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Two previously undescribed B-ring seco -limonoids named toonacilinatin I (1) and toonacilinatin J (2), together with ten known analogues (3 – 12), were isolated from the ethyl acetate extract of the bark of Toona ciliata var pubescens. All structures were elucidated by extensive spectroscopic analysis involving IR, MS, and NMR. Among them, compounds 1 – 10 , and 12 were discovered from this plant for the first time. All the compounds except 7 and 8 were evaluated for their anti-tumor activity by MTT method of MDA-MB-231 and A-673 cell lines, the bioassay results showed that compounds 1 , 2 , 5 , 9 and 11 exerted superior inhibitory activity with IC 50 values as 0.11–1.60 μ M. Notably, those active compounds exhibited little effect on normal hepatocellular HL-7702 cells. [Display omitted] • Twelve limonoids including two previously undescribed B-ring seco -limonoids were isolated. • All isolated compounds except 7 and 8 were evaluated anti-tumor activity of MDA-MB-231, A-673 cell lines. • Compounds 1 , 2 , 5 , 9 and 11 showed superior cytotoxicity against two tested cancer cell lines with IC 50 values as 0.11–1.60 μ M. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The orphan nuclear receptor Nur77 (also known as TR3 or nerve growth factor-induced clone B NGFI-B) functions as a nuclear transcription factor in the regulation of target gene expression and plays a critical role in the regulation of differentiation, proliferation, apoptosis, and survival of many different cell types. Recent studies demonstrate that Nur77 also involves many important physiological and pathological processes including cancer, inflammation and immunity, cardiovascular diseases, and bone diseases. Our previous studies showed that cardiac glycosides could induce the expression of Nur77 protein and its translocation from the nucleus to the cytoplasm and subsequent targeting to mitochondria, leading to apoptosis of cancer cells. In order to probe the Nur77 protein inducting pathway, we designed and synthesized a series of novel biotinylated cardiac glycosides from β-Antiarin and α-Antiarin, two typical cardiac glycosides from the plant of Antiaris toxicaria. The induction of Nur77 protein expression of these biotinylated cardiac glycosides and their inhibitory effects on NIH-H460 cancer cell proliferation were evaluated. Results displayed that some biotinylated cardiac glycosides could significantly induce the expression of Nur77 protein comparable with their parent compounds β-Antiarin and α-Antiarin. Also, their streptavidin binding activities were evaluated. Among them, biotinylated cardiac glycosides P4b and P5a exhibited significant effect on the induction of Nur77 expression along with high binding capacity with streptavidin, suggesting that they can be used as probes for probing Nur77 protein inducting pathway. [ABSTRACT FROM AUTHOR]

Abstract In nature, microbes use extracellular electron transfer (EET) to recover noble metals. Most attention has been paid to the biorecovery process occurring intracellularly and on the cell surface. In this work, we report that Pd nanorods could be biosynthesized by Enterobacter cloacae SgZ-5T in the extracellular space. This bacterium possesses both a direct EET pathway through membrane redox systems and an indirect EET pathway via the self-secreted electron carrier hydroquinone (HQ). When exposed to Pd(II), the bacteria adjusted their metabolic pathway and membrane-bound proteins to secrete riboflavin (RF). However, no HQ was detected in the supernatant in presence of Pd(II). No significant change was observed through metabolomic analysis regarding the abundance of HQ in presence of Pd(II) compared to Pd(II)-free supernatant. Similar results were also obtained through transcriptomic analysis of YqjG gene encoding glutathionyl-HQ reductase synthase. X-ray photoelectron spectroscopic evidence indicated that HQ may adsorb to the surface of Pd nanorods. Moreover, the gene encoding RF synthase (ribE) was up-regulated in the present of Pd(II), suggesting that this bioreduction process induced RF synthase, which had been shown in previous results. The UV–vis spectroscopy data demonstrated that the Pd(II) reduction rate was enhanced by 5%, 5.5% and 30% by the addition of 3.33 μM HQ, 3.33 μM RF and the both, respectively. All these results revealed that the bi-mediators secreted by bacteria were beneficial for biorecovery of Pd. This work is of significance for understanding metal biorecovery processes and natural biogeochemical processes. Graphical abstract In this work, we report that Pd nanorods can be biosynthesized by Enterobacter cloacae SgZ-5T in the extracellular space. This bacterium possesses both directly extracellular electron transfer (EET) mode through membrane redox systems and indirect EET pathways via self-secreted mediator hydroquinone (HQ). When exposed to Pd(II), the bacteria adjust their metabolic pathways and membrane-bound proteins to secrete the other diagnosed mediator riboflavin (RF). The gene encoding RF synthase (ribE) is up-regulated in the present of Pd(II), supporting our conclusion that this bioreduction process induced RF synthase. In addition, X-ray photoelectron spectroscopic evidence indicates that HQ may adsorb to the surface of Pd nanorods. The Pd(II) reduction rate is enhanced by 5%,5.5% and 31% when 3.33 μM HQ, 3.33 μM RF and its mixed are added into the culture. Such a mechanism is of significance for understanding the metal biorecovery processes and natural biogeochemical mechanisms. Unlabelled Image Highlights • This is the first study which reporting that Pd nanorods can be biosynthesized by Enterobacter Cloacae SgZ-5T. • These biosynthesized materials in the extracellular space are suspended on the surface of the culture. • SgZ-5T utilize EET via bi-mediators, hydroquinone and riboflavin, to mediate the biorecovery of Pd nanorods. • This EET mode is of significance for understanding metal biorecovery processes and natural biogeochemical processes. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of 1-benzyl-1,4-dihydronicotinamide with a series of 1,1-di-p-substituted-phenyl-2,2-dinitroethylenes in oxygen-saturated acetonitrile produced various amounts of the corresponding ethanes and diaryl ketones according to the electronic structure of the substituent groups indicating a spectrum of intermediate mechanism between polar mechanism and SET mechanism. [Copyright &y& Elsevier]

