APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Qingqing Li,Zhiwei Sun,Yilin Wei,Zixu Ma,Liucheng Wang,Renfeng Nie
Reversible hydrogen storage via Liquid organic hydrogen carriers (LOHCs) is one of the key technologies for efficient utilization of hydrogen energy. How to construct efficient dehydrogenation/hydrogenation catalysts that enable low-temperature catalysis still remains challenging. Herein, we present the design and construction of single-atom Co-N-C(x) catalysts allowing significantly improved acceptorless dehydrogenation of 1,2,3,4-tetrahydroquinoline (THQ). By varying the ligand/Co ratio, the optimal Co-N-C(1.5) can achieve 97.5% dehydrogenated product and 0.82 h −1 TOF value at ambient temperature, overperforming many reported non-noble metal even noble metal catalysts. This catalyst exhibits good recyclability and substrate versatility, enabling ambient temperature dehydrogenation of various N-heterocycles and efficient reverse hydrogenation of aromatic N-heterocycles, thus achieving the loop of reversible hydrogen storage. The active catalyst centers consist of specific Co-N x moieties and nitrogen species within the carbon support. Controlled experiments reveal that the different performance of Co-N-C(x) is determined by density of the Co-N x , and the rate-determining step of THQ dehydrogenation is correlated with the bond cleavages in surface-bound THQ. This work offers a promising pathway for energy-efficient and cost-effective hydrogen energy utilization under practical conditions.
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RSC Advances
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2017
·Vol. 7
·期 15
·9381-9392
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IF 3.108
Qiao Wang,Chandra Sekhar Biswas,Massimiliano Galluzzi,Yuhang Wu,Bing Du,Florian. J. Stadler
Random copolymer gels of N-isopropylacrylamide (NIPAM) and N-ethylacrylamide (NEAM) were synthesized using a 1 : 1 monomer molar ratio in different methanol–water (xm = 0, 0.06, 0.13, 0.21, 0.31 0.43, 0.57, 0.76, where xm = mole fraction of methanol) mixtures. The samples were characterized using different techniques like Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), swelling ratio measurements, deswelling kinetics study, atomic force microscopy (AFM), and rheology. We found that, with the variation of the solvent composition (methanol–water mixtures) the properties of the gels varied significantly. These results can be explained on the basis of the interactions of the two different kinds of monomers with different methanol–water mixtures, their different kinds of thermoresponsiveness and hydrophilicity, and their different cononsolvent properties toward methanol–water mixtures.
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Journal of Environmental Sciences
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2016
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IF 2.208
Xingdu Chen,Chengjian Yang,Weiwei Wang,Bizhou Ge,Jun Zhang,Yucan Liu,Yaping Nan
The biodegradation characteristic and potential metabolic pathway for removal of environmental N,N-dimethylacetamide (DMAC) by Rhodococcus sp. strain B83 was studied. Rhodococcus sp. strain B83 was isolated from the rhizosphere of a pagoda tree and proved capable of utilizing DMAC as sole source of carbon and nitrogen. Batch culture studies showed that strain B83 could tolerate up to 25 g/L DMAC and showed distinct growth on possible catabolic intermediates except for acetate. The nitrogen balance analysis revealed that approximately 71% of the initial nitrogen was converted to organic nitrogen. DMAC degradation has led to accumulation of acetate and organic nitrogen, meanwhile traces of nitrate and ammonia was build-up but without nitrite. The growth of strain B83 could be inhibited by adding exogenous acetate. By means of the assay of enzymatic degradation of DMAC, several catabolic intermediates at different intervals were observed and identified. Based on the results obtained from culture solution and enzymatic degradation assay, a detailed pathway is proposed for DMAC biodegradation.
