Perpendicular magnetization and exchange bias in epitaxial NiO/[Ni/Pt]_(2)multilayers

The realization of perpendicular magnetization and perpendicular exchange bias(PEB)in magnetic multilayers is important for the spintronic applications.NiO(t)/[Ni(4 nm)/Pt(1 nm)]_(2)multilayers with varying the NiO layer thickness t have been epitaxially deposited on SrTiO;(001)substrates.Perpendicular magnetization can be achieved when t<25 nm.Perpendicular magnetization originates from strong perpendicular magnetic anisotropy(PMA),mainly resulting from interfacial strain induced by the lattice mismatch between the Ni and Pt layers.The PMA energy constant decreases monotonically with increasing t,due to the weakening of Ni(001)orientation and a little degradation of the Ni–Pt interface.Furthermore,significant PEB can be observed though NiO layer has spin compensated(001)crystalline plane.The PEB field increases monotonically with increasing t,which is considered to result from the thickness dependent anisotropy of the NiO layer.

Epigenetic therapies in acute myeloid leukemia: the role of hypomethylating agents, histone deacetylase inhibitors and the combination of hypomethylating agents with histone deacetylase inhibitors

Epigenetic regulation includes changes of DNA methylation and modifications of histone proteins and is essential for normal physiologic functions,especially for controlling gene expression.Epigenetic dysregulation plays a key role in disease pathogenesis and progression of some malignancies,including acute myeloid leukemia(AML).Epigenetic therapies,including hypomethylating agents(HMAs)and histone deacetylase(HDAC)inhibitors,were developed to reprogram the epigenetic abnormalities in AML.However,the molecular mechanisms and therapeutic effects of the two agents alone or their combination remain unknown.An overview of these epigenetic therapies is given here.A literature search was conducted through PubMed database,looking for important biological or clinical studies related to the epigenetic regimens in the treatment of AML until October 15th,2019.Various types of articles,including original research and reviews,were assessed,identified,and eventually summarized as a collection of data pertaining the mechanisms and clinical effects of HMAs and HDAC inhibitors in AML patients.We provided here an overview of the current understanding of the mechanisms and clinical therapeutic effects involved in the treatment with HMAs and HDAC inhibitors alone,the combination of epigenetic therapies with intensive chemotherapy,and the combination of both types of epigenetic therapies.Relevant clinical trials were also discussed.Generally speaking,the large number of studies and their varied outcomes demonstrate that effects of epigenetic therapies are heterogeneous,and that HMAs combination regimens probably contribute to significant response rates.However,more research is needed to explore therapeutic effects of HDAC inhibitors and various combinations of HMAs and HDAC inhibitors.

Ecdysone receptor isoforms play distinct roles in larval–pupal–adult transition in Leptinotarsa decemlineata

A heterodimer of two nuclear receptors,ecdysone receptor(EcR)and ultraspiracle,mediates 20‐hydroxyecdysone(20E)signaling to modulate many aspects in insect life,such as molting and metamorphosis,reproduction,diapause and innate immunity.In the present paper,we intended to determine the isoform‐specific roles of EcR during larval–pupal–adult transition in the Colorado potato beetle.Double‐stranded RNAs(dsRNAs)were prepared using the common(dsEcR)or isoform‐specific(dsEcRA,dsEcRB1)regions of EcR as templates.Ingestion of either dsEcR or dsEcRA,rather than dsEcRB1,by the penultimate(3rd)and final(4th)instar larvae caused failure of larval–pupal and pupal–adult ecdysis.The RNA interference(RNAi)larvae remained as prepupae,or became deformed pupae and adults.Determination of messenger RNA(mRNA)levels of EcR isoforms found that LdEcRA regulates the expression of LdEcRB1.Moreover,silencing the two EcR transcripts,LdEcRA or LdEcRB1 reduced the mRNA levels of Ldspo and Ldsad,and lowered 20E titer.In contrast,the expression levels of HR3,HR4,E74 and E75 were significantly decreased in the LdEcR or LdEcRA RNAi larvae,but not in LdEcRB1 depleted specimens.Dietary supplement with 20E did not restore the expression of five 20E signaling genes(USP,HR3,HR4,E74 and E75),and only partially alleviated the pupation defects in dsEcR‐or dsEcRA‐fed beetles.These data suggest that EcR plays isoform‐specific roles in the regulation of ecdysteroidogenesis and the transduction of 20E signal in L.decemlineata.