Abstract: Biodegradation of methyl parathion (MP), a widely used organophosphorus pesticide, was investigated using a newly isolated bacterium strain Acinetobacter radioresistens USTB-04. MP at an initial concentration of 1200 mg/L could be totally biodegraded by A. radioresistens USTB-04 as the sole carbon source less than 4 d in the presence of phosphate and urea as phosphorus and nitrogen sources, respectively. Biodegradation of MP was also achieved using cell-free extract of A. radioresistens USTB-04. MP at an initial concentration of 130 mg/L was completely biodegraded in 2 h in the presence of cell-free extract with a protein concentration of 148.0 mg/L, which was increased with the increase of pH from 5.0 to 8.0. Contrary to published reports, no intermediate or final degradation metabolites of MP could be observed. Thus we suggest that the cleavage of C–C bond on the benzene ring other than P–O bond may be the biodegradation pathway of MP by A. radioresistens USTB-04. [Copyright &y& Elsevier]

Abstract Based on the idea of suppressing submicron particle escape effectively by applying magnetic field, we propose a novel model design of outer vortex electrostatic cyclone precipitator (ECP) and establish a theoretical model under four-field coupling interaction. The influences of temperature and working voltage on the escape rate of submicron particles with or without magnetic confinement effect are subsequently evaluated. The results indicate that magnetic confinement effect can availably reduce submicron particle escape in ECP. Whether magnetic field exists or not, high working voltage and low temperature are more favorable to confine submicron particles to collection wall surface, however, the increasing effect of low working voltage on the trapping performance is bigger, and the weakening effect of temperature under magnetic confinement effect is smaller than that under non magnetic field. At a certain working voltage or temperature, the enhancing effect of magnetic field on collection efficiency progressively decreases with the increasing magnetic flux density, and the smaller the magnetic flux density is, the stronger the ability of magnetic confinement becomes. The research results provide assistance for designing newly effective ECP and applying magnetic confinement technique to reduce submicron particle escape in industrial applications. Graphical abstract Unlabelled Image Highlights • A new outer vortex ECP model design is proposed by applying magnetic confinement. • A theoretical model with four-field coupling interaction is established. • The escape rate of submicron particles with or without magnetic field is explored. • Magnetic confinement effect can availably reduce the submicron particle escape. • Magnetic confinement effect is better at high temperature or low working voltage. [ABSTRACT FROM AUTHOR]

Natural gas hydrates widely distributed in marine sediments and permafrost areas have attracted global attentions as potential energy resources. The permeability of sediments with or without hydrate is an essential and critical parameter that could determine the technical and economical feasibility of gas recovery from hydrate reservoirs. The saturation of hydrate in the solid phase significantly affects the pore size, the pore volume, the distribution of reservoir pore throat size, etc., which are key factors determining the permeability of the hydrate-bearing deposit. In this study, the absolute permeability and the water effective permeability were experimentally measured with fluid water under a serials of hydrate saturations (0–31% in volume). Hydrate saturations were controlled and calculated precisely based on the amount of injected and produced gas/water, and the system pressure and temperature. Unconsolidated quartz sands with different particle size (200–300, 300–450, 450–600 µm) were used as the porous media. The absolute permeabilities of the above quartz sands were 21.11, 35.53 and 52.32 Darcies, respectively. The experimental results indicated that the characteristics of the permeability were different with the hydrate saturation lower and higher than 10%. When the hydrate saturation increased from 0 to 10%, there was a sudden drop for the permeability, which indicated that the appearance and the existence of the solid hydrate phase in the porous media affected the permeability significantly. On the other hand, this effect lightened when the hydrate saturation higher than 10%. With different hydrate crystal growth habit, a new relationship between the ratio of the permeability in the presence and the absence of hydrate and the hydrate saturation was developed. Two patterns of the pore filling models with the hydrate saturation lower and higher than 10% were used to fit the measured experimental data. The overall relationship and the values of the saturation exponent were continuous and consistent with hydrate saturation lower than 31%. [ABSTRACT FROM AUTHOR]

• Novel coupled equations of thermoelasticity in the context of large temperature changes are presented. • The effect of large temperature changes on heat transfer can be regarded as changing the specific heat. • The effect of large temperature changes will increase with the amplitude of temperature change. The accurate information of the thermal stresses and temperature in isotropic elastic solids is the key for many engineering applications. At present the classical linear coupled theory of thermoelasticity deduced with the assumptions of small temperature changes is widely used to solve the thermoelastic problems in engineering. In this paper, to describe the thermoelastic behavior in isotropic solids undergoing large temperature changes more accurately, the novel coupled models of thermoelasticity and the corresponding finite element models have been presented explicitly and validated by experimental measurement. The effect of large temperature changes on the solutions of thermoelastic problems is discussed. For the heat transfer process, if the isotropic elastic solids will expand when heated and contract when cooled and the condition d E E d T · σ i j E − δ i j 1 − 2 ν α < 0 can be met in the context of small deformations, the effect of large temperature changes can be regarded as increasing the specific heat. The proposed models are applied to solve two thermoelastic problems. From the obtained numerical results, the effect of large temperature changes will increase with the amplitude of temperature change and may be considerably even when the temperature changes slowly. [ABSTRACT FROM AUTHOR]