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JOURNAL OF PHARMACEUTICAL SCIENCES
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2016
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IF 2.641
Hongyan Zhu,Jie Cao,Sisi Cui,Zhiyu Qian,Yueqing Gu
ABSTRACT 10-Hydroxycamptothecin (HCPT) is an effective anticancer drug against various types of solid tumors . But the antitumor efficacy of HCPT is far from satisfactory because of its poor physicochemical properties, short circulating half-life, low stability, and nonspecific toxicity to normal tissues. Therefore, a targeted delivery strategy for HCPT to pathological sites is eagerly needed to overcome these limitations. The folate-modified N-succinyl-N′-octyl chitosan (folate-SOC) micelle was chosen in this study and served as the targeted delivery system for HCPT to improve the antitumor efficacy. The water-insoluble anticancer drug HCPT was encapsulated into the folate-SOC micelles by the dialysis method. The near- spherical HCPT-loaded folate-SOC (HCPT/folate-SOC) micelles were formed in aqueous media with diameter of about 100-200 nm. The HCPT/folate-SOC micelles displayed a good stability, reasonable drug-loading content (about 10%), and sustained release behavior for the water- insoluble HCPT. Compared with free HCPT, HCPT/folate-SOC micelles exhibited a significant enhancement of cellular uptake, higher cytotoxicity against folate receptor positive tumor cell (Bel-7402), excellent tumor-targeting capability and substantially better antitumor efficacy on the nude mice bearing Bel-7402 xenografts. These results demonstrate the potential of folate- SOC micelles as long-term stable and effective drug delivery systems in cancer therapy.
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AGRICULTURE ECOSYSTEMS & ENVIRONMENT
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2017
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IF 4.099
Congyan Wang,Jiawei Zhou,Jun Liu,Kun Jiang,Daolin Du
Soil N-fixing bacteria communities (SNB) can increase soil N availability, which can facilitate invasions of many kinds of invasive plant species. Meanwhile, variability in the forms of anthropogenic N deposition can mediate obvious shifts in both soil physicochemical properties and soil microbial communities (especially SNB). This can alter the soil micro-ecological mechanisms of plant invasions via changes in soil characteristics and soil microbial communities, especially SNB. This study uses next-generation high throughput sequencing technology to provide insight into the effects of invasion by Amaranthus retroflexus L. on the structure and diversity of SNB under different forms of simulated N deposition (SND). Soil pH under A. retroflexus invasion under various forms of SND was 8.08% lower than controls under a NH 4 -N treatment ( P < 0.05), 15.15% lower than controls under a NO 3 -N treatment ( P < 0.05), and 6.57% lower than controls under CO(NH 2 ) 2 -N and Mix-N treatments ( P < 0.05). Meanwhile, soil pH was one of the most important environmental variables explaining changes in the structure and diversity of SNB. The total number of species of SNB under A. retroflexus invasion was approximately 13.13% higher than controls for the NH 4 -N treatment ( P > 0.05), 11.00% higher than controls for the NO 3 -N treatment ( P > 0.05), 39.42% higher than controls for the CO(NH 2 ) 2 -N treatment ( P < 0.05), and 27.67 higher than controls for the Mix-N treatment ( P < 0.05). The positive effects mediated by the combined treatments of A. retroflexus invasion and SND may be ascribed to enhanced soil nutrient content (especially N), which can enhance the abundance of the nifH gene. The effects of A. retroflexus invasion on the total number of species of SNB under organic and mixed-N addition were greater than under inorganic N addition. This may be a consequence of a disturbance of the balance of inorganic to organic N for SND, as a result of the addition of a single form of inorganic N, which can diminish the stimulatory effects of soil nutrient content on SNB under inorganic N. Another potential cause of this pattern may be stronger acidification under inorganic N addition, which can exert more pronounced effects on SNB. LEfSe analysis showed that some species changed significantly under A. retroflexus invasion in the presence of SND (i.e., Rhodobacteraceae under NH 4 -N and Proteobacteria under CO(NH 2 ) 2 -N). Thus, A. retroflexus invasion in the presence of SND caused obvious shifts in certain species of SNB and increased the total number of species of SNB in particular, to facilitate its further invasion.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 131
·期 17
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IF 1.64
Hongming Yuan,Zaochuan Ge,Shaojun Chen,Shiguo Chen,Haipeng Yang,Haitao Zhuo
This article demonstrates a comparative investigation about the effect of diisocyanate on pyridine containing shape memory polyurethanes (Py-SMPUs), which are synthesized with N , N -bis(2-hydroxylethyl)isonicotinamide (BINA) and four different diisocyanates: 1,6-hexanediisocyante (HDI), isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI), and tolylene diisocyanate (TDI). Results show that all BINA–SMPU systems have amorphous reversible phase. Comparatively, the MDI–BINA and TDI–BINA systems show higher T g ; and the HDI–BINA and IPDI–BINA systems show better thermal stability. In addition, the HDI–BINA and the IPDI–BINA systems exhibit good thermal-induced shape memory effect and good moisture-sensitive shape memory effect due to their better moisture absorption properties. Particularly, the HDI–BINA system has better response speed and better shape recovery. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40721.
