Floating-gate memristor based on a MoS2/h-BN/AuNPs mixed-dimensional heterostructure.

Memristors have recently received substantial attention because of its promising and unique application scenes emerging in neuromorphic computing which can achieve gains in computation speed by mimicking the topology of brains in electronic circuits. Traditional memristors made of bulk MoO3 and HfO2, etc. suffer from low switching ratio, short durability and poor stability. In this work, a floating-gate memristor is developed based on a mixed-dimensional heterostructure which is comprised of two-dimensional (2D) molybdenum disulfide (MoS2) and 0-dimensional (0D) Au nanoparticles (AuNPs) separated by an insulating hexagonal boron nitride (h-BN) layer, hereafter, MoS2/h-BN/AuNPs. We find that under the modulation of back-gate voltages, the MoS2/h-BN/AuNPs device operates reliably between a high resistance state (HRS) and a low resistance state (LRS) and that it shows multiple stable LRS states, demonstrating high potential of our memristor in application of multibit storage. The modulation effect can be attributed to the electron quantum tunneling between the AuNPs charge-trapping layer and MoS2 channel. Our memristor exhibits excellent durability and stability: the HRS and LRS remain more than 104 s without obvious degradation and the on/off ratio retains > 104 after more than 3000 switching cycles. We also demonstrate frequency-dependent memory properties upon electrical and optical pulse stimuli.

Nanodiamonds conjugated upconversion nanoparticles for bio-imaging and drug delivery.

A multifunctional nanoplatform with simultaneous imaging and therapeutic capacities has been fabricated by covalently conjugating nanodiamonds (NDs) with upconversion NaYF4:Yb,Er nanoparticles (UCNPs). Green emission can be observed for the UCNP-NDs composites under 980 nm excitation, and in vitro imaging was carried out towards HeLa cells. The UCNP-NDs also shows good drug storage capability toward anticancer drug doxorubicin (Dox) and exhibits significant pH-dependent drug-release behavior. Dox-loaded UCNP-NDs shows higher therapy efficiency towards Hela cells than free Dox when the equivalent concentration of the Dox is more than 10 µg/mL. Thus, a favorable strategy may be provided to decrease the side effects of Dox, minimize drug dose, and improve its efficacy. These findings highlight the fascinating features of UCNP-NDs nanocomposites as upconversion fluorescence imaging contrast agents and doxorubicin loading carrier. In addition, this work may also provide a novel strategy for the design of multifunctional nanoplatforms.

Induction of systemic resistance against tobacco mosaic virus by Ningnanmycin in tobacco.

Ningnanmycin (NNM) is an antiviral agent firstly isolated from Strepcomces noursei var·xichangensisn. Studies have shown that NNM promotes PAL, POD and SOD activity and possesses antiviral activity against tobacco mosaic virus (TMV). In this study, our results demonstrated that NNM inhibited the polymerization process of TMV coat protein (TMV-CP) in vitro and promoted the systemic accumulation of pathogenesis-related proteins (PRs), which are the markers of systemic acquired resistance (SAR). An non-expressor, pathogenesis-related genes 1 (NPR1) that regulates SAR and induces systemic resistance (ISR), increased. In addition, the Jaz3 expression increase showed that NNM also induced ISR. Based on the results of this work and earlier reports, it is suggesting that NNM induces tobacco systemic resistance against TMV via activating multiple plant defense signaling pathways.

[Clinical research of HPV DNA detection and HPV RNA detection in single time].

OBJECTIVE: To research the application of the single time detection of HPV E6/E7 mRNA and HC2-HPV-DNA in cervical screening project. METHODS: We detected both HPV E6/E7 mRNA and HC2-HPV-DNA of each sample which collected from 130 cervical disease patients' cervix during Jan. 2008 and July. 2009. TCT results were taken as standard to evaluate the diagnostic accuracy of the above two test methods in detecting high-grade cervical disease. RESULTS: 82.3% (107/130)women were confirmed to infect HPV by HC2-HPV-DNA detection, and 40.0% (52/130) women were confirmed to infect HPV by HPV E6/E7 mRNA detection, there was no significant difference between the two results (chi2 = 24.5, P < 0.05). The sensitivity, specificity, positive predictive value, negative predictive value of HC2-HPV-DNA detection were 90.1%, 22.1%, 37.4% and 82.6%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value of HPV E6/E7 mRNA detection were 65.9%, 73.3%, 55.8% and 80.8%, respectively. CONCLUSION: In clinical cervical screening project of single time, the combination of HC2-HPV-DNA detection and HPV E6/E7 mRNA detection wick take on more potential value than applying each of them alone. RNA;