排序方式: 共有36条查询结果,搜索用时 31 毫秒
1.
Jose Castro‐Perez Nathan Hatcher Nana Kofi Karikari Sheng‐Ping Wang Vivienne Mendoza Henry Shion Alan Millar John Shockcor Mark Towers David McLaren Vinit Shah Stephen Previs Karen Akinsanya Michele Cleary Thomas P. Roddy Douglas G. Johns 《Rapid communications in mass spectrometry : RCM》2014,28(22):2471-2479
2.
Vinit K. MittalSantanu Bera S.V. NarasimhanS. Velmurugan 《Applied Surface Science》2011,258(4):1525-1530
Sorption of Sb(III) on carbon steel surface in aqueous medium (pH 2.8) in presence of different oxyanions like molybdate and selenite has been studied. It is observed that the presence of molybdate or selenite in solution reduced Sb(III) adsorption and surface precipitation to a great extent. The solution at different stages of the adsorption experiment has been analyzed by inductively coupled plasma-atomic emission spectroscopy technique. X-ray diffraction and X-ray photoelectron spectroscopy (XPS) techniques have been used to characterize the precipitate layer and the adsorbed layer. A detailed analysis of the XPS data reveals the mechanism involved in the two cases. 相似文献
3.
A right module $M$ over an associative ring $R$ with unity is a $QTAG$-module if every finitely generated submodule of any homomorphic image of $M$ is a direct sum of uniserial modules. This article considers the closure of $h$-pure-$S$-high submodules of $QTAG$-modules. Here, we determine all submodules $S$ of a $QTAG$-module $M$ such that each closure of $h$-pure-$S$-high submodule of $M$ is $h$-pure-$\overline{S}$-high in $\overline{M}$. A few results of this theme give a comparison of some elementary properties of $h$-pure-$S$-high and $S$-high submodules. 相似文献
4.
Castro-Perez J Roddy TP Nibbering NM Shah V McLaren DG Previs S Attygalle AB Herath K Chen Z Wang SP Mitnaul L Hubbard BK Vreeken RJ Johns DG Hankemeier T 《Journal of the American Society for Mass Spectrometry》2011,22(9):1552-1567
A high content molecular fragmentation for the analysis of phosphatidylcholines (PC) was achieved utilizing a two-stage [trap (first generation fragmentation) and transfer (second generation fragmentation)] collision-induced dissociation (CID) in combination with travelling-wave ion mobility spectrometry (TWIMS). The novel aspects of this work reside in the fact that a TWIMS arrangement was used to obtain a high level structural information including location of fatty acyl substituents and double bonds for PCs in plasma, and the presence of alkali metal adduct ions such as [M?+?Li]+ was not required to obtain double bond positions. Elemental compositions for fragment ions were confirmed by accurate mass measurements. A very specific first generation fragment ion m/z 577 (M-phosphoryl choline) from the PC [16:0/18:1 (9Z)] was produced, which by further CID generated acylium ions containing either the fatty acyl 16:0 (C15H31CO+, m/z 239) or 18:1 (9Z) (C17H33CO+, m/z 265) substituent. Subsequent water loss from these acylium ions was key in producing hydrocarbon fragment ions mainly from the α-proximal position of the carbonyl group such as the hydrocarbon ion m/z 67 (+H2C-HC?=?CH-CH?=?CH2). Formation of these ions was of important significance for determining double bonds in the fatty acyl chains. In addition to this, and with the aid of 13C labeled lyso-phosphatidylcholine (LPC) 18:1 (9Z) in the ω-position (methyl) TAP fragmentation produced the ion at m/z 57. And was proven to be derived from the α-proximal (carboxylate) or distant ω-position (methyl) in the LPC. 相似文献
5.
The kinetics of acetone evaporation from films obtained by casting solutions of cellulose diacetate-acetone-water-inorganic additive have been analysed. Three successive regimes of evaporation have been identified. The first two are exponential and end, respectively, at critical times t1 and t2. Casting solution compositions have been determined both at the instant of phase separation (cloud point) and upon complete gelation. Also, the period of evaporation required to produce total film opacification has been measured for certain systems. These measurements have shown that time t1 corresponds to polymer precipitation at the film surface, and that time t2 corresponds to complete gelation of the medium. The results illustrate the effects of film thickness, casting temperature and “swelling” or “gelling” characteristics of the inorganic additive on times t1 and t2. 相似文献
6.