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EUROPEAN POLYMER JOURNAL
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2013
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IF 2.562
Xiaohong Wang,Guohua Jiang,Zhen Wei,Xia Li,Bolin Tang
The CO 2 stimulus-sensitive nanoparticles based on poly( N , N -dimethylaminoethyl methacrylate)- b -poly styrene (PDMAEMA- b -PS) were prepared via surfactant-free miniemulsion reversible addition–fragmentation chain transfer (RAFT) polymerization. The as-prepared nanoparticles exhibited core–shell structure with about 120 nm in diameter. Their dispersion/aggregation in water can be adjusted by alternatively bubbling of CO 2 and N 2 . Drug release from these nanoparticles can be accelerated (or delayed) by bubbling (or removing) of CO 2 .
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Polymer Chemistry
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2013
·Vol. 4
·期 14
·3963-3967
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IF 5.231
Guoyan Zhang,Jibin Zhang,Bai Yang
Polymerizable ZnS nanoparticles (NPs) were fabricated in N,N′-dimethylacrylamide via a novel facile and effective strategy, and a series of transparent bulk nanocomposites were also prepared based on such polymerizable ZnS NPs. The structure, surface chemistry and distribution of the polymerizable ZnS NPs were studied by powder XRD, FTIR, 1H NMR and TEM. The results indicated that we have successfully synthesized the polymerizable ZnS NPs with an average size of 4–5 nm by the innovatory method and the surface of these NPs were terminated with phenyl and vinyl groups which made sure of the good dispersion in the monomers. The polymerizable ZnS NPs could be easily polymerized with the monomers and fabricated a series of bulk nanocomposites. The obtained bulk nanocomposites (3 mm) exhibit good transmittance in the visible range and its refractive index are in the range from 1.527 to 1.598 in 632.8 nm by changing the content of the polymerizable ZnS NPs from 0 to 11.1 wt%. This novel strategy opens a new gate to produce transparent bulk nanocomposites with tunable refractive indices for potential optical device applications.
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REPRODUCTIVE TOXICOLOGY
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2025
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IF 2.8
Huage Liu
Thirdhand smoke (THS), a residual cigarette smoke still remaining in indoor environment long after active smoking has ceased, has aroused more and more people’s attention on health. However, the impact of THS exposure on the male reproductive system, particularly in in-vivo study, remain unclear. Thus, this study aims to investigate the adverse effects of 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA), a special component in THS, on testis. Herein, adult ICR mice were orally administered diluted dimethylsulfoxide (control), 0.075 μg/kg and 0.15 μg/kg NNA for 10 weeks. The findings revealed that NNA exposure, especially in 0.15 μg/kg dosage, significantly reduced the epithelium height and tubular area within the testis. Transcriptomic analysis indicated that NNA exposure interfered with the expression of genes associated with oxygen transport and oxygen binding processes, such as Hbb-bs , the downregulation of which also led to oxidative damage. Additionally, NNA exposure induced oxidative damage in testis by decreased levels of SOD and GSH enzymes, along with an increase in MDA level. In summary, our results demonstrate that NNA exposure causes impaired testicular structure and oxidative damage, indicating its testicular toxicity. This finding not only implies the detrimental effect of NNA on male reproduction, but also provides a fundamental basis for further research on the impact of THS exposure on male reproductive health.
