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As a basic structure of most polypyridinal metal complexes, [Ru(bpy) 3 ] 2+ , has the advantages of simple structure, facile synthesis and high yield, which has great potential for scientific research and application. However, sonodynamic therapy (SDT) performance of [Ru(bpy) 3 ] 2+ has not been investigated so far. SDT can overcome the tissue-penetration and phototoxicity problems compared to photodynamic therapy. Here, we report that [Ru(bpy) 3 ] 2+ is a highly potent sonosensitizer and sonocatalyst for sonotherapy in vitro and in vivo. [Ru(bpy) 3 ] 2+ can produce singlet oxygen ( 1 O 2 ) and sono-oxidize endogenous 1,4-dihydronicotinamide adenine dinucleotide (NADH) under ultrasound (US) stimulation in cancer cells. Furthermore, [Ru(bpy) 3 ] 2+ enables effective destruction of mice tumors, and the therapeutic effect can reach deep tissues over 10 cm under US irradiation. This work paves a way for polypyridinal metal complexes to be applied to the noninvasive precise sonotherapy of cancer. Sonodynamic therapy has therapeutic promise due to its safety and good tissue penetration, but is currently bottlenecked due to a lack of efficient and safe sonosensitizers. Here the authors show that [Ru(bpy) 3 ] 2+ can produce singlet oxygen and sonooxidize NADH in deep tissue, and destroy mouse tumors effectively.

The limited therapeutic effect on hypoxic and refractory solid tumors has hindered the practical application of photodynamic therapy. Herein, we report our investigation of an osmium-peroxo complex ( Os2 ), which is inactive in the dark, but can release a peroxo ligand O 2 •− upon light irradiation even in the absence of oxygen, and is transformed into a cytotoxic osmium complex ( Os1 ). Os1 is cytotoxic in the presence or absence of irradiation in hypoxic tumors, behaving as a chemotherapeutic drug. At the same time, the light-activated Os2 induces photocatalytic oxidation of endogenous 1,4-dihydronicotinamide adenine dinucleotide in living cancer cells, leading to ferroptosis, which is mediated by glutathione degradation, lipid peroxide accumulation and down-regulation of glutathione peroxidase 4. In vivo studies have confirmed that the Os2 can effectively inhibit the growth of solid hypoxic tumors in mice. A promising strategy is proposed for the treatment of hypoxic tumors with metal-based drugs. Photodynamic therapy has been a promising technique for the treatment of tumours. In this manuscript, the authors report on the photoactivation of the osmium peroxo complex and its potential use for chemotherapy and photodynamic therapy under blue light irradiation against tumours in their hypoxic environment.

Camptothecin and its derivatives are widely used for treating malignant tumors. Previous studies revealed only a limited number of candidate genes for camptothecin biosynthesis in Camptotheca acuminata , and it is still poorly understood how its biosynthesis of camptothecin has evolved. Here, we report a high-quality, chromosome-level C . acuminata genome assembly. We find that C . acuminata experiences an independent whole-genome duplication and numerous genes derive from it are related to camptothecin biosynthesis. Comparing with Catharanthus roseus , the loganic acid O -methyltransferase (LAMT) in C. acuminata fails to convert loganic acid into loganin. Instead, two secologanic acid synthases (SLASs) convert loganic acid to secologanic acid. The functional divergence of the LAMT gene and positive evolution of two SLAS genes, therefore, both contribute greatly to the camptothecin biosynthesis in C. acuminata . Our results emphasize the importance of high-quality genome assembly in identifying genetic changes in the evolutionary origin of a secondary metabolite. Camptothecin is a monoterpene indole alkaloid with anti-tumor activity. Here, the authors assemble the genome of the camptothecin producing plant Camptotheca acuminata and provide insights into the evolutionary origin of camptothecin biosynthesis by comparing to the vinblastine and vincristine biosynthetic pathway in Catharanthus roseus .

