Multi-stage voltage droop compensation based on resonant circuit for unipolar solid-state Marx Generators.

The low-voltage droop of high-voltage pulses is required to provide stable pulsed electric fields in many applications. Increasing the capacitance of energy storage capacitors increases both the size and the cost of the system. In this paper, four compensation stages based on the resonant circuit have been inserted into a 16-stage solid-state Marx generator to compensate for the voltage droop in different conditions. The nearly linear part of the sinusoidal voltage is precisely added to the load during discharging as compensation, and the rectangular pulsed voltage with little droop can be realized. Different numbers of compensation stages and different resonant inductances can compensate the droop to different levels, which means the compensation effect is also adjustable. Moreover, these compensation stages can operate as common stages in Marx generators as long as we open-circuit the resonant circuits. Since the capacitors in resonant compensation stages are also charged in parallel with capacitors in common stages, no auxiliary power supply is required. Simulating and experimental results show that the droop of a 9 kV pulse can be ideally compensated over a 500 Ω resistive load at various pulse widths. The pulse width should be shorter than the length of the nearly linear part of the sinusoidal voltage.

Proteomic analysis of saffron (Crocus sativus L. ) grown under conditions of cadmium toxicity / Análise proteômica do açafrão (Crocus sativus L. ) cultivado sob condições de toxicidade por cádmio

Cd is a highly detrimental global environmental pollutant. Plants have evolved complex defense mechanisms as an adaptation to against Cd toxicity. In this study, a pot experiment was performed to evaluate the protein profile of saffron in response to Cd stress. Fifteen proteins were found to be up-regulated in the leaves of plants under Cd stress and were primarily related to metabolism, signal transduction, stress and defense response and energy. Eleven proteins were found to be down-regulated following Cd treatment, including ribulose bisphosphate carboxylase/oxygenase (Rubisco), ferredoxin-NADP reductase, a 70 kDa heat shock-related protein and three protein synthesis-associated proteins. The results provide valuable insights regarding the molecular mechanism of saffron in response to Cd toxicity and the possible utilization of genetic resources in developing Cd tolerant/low-accumulation saffron.

O cádmio (Cd) é um poluente ambiental global altamente prejudicial. As plantas desenvolveram mecanismos de defesa complexos como uma adaptação contra a toxicidade por Cd. Neste estudo, realizou-se um experimento em vaso para avaliar o perfil proteico do açafrão em resposta ao estresse por Cd. Foi descoberto que quinze proteínas foram supra-reguladas (up-regulated) nas folhas de plantas sob estresse por Cd e foram principalmente relacionados ao metabolismo, transdução de sinal, estresse e resposta de defesa e energia. Foi descoberto ainda que onze proteínas foram infra-reguladas (down-regulated) após tratamento com Cd, incluindo ribulose bifosfato carboxilase oxigenase (RuBisCO), ferredoxina-NADP redutase, uma proteína relacionada com o choque térmico de 70 kDa e três proteínas associadas à síntese de proteínas. Os resultados fornecem informações valiosas sobre o mecanismo molecular do açafrão em resposta à toxicidade do Cd e a possível utilização de recursos genéticos no desenvolvimento de açafrão tolerante ao Cd e de baixa acumulação.

Unveiling of Dominant Fungal Pathogens Associated With Rusty Root Rot of Panax notoginseng Based on Multiple Methods.

Root rot is an important disease hampering the sustainable cultivation of Panax notoginseng. Culture-dependent and independent techniques were used to elucidate the dominant fungal pathogen of rusty root rot of P. notoginseng. Based on Illumina sequencing profiles for fungi using ITS primers, five phyla-namely Ascomycota, Basidiomycota, Glomeromycota, Zygomycota, and Chytridiomycota-were identified, and the analyses showed that the Ascomycota was the dominant phylum (∼50 to 97%), especially in the symptomatic samples. Out of 226 total genera identified, seven genera had over 1% average abundance, including Ilyonectria, Fusarium, Tetracladium, Cladosporium, Rhizophagus, Alternaria, and Perisporiopsis. However, only Ilyonectria was the predominant genera in the symptomatic samples (∼76 to 80%), while the others, including Fusarium, had higher abundances in asymptomatic samples. Based on in vitro and in vivo pathogenicity, the isolate G3B was demonstrated to be the pathogen causing rusty root rot of P. notoginseng, and it was identified as Ilyonectria mors-panacis. Based on primers F2-R2 targeting the His3 gene of Ilyonectria, real-time quantitative PCR (qPCR) was performed as an additional proof confirming that I. mors-panacis was the dominant pathogen in the symptomatic samples during the years of the study (2014-2015).