest method. Receiver operating characteristic curves were used to assess models' sensitivity and specificity and the model was verified using the internal and external validation sets. Ten gene modules were constructed by WGCNA, of which the brown module had a strong positive correlation with BA, comprising 443 genes. Functional enrichment analysis revealed that module genes were mainly involved in biological processes, such as extracellular matrix organization, cell adhesion, inflammatory response, and the Notch pathway (P < .001), whereas these genes were involved in the metabolic pathways and cell adhesion molecules (P < .001). Thirty-nine high-connectivity genes in the brown module constructed protein-protein interaction networks. keratin 7 (KRT7) and C-X-C motif chemokine ligand 8 (CXCL8) were used to construct a diagnostic model that had an accuracy of 93.6% and the area under the receiver operating curves for the model was 0.93. The study provided insight into the signature of gene expression and possible pathogenesis of BA; furthermore, it identified that the combination of KRT7 and CXCL8 could be a potential diagnostic model for BA.

Single-Cell Transcriptome Analysis Decipher New Potential Regulation Mechanism of ACE2 and NPs Signaling Among Heart Failure Patients Infected With SARS-CoV-2.

Aims: COVID-19 patients with comorbidities such as hypertension or heart failure (HF) are associated with poor clinical outcomes. The cellular distribution of Angiotensin-converting enzyme 2 (ACE2), the critical enzyme for SARS-CoV-2 infection, in the human heart is unknown. We explore the underlying mechanism that leads to increased susceptibility to SARS-CoV-2 in patients with cardiovascular diseases and patients of cardiac dysfunction have increased risk of multi-organ injury compared with patients of normal cardiac function. Methods and Results: We analyzed single-cell RNA sequencing (scRNA-seq) data in both normal and failing hearts. The results demonstrated that ACE2 is present in cardiomyocytes (CMs) and non-CMs, while the number of ACE2-postive (ACE2+) CMs and ACE2 gene expression in these CMs are significantly increased in the failing hearts. Interestingly, both brain natriuretic peptides (BNP) and atrial natriuretic peptide (ANP) are significantly up-regulated in the ACE2+ CMs, which is consistent with other studies that ACE2, ANP, and BNP increased in HF patients. We found that genes related to virus entry, virus replication and suppression of interferon-gamma signaling are all up-regulated in failing CMs, and the increase was significantly higher in ACE2+ CMs, suggesting that these CMs may be more vulnerable to virus infection. As the level of expression of both ACE2 and BNP in CMs were up-regulated, we further performed retrospective analysis of the plasma BNP levels and clinical outcomes of 91 COVID-19 patients from a single-center. Patients with higher plasma BNP were associated with significantly higher mortality and expression levels of inflammatory and infective markers. Conclusion: In the failing heart, the upregulation of ACE2 and virus infection associated genes could potentially facilitate SARS-CoV-2 virus entry and replication in these vulnerable cardiomyocyte subsets. COVID-19 patients with higher plasma BNP levels had poorer clinical outcomes. These observations may allude to a potential regulatory association between ACE2 and BNP in mediating myocarditis associated with COVID-19.

[Biochemical analysis between common type and critical type of COVID-19 and clinical value of neutrophil/lymphocyte ratio].

OBJECTIVE: To identify the key biochemical indicators that affect the clinical type and outcomes of COVID-19 patients and explore the application of neutrophil/lymphocyte ratio (NLR) in COVID-19. METHODS: Ninety-three patients with confirmed diagnosis of COVID-19 admitted in Ezhou Central Hospital from February to April in 2020 were analyzed. Among them, 43 patients were selected from Intensive Care Unit (ICU) with the diagnosis of critical type of COVID-19, and 50 cases of common type were selected from the Department of Respiratory Medicine. The baseline data, blood routine test and biochemical indexes of the patients were collected on the first day of admission. NLRs of the patients were calculated, and COX survival analysis according to the NLR 4-category method was performed. The patients' outcomes were analyzed with receiver operating curves (ROCs). The patients were divided into two groups according to NLR cutoff value for comparison of the biochemical indexes. Based on the patients' outcomes, NLR cutoff value classification and clinical classification, multiple binary logistics regression was performed to screen the key variables and explore their significance in COVID-19. RESULTS: The NLR four-category method was not applicable for prognostic evaluation of the patients. The cut-off value of NLR for predict the prognosis of COVID-19 was 11.26, with a sensitivity of 0.903 and a specificity of 0.839; the laboratory indicators of the patients with NLR < 11.26 were similar to those in patients of the common type; the indicators were also similar between patients with NLR≥11.26 and those with critical type COVID-19. NLR, WBC, NEUT, PCT, DD, BUN, TNI, BNP, and LDH had significant effects on the clinical classification and outcome of the patients (P < 0.05); Cr, Ca, PH, and Lac had greater impact on the outcome of the patients (P < 0.05), while Na, PCO2 had greater impact on the clinical classification of the patients (P < 0.05). CONCLUSIONS: NLR can be used as an important reference for clinical classification, prognostic assessment, and biochemical abnormalities of COVID-19. Patients of critical type more frequently have bacterial infection with more serious inflammatory reactions, severer heart, lung and kidney damages, and much higher levels of DD and LDH than those of the common type. NLR, NEUT, DD, TNI, BNP, LDH, Ca, PCT, PH, and Lac have obvious influence on the prognosis of COVID-19 and should be observed dynamically.

