Exfoliation of two-dimensional phosphorene sheets with enhanced photocatalytic activity under simulated sunlight

Two-dimensional phosphorene (2D-BP) nanosheets were successfully prepared by an environmental friendly water exfoliation process. The morphology and structure of exfoliated 2D-BP nanosheets were characterized by SEM, AFM, Raman and UV–Vis. The photocatalytic results demonstrated that 2D-BP nanasheets can generate reactive oxygen species of 1O2 and O2− and effectively enhance the photodegradation of dibutyl phthalate pollutants when coexist with water, oxygen, and light

Dispersive solid-phase microextraction with graphene oxide based molecularly imprinted polymers for determining bis(2-ethylhexyl) phthalate in environmental water

A novel graphene oxide-molecularly imprinted polymers (GO-MIPs) was prepared and applied for selective extraction and preconcentration of bis(2-ethylhexyl) phthalate (DEHP) in environmental water samples by using the dispersive solid-phase microextraction (DSPME) method. The GO-MIPs was synthesized via precipitation polymerization using GO, DEHP, methacrylic acid, and ethylene dimethacrylate as supporting materials, template molecules, functional monomer, and cross-linker, respectively. The prepared GO-MIPs were characterized by scanning electron microscope and Fourier transform infrared spectroscopy. The GO-MIPs-DSPME conditions including type and volume of elution solvents, adsorbents amount, initial concentration of DEHP, pH and ionic strength of water samples were investigated. Under optimized conditions, the DEHP was selectively and effectively extracted in real water samples and enrichment factors of over 100-fold were achieved. Good linearity was obtained with correlation coefficients (R2) over 0.999 and the detection limit (S/N = 3) was 0.92 ng mL−1. The average recoveries of the spiked samples at three concentration levels of DEHP ranged from 82% to 92% with the relative standard deviations less than 6.7%. The results indicated that the proposed GO-MIPs-DSPME extraction protocol combined with HPLC-UV determination could be applied for selective and sensitive analysis of trace DEHP phthalate in environmental water samples

Does endophyte symbiosis resist allelopathic effects of an invasive plant in degraded grassland?

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Genome-Wide Analysis of Codon Usage Bias in Epichloë festucae

Analysis of codon usage data has both practical and theoretical applications in understanding the basics of molecular biology. Differences in codon usage patterns among genes reflect variations in local base compositional biases and the intensity of natural selection. Recently, there have been several reports related to codon usage in fungi, but little is known about codon usage bias in Epichloë endophytes. The present study aimed to assess codon usage patterns and biases in 4870 sequences from Epichloë festucae, which may be helpful in revealing the constraint factors such as mutation or selection pressure and improving the bioreactor on the cloning, expression, and characterization of some special genes. The GC content with 56.41% is higher than the AT content (43.59%) in E. festucae. The results of neutrality and effective number of codons plot analyses showed that both mutational bias and natural selection play roles in shaping codon usage in this species. We found that gene length is strongly correlated with codon usage and may contribute to the codon usage patterns observed in genes. Nucleotide composition and gene expression levels also shape codon usage bias in E. festucae. E. festucae exhibits codon usage bias based on the relative synonymous codon usage (RSCU) values of 61 sense codons, with 25 codons showing an RSCU larger than 1. In addition, we identified 27 optimal codons that end in a G or C

Identification of <i>Epichloë</i> endophytes associated with wild barley (<i>Hordeum brevisubulatum</i>) and characterisation of their alkaloid biosynthesis

<p><i>Epichloë</i> species are biotrophic symbionts of many cool-season grasses that can cause grazing animal toxicosis. We identified fungi from <i>Hordeum brevisubulatum</i> as <i>Epichloë bromicola</i> based on morphological characteristics and <i>tefA</i> and <i>actG</i> gene sequences. Three isolates were examined, they contained <i>perA</i> gene and 10 out of the 14 <i>EAS</i> cluster genes, previously identified in <i>Epichloë inebrians</i> E818. Five out of 11 <i>LTM</i>/<i>IDT</i> cluster genes previously identified in <i>Epichloë festucae</i> Fl1 were present, but no <i>idtG</i>, indicating an inability to produce even early intermediates in the lolitrem B pathway. Only one <i>lolC</i> gene out of 11 <i>LOL</i> cluster genes previously identified in <i>E. festucae</i> E2368 was present in the three isolates. Chemotype analyses revealed infected samples contained only peramine, and not ergine, ergonovine, ergovaline or lolitrem B. This study provides new information about the host range and phylogenetic definition of <i>E. bromicola</i> and reveal a novel endophyte–grass combination in China.</p

Human Immunodeficiency Virus Type 1 Tat Accelerates Kaposi Sarcoma-Associated Herpesvirus Kaposin A-Mediated Tumorigenesis of Transformed Fibroblasts In Vitro as well as in Nude and Immunocompetent Mice1

Kaposi sarcoma-associated herpesvirus (KSHV) is necessary but not sufficient to cause Kaposi sarcoma (KS). Coinfection with human immunodeficiency virus type 1 (HIV-1), in the absence of antiretroviral suppressive therapy, drastically increases the risk of KS. Previously, we identified that HIV-1 transactivative transcription protein (Tat) was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the potential of Tat to influence tumorigenesis induced by KSHV Kaposin A, a product of KSHV that was encoded by the open reading frame K12 (a KSHV-transforming gene). By using colony formation in soft agar, 3H-TdR incorporation, cell cycle, and microarray gene expression analyses, we demonstrated that Tat enhanced proliferation as well as mitogen-activated protein kinase, signal transducer and activator of transcription 3, and phosphatidylinositol 3-kinase/protein kinase B signaling induced by Kaposin A in NIH3T3 cells. Animal experiments further demonstrated that Tat accelerated tumorigenesis by Kaposin A in athymic nu/nu mice. Cells obtained from primary tumors of nude mice succeeded inducing tumors in immunocompetent mice. These data suggest that Tat can accelerate tumorigenesis induced by Kaposin A. Our data present the first line of evidence that Tat may participate in KS pathogenesis by collaborating with Kaposin A in acquired immunodeficiency syndrome (AIDS)-related KS (AIDS-KS) patients. Our data also suggest that the model for Kaposin and Tat-mediated oncogenesis will contribute to our understanding of the pathogenesis of AIDS-KS at the molecular level and may even be important in exploring a novel therapeutic method for AIDS-KS