Purple coneflower ( Echinacea purpurea (L.) Moench) is a popular native North American herbal plant. Its major bioactive compound, chicoric acid, is reported to have various potential physiological functions, but little is known about its biosynthesis. Here, taking an activity-guided approach, we identify two cytosolic BAHD acyltransferases that form two intermediates, caftaric acid and chlorogenic acid. Surprisingly, a unique serine carboxypeptidase-like acyltransferase uses chlorogenic acid as its acyl donor and caftaric acid as its acyl acceptor to produce chicoric acid in vacuoles, which has evolved its acyl donor specificity from the better-known 1- O -β-D-glucose esters typical for this specific type of acyltransferase to chlorogenic acid. This unusual pathway seems unique to Echinacea species suggesting convergent evolution of chicoric acid biosynthesis. Using these identified acyltransferases, we have reconstituted chicoric acid biosynthesis in tobacco. Our results emphasize the flexibility of acyltransferases and their roles in the evolution of specialized metabolism in plants. Biosynthetic pathway of chicoric acid in purple coneflower has not been fully elucidated, though the compound has been shown to have potential health benefits. Here, the authors report the involvement of both BAHD and SCPL acyltransferases in its biosynthesis and show the pathway is unique to Echinacea species.

In this study, water soluble CuO nanostructures having nanobelt, nanorod, or spindle morphologies were synthesized using aqueous solutions of Cu(NO 3 ) 2 ·3H 2 O and NaOH by adjusting the type of surface modifier and reaction temperature. The effect of morphologies of these various CuO nanostructures as water-based lubricant additives on tribological properties was evaluated on a UMT-2 micro-friction tester, and the mechanisms underlying these properties are discussed. The three different morphologies of CuO nanostructures exhibited excellent friction-reducing and anti-wear properties. Tribological mechanisms differed in the initial stage of frictional interactions, but in the stable stage, a tribochemical reaction film and adsorbed lubricious film on the rubbing surfaces played important roles in hindering direct contact between friction pairs, leading to improved tribological properties.

A magnetic ionic liquid (abridged as MIL) [C 6 mim] 5 [Dy(SCN) 8 ] was prepared and used as the magnetic lubricant of a steel-steel sliding pair. The tribological properties of the as-prepared MIL were evaluated with a commercially obtained magnetic fluid lubricant (abridged as MF; the mixture of dioctyl sebacate and Fe 3 O 4 , denoted as DIOS-Fe 3 O 4 ) as a control. The lubrication mechanisms of the two types of magnetic lubricants were discussed in relation to worn surface analyses by SEM-EDS, XPS, and profilometry, as well as measurement of the electric contact resistance of the rubbed steel surfaces. The results revealed that the MIL exhibits better friction-reducing and antiwear performances than the as-received MF under varying test temperatures and loads. This is because the MIL participates in tribochemical reactions during the sliding process, and forms a boundary lubrication film composed of Dy 2 O 3 , FeS, FeSO 4 , nitrogen-containing organics, and thioether on the rubbed disk surface, thereby reducing the friction and wear of the frictional pair. However, the MF is unable to form a lubricating film on the surface of the rubbed steel at 25 °C, though it can form a boundary film consisting of Fe 3 O 4 and a small amount of organics under high temperature. Furthermore, the excessive Fe 3 O 4 particulates that accumulate in the sliding zone may lead to enhanced abrasive wear of the sliding pair.

Counties are important vehicles for implementing the new-type urbanization strategy in China. However, some counties are experiencing population shrinkage and ageing, and the decline in the working-age population will constrain the process of new-type urbanization, but this has not received sufficient attention from academia and government policymakers. This paper takes Jilin Province, China, which is experiencing significant population shrinkage and ageing, as a case study to examine the spatial–temporal characteristics of population shrinkage and ageing at the county level and their relationship with new-type urbanization. This study found the following: (1) From 2014 to 2020, counties in Jilin Province experienced significant population shrinkage and ageing. (2) There is a certain correlation between population shrinkage and ageing. Ageing is the most obvious in counties with moderate shrinkage, followed by counties with mild shrinkage. (3) Although a new-type urbanization strategy has been implemented, the level of new-type urbanization in counties with population shrinkage and ageing is generally low and shows a trend of rising first and then falling. (4) Population shrinkage and ageing are positively correlated with new-type urbanization. The more severe the population shrinkage or ageing, the lower the level of new-type urbanization. It is necessary to take measures to alleviate the new-type urbanization dilemma in areas with population shrinkage and ageing, in order to promote sustainable regional development.