Single-cell Transcriptome Analysis Indicates New Potential Regulation Mechanism of ACE2 and NPs signaling among heart failure patients infected with SARS-CoV-2.

BACKGROUND: COVID-19 patients with comorbidities such as hypertension or heart failure (HF) are associated with poor clinical outcomes. Angiotensin-converting enzyme 2 (ACE2), the critical enzyme for SARS-CoV-2 infection, is broadly expressed in many organs including heart. However, the cellular distribution of ACE2 in the human heart, particularly the failing heart is unknown. METHODS: We analyzed single-cell RNA sequencing (scRNA-seq) data in both normal and failing hearts, and characterized the ACE2 gene expression profile in various cell subsets, especially in cardiomyocyte subsets, as well as its interaction with gene networks relating to various defense and immune responses at the single cell level. RESULTS: The results demonstrated that ACE2 is present in cardiomyocytes (CMs), endothelial cells, fibroblasts and smooth muscle cells in the heart, while the number of ACE2-postive (ACE2+) CMs and ACE2 gene expression in these CMs are significantly increased in the failing hearts. Interestingly, both brain natriuretic peptides (BNP) and atrial natriuretic peptide (ANP) are significantly up-regulated in the ACE2+ CMs. Further analysis shows that ANP, BNP and ACE2 may form a negative feedback loop with a group of genes associated with the development of heart failure. To our surprise, we found that genes related to virus entry, virus replication and suppression of interferon-gamma（IFN-γ）signaling are all up-regulated in CMs in failing hearts, and the increases were significantly higher in ACE2+ CMs as compared with ACE2 negative (ACE2-) CMs, suggesting that these ACE2+ CMs may be more vulnerable to virus infection. Since ACE2 expression is correlated with BNP expression, we further performed retrospective analysis of the plasma BNP levels and clinic outcome of 91 COVID-19 patients from a single-center. Patients with higher plasma BNP were associated with significantly higher mortality rate and expression levels of inflammatory and infective markers such as procalcitonin and C-reactive protein. CONCLUSION: In the failing heart, the upregulation of ACE2 and virus infection associated genes, as well as the increased expression of ANP and BNP could facilitate SARS-CoV-2 virus entry and replication in these vulnerable cardiomyocyte subsets. These findings may advance our understanding of the underlying molecular mechanisms of myocarditis associated with COVID-19.

Preliminary structure and bioactivities of polysaccharide SMWP-U&E isolated from Salvia miltiorrhiza Bunge Residue.

The fractional polysaccharide SMWP-U&E was isolated from Salvia miltiorrhiza residue. SMWP-U&E consists of 91.40% carbohydrates and has an average molecular weight of 5.07 × 105 Da. The polysaccharides are mainly composed of arabinose (Ara), fructose (Fru), mannose (Man), glucose (Glc), and galactose (Gal), and their mole percentages are 3.72%, 4.11%, 6.18%, 32.08% and 53.91%, respectively. When effected on weaned piglets, 1.5 g/kg SMWP-U&E supplementation significantly increased the villus height to crypt depth ratio in ileum. PCR-denaturing gradient gel electrophoresis and qRT-PCR results indicated that SMWP-U&E supplementation could change the density of intestinal microbiota and the populations of Lactobacillus and Escherichia coli in jejunum, ileum, caecum, and colon. The supplementation also increased contents of IgA, IgG, IgM, IL-2, IFN-γ, and IL-10; promoted T-AOC and SOD activities; and reduced MDA level in the serum. These findings suggest that SMWP-U&E improves digestion and nutrient absorption in weaned piglets, exerts beneficial effects on intestinal morphology and microflora, and enhances the immune and antioxidant capabilities in mode of weaned piglets. Thus, SMWP-U&E exhibits potential as a new type of plant-derived additive and novel prebiotics.

