Synthesis, crystal structure and bioactivity of phenazine-1-carboxylic acylhydrazone derivatives

A phenazine-1-carboxylic acid intermediate was synthesized from the reaction of aniline and 2-bromo-3-nitro-benzoic acid. It was then esterified and reacted with hydrazine hydrate to afford phenazine-1-carboxylic hydrazine. Finally, 10 new hydrazone compounds 3a–3j were obtained by the condensation reaction of phenazine-1-carboxylic acid hydrazide and the respective aldehyde-containing compound. The structures were characterized by 1H and 13C NMR spectroscopy, MS and single crystal X-ray diffraction. The antitumor activity of the target compounds in vitro (HeLa and A549) was determined by thiazolyl blue tetrazolium bromide. The results showed that compound (E)-N′-(2-hydroxy-4-(2-(piperidine-1-yl) ethoxy) benzyl) phenazine-1-carbonyl hydrazide 3d exhibited good cytotoxic activity

Relative sea-level rise around East Antarctica during Oligocene glaciation

During the middle and late Eocene (∼48-34 Myr ago), the Earth's climate cooled and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarcticainduced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level rosedespite an overall reduction in the mass of the ocean caused by the transfer of water to the ice sheet. Here we identify the crustal response to ice-sheet growth by forcing a glacial-hydro isostatic adjustment model with an Antarctic ice-sheet model. We find that the shelf areas around East Antarctica first shoaled as upper mantle material upwelled and a peripheral forebulge developed. The inner shelf subsequently subsided as lithosphere flexure extended outwards from the ice-sheet margins. Consequently the coasts experienced a progressive relative sea-level rise. Our analysis of sediment cores from the vicinity of the Antarctic ice sheet are in agreement with the spatial patterns of relative sea-level change indicated by our simulations. Our results are consistent with the suggestion that near-field processes such as local sea-level change influence the equilibrium state obtained by an icesheet grounding line

Research on Industry Development Path Planning of Resource-Rich Regions in China from the Perspective of “Resources, Assets, Capital”

The development of industries in China’s resource-rich regions is mainly affected by resource reserves, environmental protection, and industrial structural adjustment. The development of resource-oriented industries that can’t support a high-quality regional economy is large but not well developed. This article considers China’s resource product imports and exports, carbon emissions, and industrial structure ratio factors in recent years. It is believed that China’s resource-rich regions have macro-level development bottlenecks, and the general development of a resource-based industries path is proposed based on the perspective of “resources, assets, and capital”. Taking Guangxi Zhuang Autonomous Region as an empirical case, this article analyzes the pattern of regional industrial development by using the input-output method, calculates the degree of inter-industrial correlation, and constructs a regional industrial development system. The results show the following: 1. China’s overall industrial development pattern has undergone major changes; 2. emerging industries and service-oriented industries have risen in development status, and although resource-based industries have a weaker development momentum, they still have an important position; 3. the hierarchical industry development management model is helpful for forming a regional circular economy innovation development pattern. The results also indicate that the integrated management of “resources, assets, and capital” has a positive effect on the development of resource-based industries in resource-rich regions, which affects the overall industrial development pattern of the region and promotes economic development

Sustainable Risk Assessment of Resource Industry at Provincial Level in China

The development of China’s resource industry is facing great pressures from industrial structure adjustment and environmental restraints, and the sustainable risk of the provincial resource industry is different. Considering the development of the resource industry and environmental pressure, this article selects the panel data of 31 provinces from 2015 to 2019 to construct an index evaluation system with six dimensions: influence, induction, supply and demand safety, regional pollution emission, environment quality, and pollution control. The results showed that Shanxi, Anhui, Jiangsu, and Shanghai had the highest sustainable risk in the resource industry, while Heilongjiang, Jilin, Tianjin, Fujian, Jiangxi, Hunan, Guizhou, Sichuan, and Qinghai had the lowest sustainable risk. The resource industry model of all the provinces is divided into sustainable, industrial, ecological, and unsustainable. Finally, this article puts forward reasonable suggestions for the four scenarios and argues that the balanced development of the resource industry sector and environmental protection is conducive to reducing the sustainable risks of the resource industry

Intracellular ATP concentration contributes to the cytotoxic and cytoprotective effects of adenosine.

Extracellular adenosine (ADE) interacts with cells by two pathways: by activating cell surface receptors at nanomolar/micromolar concentrations; and by interfering with the homeostasis of the intracellular nucleotide pool at millimolar concentrations. Ade shows both cytotoxic and cytoprotective effects; however, the underlying mechanisms remain unclear. In the present study, the effects of adenosine-mediated ATP on cell viability were investigated. Adenosine treatment was found to be cytoprotective in the low intracellular ATP state, but cytotoxic under the normal ATP state. Adenosine-mediated cytotoxicity and cytoprotection rely on adenosine-derived ATP formation, but not via the adenosine receptor pathway. Ade enhanced proteasome inhibition-induced cell death mediated by ATP generation. These data provide a new pathway by which adenosine exerts dual biological effects on cell viability, suggesting an important role for adenosine as an ATP precursor besides the adenosine receptor pathway

Facile Preparation of Co₃O₄ Hollow Dodecahedron with Superior Peroxidase-like Activity for Selective Detection of Cholesterol

The Co3O4 hollow dodecahedron (Co3O4@CN) was prepared by calcining ZIF-67 in N2 and then air atmosphere. In the Co3O4@CN compound material, Co3O4 nanoparticles (Co3O4 NPs) are anchored in the carbon skeleton, solving the aggregation problem of Co3O4 NPs. Because Co3O4@CN retains the porous structure of ZIF-67, and the presence of Co2+ and Co3+ favors electron transfer between the enzyme substrates, it has excellent peroxidase-like (POD-like) activity. Enzymatic kinetic tests show that Co3O4@CN has approximately six times more affinity for TMB than HRP and the maximal reaction rate is approximately three times that of HRP. The cholesterol sensor was constructed with Co3O4@CN, and its linear range was 20-1000 μM, and the detection limit was 14.33 μM. The application of Co3O4@CN to the detection of human serum cholesterol will be a valuable research direction

Triphenylamine Derived Radical Cations for Colorimetric Cu²⁺ Sensors and as an Antibacterial Agent

Herein, a series of triphenylamine derivatives (TPAs), which are comprised of electron donor and acceptor moieties, have been exploited as sensitive colorimetric sensors for Cu2+, operating via the formation of the corresponding organic radicals through a redox reaction in a mixed solvent system (acetonitrile/water). Further studies indicated that the Cu2+ recognition triggered organic radical cations were stable in aqueous solution, and can be used as an antibacterial agent for both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) at very low concentrations (10?7 M). On comparison with light irradiated photodynamic therapy triggered radicals, the present work reveals that the direct use of radical cations of TPAs is more convenient for practical applications in killing bacteria. This work thus provides new insight into the design of sensitive colorimetric sensors and antibacterial agents