Ultralow Energy Consumption Angstrom-Fluidic Memristor.

The emergence of nanofluidic memristors has made a giant leap to mimic the neuromorphic functions of biological neurons. Here, we report neuromorphic signaling using Angstrom-scale funnel-shaped channels with poly-l-lysine (PLL) assembled at nano-openings. We found frequency-dependent current-voltage characteristics under sweeping voltage, which represents a diode in low frequencies, but it showed pinched current hysteresis as frequency increases. The current hysteresis is strongly dependent on pH values but weakly dependent on salt concentration. We attributed the current hysteresis to the entropy barrier of PLL molecules entering and exiting the Angstrom channels, resulting in reversible voltage-gated open-close state transitions. We successfully emulated the synaptic adaptation of Hebbian learning using voltage spikes and obtained a minimum energy consumption of 2-23 fJ in each spike per channel. Our findings pave a new way to mimic neuronal functions by Angstrom channels in low energy consumption.

Spatial characteristics and dynamic differences of power industry's low carbon transition efficiency.

The power industry's low carbon transition is pivotal for achieving carbon reduction and sustainable development. This study uses the super epsilon-based measurement (Super-EBM) model and the Malmquist index to evaluate the power industry's low carbon transition efficiency using data from 30 provinces in China from 2010 to 2020, and utilizes the Tobit model to comprehensively analyze the factors affecting the low carbon transition of power industry. In addition, this paper examines the spatial differences in the power industry's low carbon transition efficiency as well as its distributional characteristics and dynamic evolutionary patterns. Conclusion is drawn as follows this paper analyzes the regional differences, spatial distribution characteristics and dynamic evolutionary trends of the power industry's low carbon transition. The main conclusions are as follows: (1) The power industry's low carbon transition efficiency in China shows an uptrend, with the western China region having the highest overall level of efficiency, greater fluctuations in the central China region, and more stability in the eastern China region, technological progress is a central factor in increasing total factor productivity, the efficiency of the power industry's low carbon transition is positively influenced by the electricity prices, and negatively influenced by the energy structure, environmental regulations and economic structure; (2) the Intraregional differences and hypervariable density are the main reasons sources of the overall differences in the efficiency of the power industry's low carbon transition; Intraregional differences in the eastern, central, and western China regions are decreasing year by year, but the efficiency of the power industry's low carbon transition in the western China region is still distributed in a multipolar way; (3) The dynamic evolutionary trends of the efficiency distribution of the low carbon transition in power industry is influenced by the type of spatial lag in the neighboring area. Where areas with low efficiency makes it difficult to achieve short-term leapfrog development, and areas with a cluster of high-efficiency provinces are prone to "Siphon Effect". The findings provide a theoretical basis for promoting the efficiency of the power industry's low carbon transition and coordinating the strategic adjustment of economic and environmental green development.

Memristive Characteristics in an Asymmetrically Charged Nanochannel.

The emergent nanofluidic memristor provides a promising way of emulating neuromorphic functions in the brain. The conical-shaped nanopore showed promising features for a nanofluidic memristor, inspiring us to investigate the memory effects in asymmetrically charged nanochannels due to their high current rectification, which may result in good memory effects. Here, the memory effects of an asymmetrically charged nanofluidic channel were numerically simulated by Poisson-Nernst-Planck equations. Our results showed that the I-V curves represented a diode in low scanning frequency and then became a memristor and finally a resistor as frequency increased. We successfully replicated the learning behavior in our system with history-dependent ion redistribution in the nanochannel. Some critical factors were quantitatively analyzed for the memory effects including voltage amplitude, optimal frequency, and Dukhin number. Experimental characterizations were also carried out. Our findings are useful for the design of nanofluidic memristors by the principle of enrichment and depletion as well as the determination of the best memory settings.

Enhanced in vitro invasiveness and drug resistance with altered gene expression patterns in a human lung carcinoma cell line after pulse selection with anticancer drugs.

The human lung carcinoma cell line DLKP was exposed to sequential pulses of 10 commonly used chemotherapeutic drugs (VP-16, vincristine, taxotere, mitoxantrone, 5-fluorouracil, methotrexate, CCNU, BCNU, cisplatin and chlorambucil); resulting cell lines exhibited resistance to the selecting agents (ranging approx. 1.5- to 36-fold) and, in some cases, cross-resistance to methotrexate (approx. 1.4- to 22-fold), vincristine (1.6- to 262-fold), doxorubicin (Adriamycin, approx. 1.1- to 33-fold) and taxotere (approx. 1.1- to 36-fold). Several of the variants displayed collateral sensitivity to cisplatin. A marked increase in in vitro invasiveness and motility was observed with variants pulsed with mitoxantrone, 5-fluorouracil, methotrexate, BCNU, cisplatin and chlorambucil. There was no significant change in invasiveness of cells pulsed with VP-16, vincristine, taxotere or CCNU. All of the pulse-selected variants showed elevated levels of MDR-1/P-gp protein by Western blot analysis, although mdr-1 mRNA levels were not increased (except for DLKP-taxotere). In DLKP-taxotere, MRP1 protein levels were also greatly elevated, but mrp1 mRNA levels remained unchanged. BCRP was upregulated in DLKP-mitoxantrone at both the mRNA and protein levels. Gelatin zymography, Western blot and RT-PCR showed that DLKP and its variants secreted MMPs 2, 9 and 13. MMP inhibition assays suggested that MMP-2 plays a more important role than MMPs 9 and 13 in cell invasion of these DLKP drug-resistant variants in vitro. These results indicate that drug exposure may induce not only resistance but also invasiveness in cancer cells.