Hydrothermal fabrication of sandwich-structured Silver sulfide/ferroferric oxide/silver metavanadate graphene microtube using capillary effect for enhancing photocatalytic degradation and disinfection.

As photocatalyst the low recombination efficiency and efficient utilization of photoelectron-holes are crucial for high photodegradation efficiencies, rapid disinfection in water catalytic purification. Herein, a sandwich-structured Z-scheme Silver sulfide/ferroferric oxide/silver metavanadate graphene microtube composite photocatalyst (Ag2S/Fe3O4/AgVO3@GM) was successfully prepared by a novel strategy using capillary effect combined with hydrothermal method. In this sandwich-structured composite, Ag2S, Fe3O4 and AgVO3 are anchored in the inner, middle and outer layers of graphene microtube, respectively, which construct a Z-scheme system with spatially separated microtopography. The Fe3O4 nanoparticles (NPs) in the middle of graphene microtube layer not only help the composite photocatalyst recycle due to their superparamagnetism but also serve as the redox mediator in the Z-scheme system to collect and consume the electrons and holes from AgVO3 and Ag2S on inner/outer layer graphene microtube, which can effectively facilitate the separation rate of photo-generated charge carriers, and generate more activity radicals. Moreover, the spatially separated graphene microtube micromorphology can significantly promote the mass transport efficiency in photocatalytic reaction. The obtained Ag2S/Fe3O4/AgVO3@GM shows remarkable performance for photocatalytic degradation (towards methyl orange (MO) about 98% within 30 min) and disinfection (100% Escherichia coli (E. coli) inactivation) and high cyclic stability.

Enhancement of Solasodine Extracted from Fruits of Solanum nigrum L. by Microwave-Assisted Aqueous Two-Phase Extraction and Analysis by High-Performance Liquid Chromatography.

Background: Solasodine is a major bioactive ingredient in Solanum nigrum L. that has strong pharmacological characteristics. Therefore, the development of a simple and effective extraction method for obtaining solasodine is highly important. This study aims to provide a rapid and effective method for extracting solasodine from Solanum nigrum L. by microwave-assisted aqueous two-phase extraction (MAATPE). Methods: First, the high-performance liquid chromatography (HPLC) conditions were established for the detection of solasodine. Then, the aqueous two-phase system (ATPS) compositions were examined. On the basis of the results of single-factor experiments, for a better yield, response surface methodology (RSM) was used to optimize influential factors including the extraction temperature, extraction time and liquid-to-solid ratio. Results: The maximum extraction yield of 7.11 ± 0.08 mg/g was obtained at 44 °C, an extraction time of 15 min, and a liquid-to-solid ratio of 42:1 mL/g in the ATPS consisting of EtOH solvent, (NH4)2SO4, and water (28:16:56, w/w/w). The extraction yield of the alkaloid obtained using this method was markedly higher than those of microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE). Conclusions: In this work, solasodine was extracted by MAATPE for the first time and a high yield was obtained. MAATPE is a simple, rapid, and green technique for extraction from medical plants. Thus, the present study will enable the development of a feasible extraction method of active alkaloids from Solanum nigrum L.

Application of natural deep eutectic solvents to extract ferulic acid from Ligusticum chuanxiong Hort with microwave assistance.

In this study, a method using natural deep eutectic solvents (NADES) combined with microwave-assistance extraction (MAE) was researched for the first time to establish an environmentally-friendly method for extracting ferulic acid from Ligusticum chuanxiong Hort. 20 kinds of NADES were initially screened, then response surface methodology was performed to optimize the NADES-MAE extraction of ferulic acid in L. c on the basis of the results of single-factor experiments. The results demonstrated that NADES could provide better extraction yields of ferulic acid than conventional solvents, and the combination of choline chloride and 1,2-propanediol was the most effective. The optimal conditions were an extraction time of 20 min, an extraction temperature of 68 °C, and a solvent-to-solid ratio of 30 : 1 mL g-1. Under these conditions, the extraction yield of ferulic acid with NADES-MAE (2.32 mg g-1) was higher than that using traditional extraction methods. This research demonstrates that this approach, which adopts NADES as a green solvent and MAE as an assistant extraction technique, could be an excellent choice to design an environmentally-friendly method for extracting phenolic compounds in various materials.