This paper develops a conceptual model and an indicator system for measuring economic resilience of resource-based cities based on the theory of evolutionary resilience and the related concepts of persistence, adaptation, and transformation. Nineteen resource-based cities in Northeast China were analyzed using the indicator system. The results showed that Liaoning and Jilin provinces had higher economic resilience than Heilongjiang Province. Panjin, Benxi, and Anshan in Liaoning Province were the top three cities, while Shuangyashan and other coal-based cities in Heilongjiang Province ranked last. Metals-and petroleum-based cities had significantly higher resilience than coal-based cities. The differences in persistence, adaptability, transformation, and resilience among resource-based cities decreased since the introduction of the Northeast Revitalization Strategy in 2003. Forestry-based cities improved the most in terms of resilience, followed by metals-based and multiple-resource cities; however, resilience dropped for coal-based cities, and petroleum-based cities falling the most. The findings illustrate the importance and the way to develop a differentiated approach to improve resilience among resource-based cities.

Oleylamine (hereinafter referred to as OM)-modified CeO 2 nanoparticles were synthesized by a one-pot pyrolysis method. The tribological properties of the as-prepared CeO 2 nanoparticles as the lubricant additive in poly-alpha olefin (PAO) were investigated with a four-ball machine, and their lubricating mechanism was discussed in relation to worn surface analyses by SEM, EDS, and XPS. Findings indicate that these nanoparticles exhibit good dispersibility as well as excellent anti-wear ability in PAO. This is because OM-modified CeO 2 nanoparticles can catalyze the oxidation of metallic Fe to form ferrite oxide-containing tribo-film. Under the condition of ASTM D2266-2001, the same lowest WDS was obtained at the concentration of 0.2 wt% and 1.8 wt%. When the concentration of CeO 2 is 0.2 wt%, a compact catalytic oxidation tribo-film is formed, which has more outstanding long-term anti-wear ability. When 1.8 wt% CeO 2 is added, the tribo-film formed is the combination of catalytic oxidation film and ceria deposition film, which has more significant bearing capacity.

CeO 2 nanoparticles are potential anti-wear additives because of their outstanding anti-wear and load-bearing capacity. However, the shear-sintering tribo-film formation mechanism of oxide nanoparticles limits the tribo-film formation rate and thickness greatly. In this study, by compounding with zinc dioctyl dithiophosphate (ZDDP), ultra-fine CeO 2 nanoparticles modified with oleylamine (OM) can quickly form 2 µm ultra-thick tribo-film, which is 10–15 times thicker than that of ZDDP and CeO 2 , respectively. The ultra-thick tribo-film presents a nanocomposite structure with amorphous phosphate as binder and nano-CeO 2 as filling phase, which leads to the highest loading capacity of composite additives. The results of adsorption experiments tested by dissipative quartz crystal microbalance (QCM-D) showed that the P B value of additive has nothing to do with its equilibrium adsorption mass, but is directly proportional to its adsorption rate in 10 s. The compound additive of CeO 2 and ZDDP presented the co-deposition mode of ZDDP monolayer rigid adsorption and CeO 2 viscoelastic adsorption on the metal surface, which showed the highest adsorption rate in 10 s. It is found that the tribo-film must have high film forming rate and wear resistance at the same time in order to achieve super thickness. Cerium phosphate was formed from ZDDP and CeO 2 through tribochemistry reaction, which promotes the formation of an ultra-thick tribo-film with nanocomposite structure, which not only maintains the low friction characteristics of CeO 2 , but also realizes high P B and high load-carrying capacity.