V Kumar T Endoh K Murakami N Sugimoto 《Chemical communications (Cambridge, England)》2012,48(78):9693-9695
Conformational dynamics and observed equilibrium constants for ligand binding of the adenine-specific riboswitch (add-A riboswitch) in the absence of Mg(2+) and presence of various concentrations of poly-ethylene glycol having an average molecular weight of 200 indicated that 54.2 water molecules were released from P2 and P3 stem regions of the add-A riboswitch during conformational transition upon the binding of 2-aminopurine, an analog of the natural ligand adenine. 相似文献
7.
A pentaammineazidocobalt(III) complex, [Co(NH3)5N3](MnO4)2XH2O has been synthesized by an one-pot synthesis method. It was characterized by studies such as infrared (IR) and UV-visible spectroscopy. The single crystal X-ray structure analysis revealed that the title complex crystallizes in space group Cc. The cobalt center is six coordinated with slightly octahedral geometry. The supramolecular architecture is also formed by intermolecular N-H…O (anion and H2O) and Mn-O…O-H hydrogen bonds. The binding property of the cation, [Co(NH3)5N3]2+ with the anion, MnO4– has also been determined (in solution phase) with the help of UV-visible spectroscopic titrations. Further, the genotoxic effects of KMnO4, [Co(NH3)5N3]Cl2 and [Co(NH3)5N3](MnO4)2XH2O were studied using Allium cepa root chromosomal aberration assay and it revealed that the genotoxicity of the newly synthesized complex is 1.97–1.76 fold, which is less compared to KMnO4. The order of genotoxic potential has been observed to be KMnO4 > [Co(NH3)5N3](MnO4)2XH2O > [Co(NH3)5N3]Cl2. 相似文献
8.
Mesoporous Manganese Oxide Catalyzed Aerobic Oxidative Coupling of Anilines To Aromatic Azo Compounds 下载免费PDF全文
Dr. Vinit Sharma Prof. Nancy Ortins Savage Prof. S. Pamir Alpay Prof. Steven L. Suib 《Angewandte Chemie (International ed. in English)》2016,55(6):2171-2175
Herein we introduce an environmentally friendly approach to the synthesis of symmetrical and asymmetrical aromatic azo compounds by using air as the sole oxidant under mild reaction conditions in the presence of cost‐effective and reusable mesoporous manganese oxide materials. 相似文献
9.
The rotational behaviour of CF4 dissolved in liquid argon is derived from the band contour analysis of Raman spectra recorded over the concentration range from 10-2 mole fraction to 1 mole fraction at 85 K. The angular momentum correlation times have been determined with the help of the J-diffusion model and used to apply the rough hard sphere model. A study of the transition dipole-transition dipole (TD-TD) interaction is made using the v 3 mode at 85 K for different concentrations. 相似文献
10.
Esteghlalian Ali R. Srivastava Vinit Gilkes Neil R. Kilburn Douglas G. Warren R. Antony J. Saddler John N. 《Applied biochemistry and biotechnology》2001,91(1-9):575-592
This article provides an overview of various theories proposed during the past five decades to describe the enzymatic hydrolysis
of cellulose highlighting the major shifts that these theories have undergone. It also describes the effect of the cellulose-binding
domain (CBD) of an exoglucanase/xylanase from bacterium Cellulomonas fimi on the enzymatic hydrolysis of Avicel. Pretreatment of Avicel with CBDCex at 4 and 37°C as well as simultaneous addition of CBDCex to the hydrolytic enzyme (Celluclast, Novo, Nordisk) reduced the initial rate of hydrolysis owing to irreversible binding
of CBD proteins to the substrate's binding sites. Nonetheless, near complete hydrolysis was achieved even in the presence
of CBDCex. Protease treatment of both pure and CBDCex-treated Avicel reduced the substrates' hydrolyzability, perhapsowing to proteolysis of the hydrolyzing enzyme (Celluclast)
by the residual Proteinase K remaining in the substrate. Better protocols for comptete removal of CBD proteins from the substrate
need to be developed to investigate the effect of CBD adsorption on cellulose digestibility. 相似文献