Fabrication of a three-dimensional porous Z-scheme silver/silver bromide/graphitic carbon nitride@nitrogen-doped graphene aerogel with enhanced visible-light photocatalytic and antibacterial activities.

A novel three-dimensional (3D) porous Z-scheme silver/silver bromide/graphitic carbon nitride@nitrogen-doped graphene aerogel (Ag/AgBr/g-C3N4@NGA) photocatalyst was successfully fabricated by a facile hydrothermal and freeze-drying method, and its photocatalytic degradation performance and inactivation effects were also evaluated. The series of characterization results certified that the obtained Ag/AgBr/g-C3N4@NGA synergistically integrates the structural and functional advantages of the Ag/AgBr species and g-C3N4 into the 3D macroscopic porous nitrogen-doped graphene aerogel (NGA) with high conductivity. Benefiting from a unique composition and structure, the obtained Ag/AgBr/g-C3N4@NGA exhibited excellent photocatalytic degradation efficiency for methyl orange (MO), approximately 96% after 30 min of visible-light illumination, which was approximately 1.7 times higher than that of a graphitic carbon nitride@nitrogen-doped graphene aerogel (g-C3N4@NGA). Meanwhile, Ag/AgBr/g-C3N4@NGA possessed high photodegradation efficiency for bisphenol A (BPA), approximately 92% within 120 min. Based on the underlying premise of maintaining the original morphology, the mass loss of Ag/AgBr/g-C3N4@NGA is below 5%, and its excellent photocatalytic performance was also well maintained after eight cycles. Moreover, Ag/AgBr/g-C3N4@NGA has a disinfection effect on E. coli (approximately 6 log inactivation) and S. aureus (approximately 1.2 log inactivation) in 60 min of visible-light illumination, and an excellent disinfection effect on E. coli was maintained after five applications.

Processable enzyme-hybrid conductive polymer composites for electrochemical biosensing.

A new approach for the facile fabrication of electrochemical biosensors using a biohybrid conducting polymer was demonstrated using glucose oxidase (GOx) and poly (3, 4-ethylenedioxythiophene) (PEDOT) as a model. The biohybrid conducting polymer was prepared based on a template-assisted chemical polymerisation leading to the formation of PEDOT microspheres (PEDOT-MSs), followed by in-situ deposition of platinum nanoparticles (PtNPs) and electrostatic immobilisation of glucose oxidase (GOx) to form water processable GOx-PtNPs-PEDOT-MSs. The morphology, chemical composition and electrochemical performance of the GOx-PtNPs-PEDOT-MS-based glucose biosensor were characterised using scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Fourier transform infrared (FTIR) spectroscopy, zeta potential and electrochemical measurements, respectively. The biosensor delivered a linear response for glucose over the range 0.1-10mM (R2 = 0.9855) with a sensitivity of 116.25µAmM-1cm-2, and limit of detection of 1.55µM (3×SD/sensitivity). The sensitivity of the developed PEDOT-MS based biosensor is significantly higher (2.7 times) than the best reported PEDOT-based glucose biosensor in the literature. The apparent Michaelis-Menten constant (Kmapp) of the GOx-PtNPs-PEDOT-MS-based biosensors was calculated as 7.3mM. Moreover, the biosensor exhibited good storage stability, retaining 97% of its sensitivity after 12 days storage. This new bio-hybrid conducting polymer combines the advantages of micro-structured morphology, compatibility with large-scale manufacturing processes, and intrinsic biocatalytic activity and conductivity, thus demonstrating its potential as a convenient material for printed bioelectronics and sensors.

Facile synthesis of hydroxyapatite/yeast biomass composites and their adsorption behaviors for lead (II).

