Co-Detoxification of Transformer Oil-Contained PCBs and Heavy Metals in Medical Waste Incinerator Fly Ash under Sub- and Supercritical Water

The simultaneous detoxification processes of transformer oil-contained PCBs and heavy metals in medical waste incinerator (MWI) fly ash were developed under sub- and supercritical water. The addition of MWI fly ash to transformer oil-contained PCBs was found to increase the destruction efficiency of PCBs, at the same time, it facilitated reducing the leaching concentration of toxic metals from residues (obtained after reaction) for harmless disposal. In this study, we elucidated primarily the catalysis possibility of heavy metals in raw MWI fly ash for PCBs degradation by adopting the sequential extraction procedure. For both MWI fly ashes, more than 90% destruction efficiency of PCBs was achieved at ≥375 °C for 30 min, and trichlorobenzene (TCB) existing in the transformer oil was also completely decomposed. The correlation of catalytic performance to PCBs degradation was discussed based on structural characteristics and dechlorinated products. Likewise, such process rendered residues innocuous through supercritical water treatment for reuse or disposal in landfill

Label-Free and Ultrasensitive Electrochemical Detection of Nucleic Acids Based on Autocatalytic and Exonuclease III-Assisted Target Recycling Strategy

In this work, a very simple, label-free, isothermal, and ultrasensitive electrochemical DNA biosensor has been developed on the basis of an autocatalytic and exonuclease III (Exo III)-assisted target recycling amplification strategy. A duplex DNA probe constructed by the hybridization of a quadruplex-forming oligomer with a molecular beacon is ingeniously designed and assembled on the electrode as recognition element. Upon sensing of the analyte nucleic acid, the strand of molecular beacon in the duplex DNA probe could be stepwise removed by Exo III accompanied by the releasing of target DNA and autonomous generation of new secondary target DNA fragment for the successive hybridization and cleavage process. Simultaneously, numerous quadruplex-forming oligomers are liberated and folded into G-quadruplex–hemin complexes with the help of K⁺ and hemin on the electrode surface to give a remarkable electrochemical response. Because of this autocatalytic target recycling amplification and the specifically catalyzed formation of G-quadruplex–hemin complexes, this newly designed protocol provides an ultrasensitive electrochemical detection of DNA down to the 10 fM level, can discriminate mismatched DNA from perfectly matched target DNA, and holds a great potential for early diagnosis in gene-related diseases. It further could be developed as a universal protocol for the detection of various DNA sequences and may be extended for the detection of aptamer-binding molecules

Light-Emission Enhancement in a Flexible and Size-Controllable ZnO Nanowire/Organic Light-Emitting Diode Array by the Piezotronic Effect

Enhancing the light emission of LED arrays by the piezotronic effect of ZnO NWs has recently attracted wide attention for the visual mapping of pressure. Here, to overcome deficiencies of ZnO LEDs, such as uncontrollable emission and poor emission efficiency, we designed a flexible, patterned ZnO/organic light-emitting device by combining the advantages of organic light-emitting materials and the piezoelectric effect of ZnO nanowires (NWs). The spatial resolution of the device can be tuned by the pattern size of the ZnO NW array. In addition, the light-emission character is solely determined by the organic light-emitting layer. The light-emission performance of the organic device is enhanced by the piezotronic transistors of the ZnO NW array through the modification of the energy band and reducing the Schottky barrier at the interface of the electrode and the semiconductor. By combining the advantages of the organic material and the piezotronic effect of ZnO NWs, this device shows potential for many applications, such as mechanosensation electronics

Electrophoresis of PCR amplified products of the candidate <i>cry1Ac</i> transgenic sugarcane plants.

<p>M, DNA Marker; 1–9, Basta-resistant plants; 10, Positive control (plasmid pGcry1Ac0229); 11, Negative control (non-transgenic sugarcane without bombardment); 12, Blank control.</p

Transgenic Sugarcane with a <i>cry1Ac</i> Gene Exhibited Better Phenotypic Traits and Enhanced Resistance against Sugarcane Borer

<div><p>We developed sugarcane plants with improved resistance to the sugarcane borer, <i>Diatraea saccharalis</i> (F). An expression vector pGcry1Ac0229, harboring the <i>cry1Ac</i> gene and the selectable marker gene, <i>bar</i>, was constructed. This construct was introduced into the sugarcane cultivar FN15 by particle bombardment. Transformed plantlets were identified after selection with Phosphinothricin (PPT) and Basta. Plantlets were then screened by PCR based on the presence of <i>cry1Ac</i> and 14 <i>cry1Ac</i> positive plantlets were identified. Real-time quantitative PCR (RT-qPCR) revealed that the copy number of <i>cry1Ac</i> gene in the transgenic lines varied from 1 to 148. ELISA analysis showed that Cry1Ac protein levels in 7 transgenic lines ranged from 0.85 μg/FWg to 70.92 μg/FWg in leaves and 0.04 μg/FWg to 7.22 μg/FWg in stems, and negatively correlated to the rate of insect damage that ranged from 36.67% to 13.33%, respectively. Agronomic traits of six transgenic sugarcane lines with medium copy numbers were similar to the non-transgenic parental line. However, phenotype was poor in lines with high or low copy numbers. Compared to the non-transgenic control plants, all transgenic lines with medium copy numbers had relatively equal or lower sucrose yield and significantly improved sugarcane borer resistance, which lowered susceptibility to damage by insects. This suggests that the transgenic sugarcane lines harboring medium copy numbers of the <i>cry1Ac</i> gene may have significantly higher resistance to sugarcane borer but the sugarcane yield in these lines is similar to the non-transgenic control thus making them superior to the control lines.</p></div

Cry1Ac protein expression in the leaves and stems of 14 different transgenic sugarcane lines detected by ELISA.

<p>Cry1Ac protein expression in the leaves and stems of 14 different transgenic sugarcane lines detected by ELISA.</p

Bioassay in the seedling stage.

<p><b>A</b>: Symptoms of non-transgenic sugarcane plantlets challenged with sugarcane borers; <b>B</b>: Symptoms of transgenic sugarcane plantlets challenged with sugarcane borers; <b>C</b>: Sugarcane borer feeding with non-transgenic sugarcane plantlets; <b>D</b>: Sugarcane borer feeding with transgenic sugarcane plantlets.</p

Damage comparison between transgenic and non-transgenic sugarcane stalks.

<p>Damage comparison between transgenic and non-transgenic sugarcane stalks.</p

Agronomic characteristics, industrial traits and the stalks borer damage percentage in transgenic sugarcane lines and the non-transgenic control.

<p>Agronomic characteristics, industrial traits and the stalks borer damage percentage in transgenic sugarcane lines and the non-transgenic control.</p

The accession numbers of protein and nucleotide acid of swine H3N2 influenza viruses.

<p>The accession numbers of protein and nucleotide acid of swine H3N2 influenza viruses.</p