All Solution-Processed Inorganic, Multilevel Memristors Utilizing Liquid Metals Electrodes Suitable for Analog Computing.

Herein, we report a solution-processable memristive device based on bismuth vanadate (BiVO4) and titanium dioxide (TiO2) with gallium-based eutectic gallium-indium (EGaIn) and gallium-indium-tin alloy (GaInSn) liquid metal as the top electrode. Scanning electron microscopy (SEM) shows the formation of a nonporous structure of BiVO4 and TiO2 for efficient resistive switching. Additionally, the gallium-based liquid metal (GLM)-contacted memristors exhibit stable memristor behavior over a wide temperature range from -10 to +90 °C. Gallium atoms in the liquid metal play an important role in the conductive filament formation as well as the device's operation stability as elucidated by I-V characteristics. The synaptic behavior of the GLM-memristors was characterized, with excellent long-term potentiation (LTP) and long-term depression (LTD) linearity. Using the performance of our device in a multilayer perceptron (MLP) network, a ∼90% accuracy in the handwriting recognition of modified national institute of standards and technology database (MNIST) was achieved. Our findings pave a path for solution-processed/GLM-based memristors which can be used in neuromorphic applications on flexible substrates in a harsh environment.

Financial Budgets of Technology-Based SMEs From the Perspective of Sustainability and Big Data.

In this contemporary world, the words data and sustainability play a crucial role in determining the financial budgets of small and medium-sized enterprises (SMEs). Usually, it is stated that the survival of small and medium-sized enterprises (SMEs) is directly proportional to the growth and sustainability factor of the nation. The economic sustainability of a nation is dependent on appropriate functioning of SMEs. Any kind of direct impact on the working of SMEs will have its impact on the whole economy of a nation. There are different factors such as lack of financial capacity, low market demands, restrictions with regard to the capital, and barriers in the supply chain that affect the sustainability of SMEs worldwide. Nevertheless, small, and medium sized enterprises around the world are greatly investing on skills, innovation, and other capital related resources to mark up the demands of the external market. The main objective of this study is to examine the financial budgets of technology-based SMEs from the perspective of sustainability and big data. For this, the study collects data through a questionnaire from 1,800 Small and Medium Sized Enterprises. Based on a detailed and careful examination of the data, only 1,400 of the responses received were considered valid (79.75%). To test the hypothesis stated, the study employs structural equation modeling. This will help the researcher to examine the direct effect of financial budget and technology adaption of SMEs from the perspective of sustainability and big data. Results of the study stated that SMEs sustainability and big data are directly and positively related to the financial budget planning of technology-based SMEs. The study also found that big data plays an important role in the businesses, specifically for their own growth.

Discovery of 2-aminothiazolyl berberine derivatives as effectively antibacterial agents toward clinically drug-resistant Gram-negative Acinetobacter baumanii.

Aminothiazolyl berberine derivatives as potentially antimicrobial agents were designed and synthesized in an effort to overcome drug resistance. The antimicrobial assay revealed that some target compounds exhibited significantly inhibitory efficiencies toward bacteria and fungi including drug-resistant pathogens, and the aminothiazole and Schiff base moieties were helpful structural fragments for aqueous solubility and antibacterial activity. Especially, aminothiazolyl 9-hexyl berberine 9c and 2,4-dichlorobenzyl derivative 18a exhibited good activities (MIC = 2 nmol/mL) against clinically drug-resistant Gram-negative Acinetobacter baumanii with low cytotoxicity to hepatocyte LO2 cells, rapidly bactericidal effects and quite slow development of bacterial resistance toward A. baumanii. Molecular modeling indicated that compounds 9c and 18a could bind with GLY-102, ARG-136 and/or ALA-100 residues of DNA gyrase through hydrogen bonds. It was found that compounds 9c and 18a were able to disturb the drug-resistant A. baumanii membrane effectively, and molecule 9c could not only intercalate but also cleave bacterial DNA isolated from resistant A. baumanii, which might be the preliminary antibacterial action mechanism of inhibiting the growth of A. baumanii strain. In particular, the combination use of compound 9c with norfloxacin could enhance the antibacterial activity, broaden antibacterial spectrum and overcome the drug resistance.

Total Synthesis of Lycopodium Alkaloids Palhinine A and Palhinine D.

The first total syntheses of Lycopodium alkaloids palhinine A, palhinine D, and their C3-epimers have been divergently achieved through the use of a connective transform to access a pivotal hexacyclic isoxazolidine precursor. A microwave-assisted regio- and stereoselective intramolecular nitrone-alkene cycloaddition was tactically orchestrated as a key step to install the crucial 10-oxa-1-azabicyclo[5.2.1]decane moiety embedded in the conformationally rigid isotwistane framework, demonstrating the feasibility of constructing the highly strained medium-sized ring by introduction of an oxygen bridging linker to relieve the transannular strain in the polycyclic scaffold. Subsequent N-O bond cleavage provided the synthetically challenging nine-membered azonane ring system bearing the requisite C3 hydroxyl group. Late-stage transformations featuring a chemo- and stereoselective reduction of the pentacyclic ß-diketone secured the availability of our target molecules.

Enantioselective synthesis of Amaryllidaceae alkaloids (+)-vittatine, (+)-epi-vittatine, and (+)-buphanisine.

Cat. on a hot tin roof: Enantioselective catalytic Michael addition of α-cyanoketones to acrylates under bifunctional organocatalysis was used to construct the unique arylic all-carbon quaternary stereocenter, which is synthetically crucial in the chemical synthesis of optically pure cis-aryl hydroindole alkaloids. The protocol offers an asymmetric route to (+)-vittatine, (+)-epi-vittatine, and (+)-buphanisine.

Toward the total synthesis of palhinine A: expedient assembly of multifunctionalized isotwistane ring system with contiguous quaternary stereocenters.

The stereoselective, expedient assembly of the key functionalized isotwistane (bridged tricyclo[4.3.1.0(3,7)]decane) system, 5/6/6 ring, with contiguous quaternary stereocenters in Lycopodium alkaloid palhinine A and its analogues via an intramolecular Diels-Alder strategy is described.

Asymmetric synthesis of bioactive hydrodibenzofuran alkaloids: (-)-lycoramine, (-)-galanthamine, and (+)-lunarine.

Divergent route: a direct C-C bond-forming approach to the key aryl-substituted all-carbon quaternary stereogenic center present in bioactive hydrodibenzofuran alkaloids has been discovered. This approach involves an unprecedented organocatalytic enantioselective Michael addition of α-cyanoketones with acrylates and was used in a novel and divergent synthetic strategy for the title compounds in asymmetric fashion.