For the first time, the hydroxyapatite (HAp)/yeast biomass composites were successfully synthesized through a facile alkaline ultrasound cavitation method, and used as a novel sorbent for removal of Pb(2+) from aqueous solution. The obtained HAp/yeast biomass composites were characterized by various techniques, including SEM, EDX, XRD, TGA, FTIR, XPS and fluorescence detection, respectively. It was found that the yeast cells were wrapped by the well-dispersed HAp, and more functional groups (such as carboxyl, hydroxyl and amino) on yeast surface were exposed. Also, varying factors that may affect the adsorption efficiency of HAp/yeast biomass composites, such as solution pH, reaction temperature and time, have been carefully investigated respectively. Remarkably, more than 99% of Pb(2+) can be removed by the HAp/yeast biomass composites. Evidence from FTIR and XPS analysis revealed that the higher removal efficiency should be ascribed to the synergetic effect of synthesized HAp and more functional groups exposed on yeast surface.

Microemulsion formulation of Carbendazim and its in vitro antifungal activities evaluation.

The fungus Rhizoctonia solani Kuhn is a widespread and destructive plant pathogen with a very broad host range. Although various pathogens, including R. solani, have been traditionally controlled using chemical pesticides, their use faces drawbacks such as environmental pollution, development of pesticide resistance, and other negative effects. Carbendazim is a well-known antifungal agent capable of controlling a broad range of plant diseases, but its use is hampered by its poor aqueous solubility. In this study, we describe an environmentally friendly pharmaceutical microemulsion system using carbendazim as the active ingredient, chloroform and acetic acid as solvents, and the surfactants HSH and 0204 as emulsifiers. This system increased the solubility of carbendazim to 30 g/L. The optimal microemulsion formulation was determined based on a pseudo-ternary phase diagram; its physicochemical characteristics were also tested. The cloud point was greater than 90°C and it was resistant to freezing down to -18°C, both of which are improvements over the temperature range in which pure carbendazim can be used. This microemulsion meets the standard for pesticide microemulsions and demonstrated better activity against R. solani AG1-IA, relative to an aqueous solution of pure carbendazim (0.2 g/L). The mechanism of activity was reflected in the inhibition of against R. solani AG1-IA including mycelium growth, and sclerotia formation and germination were significantly better than that of 0.2 g/L carbendazim water solution according to the results of t-test done by SPSS 19.

Heterosis in early maize ear inflorescence development: a genome-wide transcription analysis for two maize inbred lines and their hybrid.

Heterosis, or hybrid vigor, contributes to superior agronomic performance of hybrids compared to their inbred parents. Despite its importance, little is known about the genetic and molecular basis of heterosis. Early maize ear inflorescences formation affects grain yield, and are thus an excellent model for molecular mechanisms involved in heterosis. To determine the parental contributions and their regulation during maize ear-development-genesis, we analyzed genome-wide digital gene expression profiles in two maize elite inbred lines (B73 and Mo17) and their F1 hybrid using deep sequencing technology. Our analysis revealed 17,128 genes expressed in these three genotypes and 22,789 genes expressed collectively in the present study. Approximately 38% of the genes were differentially expressed in early maize ear inflorescences from heterotic cross, including many transcription factor genes and some presence/absence variations (PAVs) genes, and exhibited multiple modes of gene action. These different genes showing differential expression patterns were mainly enriched in five cellular component categories (organelle, cell, cell part, organelle part and macromolecular complex), five molecular function categories (structural molecule activity, binding, transporter activity, nucleic acid binding transcription factor activity and catalytic activity), and eight biological process categories (cellular process, metabolic process, biological regulation, regulation of biological process, establishment of localization, cellular component organization or biogenesis, response to stimulus and localization). Additionally, a significant number of genes were expressed in only one inbred line or absent in both inbred lines. Comparison of the differences of modes of gene action between previous studies and the present study revealed only a small number of different genes had the same modes of gene action in both maize seedlings and ear inflorescences. This might be an indication that in different tissues or developmental stages, different global expression patterns prevail, which might nevertheless be related to heterosis. Our results support the hypotheses that multiple molecular mechanisms (dominance and overdominance modes) contribute to heterosis.

Whole-genome sequencing of cultivated and wild peppers provides insights into Capsicum domestication and specialization.

