RESUMO
To establish a production platform for recombinant proteins in rice suspension cells, we first constructed a Gateway-compatible binary T-DNA destination vector. It provided a reliable and effective method for the rapid directional cloning of target genes into plant cells through Agrobacterium-mediated transformation. We used the approach to produce mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) in a rice suspension cell system. The promoter for the αAmy3 amylase gene, which is induced strongly by sugar depletion, drove the expression of mGM-CSF. The resulting recombinant protein was fused with the αAmy3 signal peptide and was secreted into the culture medium. The production of rice-derived mGM-CSF (rmGM-CSF) was scaled up successfully in a 2-L bioreactor, in which the highest yield of rmGM-CSF was 24.6 mg/L. Due to post-translational glycosylation, the molecular weight of rmGM-CSF was larger than that of recombinant mGM-CSF produced in Escherichia coli. The rmGM-CSF was bioactive and could stimulate the proliferation of a murine myeloblastic leukemia cell line, NSF-60.
Assuntos
Reatores Biológicos , Biotecnologia/métodos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Oryza/metabolismo , Plantas Geneticamente Modificadas , Agrobacterium/genética , Animais , Técnicas de Cultura de Células , Meios de Cultura/química , DNA Bacteriano , Escherichia coli/genética , Vetores Genéticos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/química , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Camundongos , Peso Molecular , Oryza/genética , Regiões Promotoras Genéticas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
An ultralow program/erase voltage ( |VP/E| = 4 V) is demonstrated by using an antiferroelectric-ferroelectric field-effect transistor (AFE-FE-FET) through a multipeak coercive E -field ( EC ) concept for a four-level stable state with outstanding endurance (>105 cycles) and data retention (>104 s at 65 °C). The mixture of ferroelectric (FE) and AFE domains can provide stable multistate and data storage with zero bias for multilevel cell (MLC) applications. HfZrO2 (HZO) with AFE-FE assembles an orthorhombic/tetragonal (o/t) phase composition and is achieved by [Zr] modulation in an HZO system. MLC characteristics not only improve high-density nonvolatile memory (NVM) but are also beneficial to neuromorphic device applications.
Assuntos
EletricidadeRESUMO
Ferroelectric (FE) Hf1-xZrxO2 is a potential candidate for emerging memory in artificial intelligence (AI) and neuromorphic computation due to its non-volatility for data storage with natural bi-stable characteristics. This study experimentally characterizes and demonstrates the FE and antiferroelectric (AFE) material properties, which are modulated from doped Zr incorporated in the HfO2-system, with a diode-junction current for memory operations. Unipolar operations on one of the two hysteretic polarization branch loops of the mixed FE and AFE material give a low program voltage of 3 V with an ON/OFF ratio >100. This also benefits the switching endurance, which reaches >109 cycles. A model based on the polarization switching and tunneling mechanisms is revealed in the (A)FE diode to explain the bipolar and unipolar sweeps. In addition, the proposed FE-AFE diode with Hf1-xZrxO2 has a superior cycling endurance and lower stimulation voltage compared to perovskite FE-diodes due to its scaling capability for resistive FE memory devices.