排序方式: 共有101条查询结果,搜索用时 15 毫秒
11.
Wissam Iali Soumya S. Roy Ben J. Tickner Fadi Ahwal Aneurin J. Kennerley Simon B. Duckett 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(30):10377-10381
Hyperpolarisation methods that premagnetise agents such as pyruvate are currently receiving significant attention because they produce sensitivity gains that allow disease tracking and interrogation of cellular metabolism by magnetic resonance. Here, we communicate how signal amplification by reversible exchange (SABRE) can provide strong 13C pyruvate signal enhancements in seconds through the formation of the novel polarisation transfer catalyst [Ir(H)2(η2‐pyruvate)(DMSO)(IMes)]. By harnessing SABRE, strong signals for [1‐13C]‐ and [2‐13C]pyruvate in addition to a long‐lived singlet state in the [1,2‐13C2] form are readily created; the latter can be observed five minutes after the initial hyperpolarisation step. We also demonstrate how this development may help with future studies of chemical reactivity. 相似文献
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Nonlinear Dynamics - An initially unstable equilibrium position of a system can be stabilized by introducing a parametric excitation. This is especially of interest for suppressing self-excited... 相似文献
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Eman Al-Abbad Alakhras Fadi Anastopoulos Ioannis Das Debashis AL-Arfaj Ahlam Ouerfelli Noureddine Hosseini-Bandegharaei Ahmad 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2020,94(4):748-755
Russian Journal of Physical Chemistry A - Sorption of Ni(II) ions from liquid effluents utilizing chemically modified chitosan; (vanillin, polymer I) and (ortho-vanillin, polymer II) is studied... 相似文献
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Back Cover: Spontaneous Stepwise Self‐Assembly of a Polyoxometalate–Organic Hybrid into Catalytically Active One‐Dimensional Anisotropic Structures (Chem. Eur. J. 31/2014)
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New Perspectives for Old Clusters: Anderson–Evans Anions as Building Blocks of Large Polyoxometalate Frameworks in a Series of Heterometallic 3 d–4 f Species
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Dr. Beñat Artetxe Dr. Santiago Reinoso Dr. Leire San Felices Prof. Luis Lezama Prof. Juan M. Gutiérrez‐Zorrilla Dr. Cristian Vicent Fadi Haso Prof. Tianbo Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4616-4625
A series of nine [Sb7W36O133Ln3M2(OAc)(H2O)8]17? heterometallic anions ( Ln3M2 ; Ln=La–Gd, M=Co; Ln=Ce, M=Ni and Zn) have been obtained by reacting 3 d metal disubstituted Krebs‐type tungstoantimonates(III) with early lanthanides. Their unique tetrameric structure contains a novel {MW9O33} capping unit formed by a planar {MW6O24} fragment to which three {WO2} groups are condensed to form a tungstate skeleton identical to that of a hypothetical trilacunary derivative of the ?‐Keggin cluster. It is shown, for the first time, that classical Anderson–Evans {MW6O24} anions can act as building blocks to construct purely inorganic large frameworks. Unprecedented reactivity in the outer ring of these disk‐shaped species is also revealed. The Ln3M2 anions possess chirality owing to a {Sb4O4} cluster being encapsulated in left‐ or right‐handed orientations. Their ability to self‐associate in blackberry‐type vesicles in solution has been assessed for the Ce3Co2 derivative. 相似文献
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Chitosan loaded with silver nanoparticles,CS‐AgNPs,using thymus syriacus,wild mint,and rosemary essential oil extracts as reducing and capping agents
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Fadi AL‐Shnani Thanaa Al‐Haddad Francois Karabet Abdul Wahab Allaf 《Journal of Physical Organic Chemistry》2017,30(11)
The present study describes the green method for the preparation of chitosan loaded with silver nanoparticles (CS‐AgNPs) in the presence of 3 different extracted essential oils. The essential oils play dual roles as reductant and capping agents. The reducing power and DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) assay for the 3 essential oils—Thymus syriacus (T), wild mint (M), and rosemary (R)—have been reported. The preparation of CS‐AgNPs was performed by 2 steps. The 3 previously extracted essential oils have been used as reducing and capping agent in the first step, while in the second step, silver nanoparticles were integrated in chitosan. The integration of AgNPs in the structure of chitosan was confirmed by ultraviolet‐visible, Fourier transform infrared spectroscopy, scanning electron microscopy techniques, and energy dispersive X‐ray. Surface plasmon resonance confirmed the formation of CS‐AgNPs with maximum absorbance at λmax between 405 ‐ 410 and 410 ‐ 430 nm for colloidal and films of CS‐AgNPs, respectively. The intensity of bands at 3408 cm?1 in the fourier transform infrared spectroscopy measurements was decreased substantially and shifted slightly to lower frequency (?υ = 43 cm?1). Scanning electron microscopy shows a spherical morphology of AgNPs with size of 62 nm for both colloidal and film samples, and energy dispersive X‐ray analysis shows peaks confirming AgNPs formation. 相似文献
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In this paper, we investigate the accuracy of the Homotopy Analysis Method (HAM) for solving the problem of the spread of a non-fatal disease in a population. The advantage of this method is that it provides a direct scheme for solving the problem, i.e., without the need for linearization, perturbation, massive computation and any transformation. Mathematical modeling of the problem leads to a system of nonlinear ODEs. MATLAB 7 is used to carry out the computations. Graphical results are presented and discussed quantitatively to illustrate the solution. 相似文献
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Liu Z Gu C Chen F Yang D Wu K Chen S Jiang J Zhang Z 《Applied biochemistry and biotechnology》2012,166(3):722-734
Phytochelatin synthase (PCS) is a key enzyme involved in the synthesis of phytochelatins, which are thought to play important
roles in heavy metal detoxification. The sacred lotus (Nelumbo nucifera), one of the most popular ornamental species, has been shown to be a potential phytoremediator of heavy metal polluted water.
However, the phytochelatin synthase gene in N. nucifera has not been identified yet. Here, we report the isolation and function characterization of a N. nucifera homologue of phytochelatin synthase. The sequence obtained shares a high degree of similarity with PCSs from other plant
species and was named as Nelumbo nucifera phytochelatin synthase1 (NnPCS1). By using quantitative RT-PCR, we found that the expression of NnPCS1 in leaves of N. nucifera was dramatically increased in response to Cadmium (Cd) treatment. We further showed that, when exposed to Cd stress, Arabidopsis transgenic plants heterologous expressing NnPCS1 accumulated more Cd when compared with wild type. These results suggest that NnPCS1 involved in the response of N. nucifera to Cd stress and may represent a useful target gene for the phytoremediation of Cd-polluted water. 相似文献