As an economic crop, pepper satisfies people's spicy taste and has medicinal uses worldwide. To gain a better understanding of Capsicum evolution, domestication, and specialization, we present here the genome sequence of the cultivated pepper Zunla-1 (C. annuum L.) and its wild progenitor Chiltepin (C. annuum var. glabriusculum). We estimate that the pepper genome expanded ∼0.3 Mya (with respect to the genome of other Solanaceae) by a rapid amplification of retrotransposons elements, resulting in a genome comprised of ∼81% repetitive sequences. Approximately 79% of 3.48-Gb scaffolds containing 34,476 protein-coding genes were anchored to chromosomes by a high-density genetic map. Comparison of cultivated and wild pepper genomes with 20 resequencing accessions revealed molecular footprints of artificial selection, providing us with a list of candidate domestication genes. We also found that dosage compensation effect of tandem duplication genes probably contributed to the pungent diversification in pepper. The Capsicum reference genome provides crucial information for the study of not only the evolution of the pepper genome but also, the Solanaceae family, and it will facilitate the establishment of more effective pepper breeding programs.

Genome expression profile analysis of the maize sheath in response to inoculation to R. solani.

Currently, the molecular regulation mechanisms of disease-resistant involved in maize leaf sheaths infected by banded leaf and sheath blight (BLSB) are poorly known. To gain insight into the transcriptome dynamics that are associated with their disease-resistant, genome-wide gene expression profiling was conducted by Solexa sequencing. More than four million tags were generated from sheath tissues without any leaf or development leaf, including 193,222 and 204,824 clean tags in the two libraries, respectively. Of these, 82,864 (55.4 %) and 91,678 (51.5 %) tags were matched to the reference genes. The most differentially expressed tags with log2 ratio >2 or <-2 (P < 0.001) were further analyzed, representing 1,476 up-regulated and 1,754 down-regulated genes, except for unknown transcripts, which were classified into 11 functional categories. The most enriched categories were those of metabolism, signal transduction and cellular transport. Next, the expression patterns of 12 genes were assessed by quantitative real-time PCR, and it is showed the results were general agreement with the Solexa analysis, although the degree of change was lower in amplitude. In conclusion, we first reveal the complex changes in the transcriptome during the early development of maize sheath infected by BLSB and provide a comprehensive set of data that are essential for understanding its molecular regulation mechanism.

Combined small RNA and degradome sequencing reveals microRNA regulation during immature maize embryo dedifferentiation.

Genetic transformation of maize is highly dependent on the development of embryonic calli from the dedifferentiated immature embryo. To better understand the regulatory mechanism of immature embryo dedifferentiation, we generated four small RNA and degradome libraries from samples representing the major stages of dedifferentiation. More than 186 million raw reads of small RNA and degradome sequence data were generated. We detected 102 known miRNAs belonging to 23 miRNA families. In total, we identified 51, 70 and 63 differentially expressed miRNAs (DEMs) in the stage I, II, III samples, respectively, compared to the control. However, only 6 miRNAs were continually up-regulated by more than fivefold throughout the process of dedifferentiation. A total of 87 genes were identified as the targets of 21 DEM families. This group of targets was enriched in members of four significant pathways including plant hormone signal transduction, antigen processing and presentation, ECM-receptor interaction, and alpha-linolenic acid metabolism. The hormone signal transduction pathway appeared to be particularly significant, involving 21 of the targets. While the targets of the most significant DEMs have been proved to play essential roles in cell dedifferentiation. Our results provide important information regarding the regulatory networks that control immature embryo dedifferentiation in maize.

Preparation and characterization of EDTAD-modified magnetic-Fe3O4 chitosan composite: application of comparative adsorption of dye wastewater with magnetic chitosan.

Ethylenediaminetetraacetic dianhydride (EDTAD)-modified magnetic-Fe3O4 chitosan (EMC), prepared using the cross-link agent glutaraldehyde and chemicals Fe3O4, chitosan, and EDTAD, was used to compare the adsorption of methylene blue (MB) with magnetic chitosan (MC). The composite structure was confirmed by multiple characterization techniques, including scanning electron microscopy (SEM), X-ray powder diffraction, Fourier transform infrared spectroscopy (FTIR), and potentiometric titration methods. The characterization results suggest that Fe3O4 particles successfully bound on the surface of chitosan, and the EDTAD thoroughly modified the MC. Furthermore, EMC had more amino, carboxyl, and hydroxy groups than typical MC. Adsorption conditions, such as pH values, initial concentrations of MB, reaction temperature, and contact time were systematically examined. In comparison, the maximum adsorption capacity of EMC was approximately twice as much as that of MC. The recovery efficiency for EMC was >80% using 0.1 M HCl as an eluent solution. Therefore, the results reported herein indicate that EMC is very attractive and imply a practical application for dye wastewater treatment.

