A handheld continuous-flow real-time fluorescence qPCR system with a PVC microreactor.

The polymerase chain reaction (PCR) has unique advantages of sensitivity, specificity and rapidity in pathogen detection, which makes it at the forefront of academia and application in molecular biology diagnosis. In this study, we proposed a hand-held real-time fluorescence qPCR system, which can be used for the quantitative analysis of nucleic acid molecules. For the first time, we use a PVC microreactor which improved the transmittance of the microreactor and made it easy to collect the fluorescence signal. In order to make it portable, the system adopted a passive syringe for sample injection and integrated temperature control and detection with a lithium battery for power supply. What's more, the fluorescence signal was captured by using a smartphone through an external automatic robotic arm. This real-time qPCR system can detect genomic DNA of the H7N9 avian influenza over four orders of magnitude of concentration from 107 to 104 copies per µL. In addition, it was verified that the fluorescence images obtained by this system were clearer than those obtained by a traditional system (using a PTFE spatial PCR microreactor) with two typical dyes and a probe tested-EvaGreen, SYBR Green and FAM.

Engineering multiscale polypyrrole/carbon nanotubes interface to boost electron utilization in a bioelectrochemical system coupled with chemical absorption for NO removal.

The chemical absorption-bioelectrochemical reduction (CABER) integrated system provides an alternative of good potential for NO removal. The efficient utilization of cathode electrons directly determines the system performance and operating cost. Herein, we synthesize a polypyrrole/carbon nanotubes (PPy/CNTs) composite to engineer a micro-and nanoscale interface with low resistance and high biocompatibility between the cathode and biofilms in the CABER system. The resulting PPy/CNTs biocathodes exhibit 36.4% increase in biomass density, 40.7%-302.6% increase in Faraday efficiency along Fe(III)EDTA reduction, and 204% increase in Fe(II)EDTA-NO reduction rate. The enrichment of functional microorganisms is validated to be a key strengthening factor, as the proportion of which increased from 57.9% to 84.6%. Moreover, for efficient electron transfer and utilization, a low-resistance electron transfer route, "electrode substrate → PPy (→ CNTs) → microbial cells → Fe(III)EDTA or Fe(II)EDTA-NO", is realized in the multiscale conductive networks constructed of PPy/CNTs composite and microbial nanowires.

Mass transfer and reaction simultaneously enhanced airlift microbial electrolytic cell system with high gaseous o-xylene removal capacity.

To overcome the limitation of mass transfer and reaction rate involved in the biodegradation of gaseous o-xylene, the airlift reactor and microbial electrolysis cell were integrated to construct an airlift microbial electrolysis cell (AL-MEC) system for the first time, in which the bioanode was modified by polypyrrole to further improve biofilm attachment. The developed AL-MEC system achieved 95.4% o-xylene removal efficiency at optimized conditions, and maintained around 75% removal efficiency even while the inlet o-xylene load was as high as 684 g m-3 h-1. The existence of O2 exhibited a competition in electrons with the bioanode but a positive effect on ring-opening process in the o-xylene oxidation. The limitation of mass transfer had been overcome as the empty bed resistance time in the range of 20-80 s did not influence the system performance significantly. The microbial community analysis confirmed the o-xylene degradation microbes and electroactive bacteria were the dominant, which could be further enriched at 0.3 V against standard hydrogen electrode. This work revealed the feasibility of the AL-MEC system for the degradation of o-xylene and similar compounds, and provided insights into bioelectrochemical system design with high gaseous pollution removal capacity.

Genome-wide identification and analysis of the Q-type C2H2 gene family in potato (Solanum tuberosum L.).

Plant Q-type C2H2 zinc finger proteins play an important role in plant tolerance to abiotic stresses. Although the Q-type C2H2 gene family has been identified in many plants, little is known about it in potato (Solanum tuberosum). In the present study, a total of 79 Q-type C2H2 proteins in potato (StZFPs) were identified and their distribution on chromosomes, gene structure, and conserved motifs was assessed. According to their protein structural and phylogenetic features, these 79 StZFPs were classified into 12 distinct subclasses. Collinearity analysis showed that tandem and segmental duplication events played a crucial role in expansion of the StZFP gene family. Synteny analysis indicated that 11 and 21 StZFP genes were orthologous to Arabidopsis and wheat (Triticum aestivum), respectively. RNA-seq data were used to analyze the tissue-specific expression and abiotic stress responses of the StZFP genes. Furthermore, we analyzed the expression of StZFP genes in drought-sensitive and drought-tolerant potato cultivars under drought stress. Subsequently, we used qPCR (Quantitative real-time-PCR) to calculate the relative expression of candidate genes in potato plantlets treated with NaCl (100 mM) and PEG 6000 (10% w/v) for 24 h. Such candidate genes could provide valuable information for abiotic stress resistance research in potato.