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Nature Communications
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2025
·Vol. 16
·期 1
·1-12
·
IF 15.7
Yang Liu,Pu Zhongji,Wu Jianping,Liu Xiaofeng,Wang Zhe,Yu Haoran,Wang Liuwei,Meng Yan,Xu Gang,Yang Lirong,Zheng Wenlong
N -oxidation of N -heterocycles is essential in the synthesis of natural products but challenging due to low efficacy and poor regioselectivity. In this study, the N -oxidation selective potential of P450BM3 from Bacillus megaterium for N -heterocyclic compounds is investigated. Here, twelve amino acids located in the active center, including A74, L75, V78, A82, F87, I263, A264, A328, P329, A330, I401, and L437, are investigated by site-saturation mutation. As a result, F87, A264, L75, V78, A328, I401, and L437 are identified as hotspot residues. Subsequently, the combinatorial active-site saturation test/iterative saturation mutagenesis strategy is performed. Using quinoline as a model substrate, the mutant F87G/A264G/A328L exhibits N -oxidation selectivity of up to 99.0%, with a conversion rate of 99.3%. Molecular dynamics simulations uncover a “push-pull” molecular mechanism elucidating the pivotal role of steric factors in determining substrate recognition and N -oxidation selectivity. This study provides an efficient N -oxide synthesis method and insights into P450BM3’s molecular mechanisms.
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JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
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2024
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IF 3.6
Dongyan Yang,Lei Ni,Luping Gu,Qiang Chen,Juncheng Jiang,Jimi Su
Thermal runaway accounts for a high proportion of chemical safety accidents and poses a serious threat to the operational safety of personnel. Phase change materials (PCMs) have a high enthalpy of melting, if the latent heat energy of their phase change can be stored and used to absorb the heat released during thermal runaway, this phenomenon can provide a new approach for the control of reaction thermal runaway. In this work, microencapsulated phase change materials (microPCMs) were prepared by the suspension polymerization method using n -octadecane as the core material and polystyrene (PS) as the shell material. The prepared microPCMs had regular spherical morphologies with smooth surfaces, and the average particle size was 7.54 μm, the thermal conductivity was 0.05964 W/m∙K. The melting enthalpy of the microPCMs was 142.2 J/g, and the encapsulation percentage of the PCMs was 62.15%. The synthesis of the n -butylmagnesium bromide Grignard reagent occurred via a strong exothermic reaction, which was very likely to lead to overpressure venting once control was lost. The prepared microPCMs were applied as inhibitors in this reaction to investigate the temperature control effect under different operating conditions. The results showed that the amount of microPCMs added, and the timing of the addition affected the control effect. The addition of microPCMs could effectively reduce the reaction temperature and slow the rate of temperature increase. Even in the event of an emergency situation, such as a control failure, time could be gained for other emergency measures, effectively reducing the probability of thermal runaway accidents.
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ACS Nano
·
2022
·
IF 18.027
Yujun Zhang,Shenghua Ye,Min Gao,Yong Li,Xuan Huang,Jun Song,Hong Cai,Qianling Zhang,Junmin Zhang
Heterogenization of homogeneous catalysis through supported single-atom catalysts (SACs) provided a feasible solution to recycling catalysts while keeping its efficiency in chemical synthesis. In this work, Cu SACs anchored on N-doped graphene (Cu SACs/NG) were prepared and first used for C–N coupling reactions. During the preparation, Cu–N–C structures, including Cu–N4 moieties, were formed in a one-step pyrolysis method. As-prepared Cu SACs/NG exhibited excellent catalytic activity toward C–N coupling reactions with a broad scope of substrates and showed outstanding performance of recycling. Compared with Cu nanoparticles (Cu NPs/NG), the advantages of single-atom catalysts were validated via experimental and theoretical calculations. The enhanced performances were attributed to increasing the number of active sites and increasing the intrinsic activity of each active site. This work provides an alternative synthetic strategy for fabricating atomically dispersed SACs and represents a significant advance for coupling reactions.
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