Facile preparation of high-quality Pt/reduced graphene oxide nanoscrolls for methanol oxidation.

A simple and novel approach for the preparation of a Pt/reduced graphene oxide nanoscroll (Pt/RGOS) nanocatalyst is reported for the first time. The Pt/reduced graphene oxide (Pt/RGO) was fabricated by the co-reduction of GO and Pt salt using ethylene glycol under microwave irradiation, then the Pt/RGOSs were obtained by oxygen implosion in situ rolling up of the Pt/RGO using catalytic decomposition of Pt towards H2O2 under ultrasonication. Transmission electron microscopy shows that the Pt nanoparticles are uniformly dispersed on the reduced graphene oxide nanoscrolls with tubular structure, open edges and ends, and tubular diameter ranging from 10 to 100 nm. X-ray diffraction indicates that the crystal structure and diffraction intensity of the platinum practically remains unchanged, and the RGO has not been oxidized before or after rolling. Raman spectroscopy reveals that the Pt/RGOSs have a higher D/G ratio (1.2) than Pt/RGO (1.1). BET (Brunauer, Emmett and Teller) results exhibit that the Pt/RGOSs possess higher specific surface area and broader pore size range (188 m(2) g(-1), 25-45 nm) than Pt/RGO (122 m(2) g(-1), 30-38 nm). Additionally, the electrocatalytic performance of the Pt/RGOSs for methanol oxidation was evaluated, and the results show that the Pt/RGOSs possess significantly higher electrocatalytic activity and stability than Pt/RGO.

Transcriptional responses of maize seedling root to phosphorus starvation.

Maize (Zea mays) is the most widely cultivated crop around the world, however, it is commonly affected by phosphate (Pi) deficiency and the underlying molecular basis of responses mechanism is still unknown. In this study, the transcriptional response of maize roots to Pi starvation at 3 days after the onset of Pi deprivation was assessed. The investigation revealed a total of 283 Pi-responsive genes, of which 199 and 84 genes were found to be either up- or down-regulated respectively, by 2-fold or more. Pi-responsive genes were found to be involved in sugar and nitrogen metabolic pathways, ion transport, signal transduction, transcriptional regulation, and other processes related to growth and development. In addition, the expression patterns of maize inorganic phosphorus transporters, acid phosphatase, phytase, 2-deoxymugineic acid synthase1, POD and MYB transcription factor were validated in 178 roots response to low phosphorus stress. of which, two genes encoding phytase and acid phosphatase were significantly induced by Pi deficiency and may play a pivotal role in the process of absorption and re-utilization of Pi in Maize. These results not only enhance our knowledge about molecular processes associated with Pi deficiency, but also facilitate the identification of key molecular determinants for improving Pi use in maize. Moreover, this work sets a framework to produce Pi-specific maize microarrays to study the changes in global gene expression between Pi-efficient and Pi-inefficient maize genotypes.

Genome expression profile analysis reveals important transcripts in maize roots responding to the stress of heavy metal Pb.

Lead (Pb) has become one of the most abundant heavy metal pollutants of the environment. With its large biomass, maize could be an important object for studying the phytoremediation of Pb-contaminated soil. In our previous research, we screened 19 inbred lines of maize for Pb concentration, and line 178 was identified to be a hyperaccumulator for Pb in both the roots and aboveground parts. To identify important genes and metabolic pathways related to Pb accumulation and tolerance, line 178 was underwent genome expression profile under Pb stress and a control (CK). A total of approximately 11 million cDNA tags were sequenced and 4 665 539 and 4 936 038 clean tags were obtained from the libraries of the test and CK, respectively. In comparison to CK, 2379 and 1832 genes were identified up- or downregulated, respectively, more than fivefolds under Pb stress. Interestingly, all the genes were related to cellular processes and signaling, information storage and processing or metabolism functions. Particularly, the genes involved in posttranslational modification, protein turnover and chaperones; signal transduction, carbohydrate transport and metabolism; and lipid transport and metabolism significantly changed under the treatment. In addition, seven pathways including ribosome, photosynthesis, and carbon fixation were affected significantly, with 118, 12, 34, 21, 18, 72 and 43 differentially expressed genes involved. The significant upregulation of the ribosome pathway may reveal an important secret for Pb tolerance of line 178. And the sharp increase of laccase transcripts and metal ion transporters were suggested to account in part for Pb hyperaccumulation in the line.