排序方式: 共有47条查询结果,搜索用时 0 毫秒
1.
2.
3.
C T Elliott G A Baxter S A Hewitt C J Arts M van Baak K E Hellen?s A Johannson 《The Analyst》1998,123(12):2469-2473
The drug salbutamol (SBL) is a beta-agonist that may be used illegally as an animal growth promoter. SBL is also a good example of a drug which is excreted in the form of glucuronides and sulfates. Such metabolites cause complexities in analysing for the presence of drug residues. In the majority of cases a process of deconjugation and sample clean-up is required prior to analysis. This is both time consuming and causes some loss of accuracy. In this study, the urine of calves treated with SBL orally for 3 d was collected during and after medication. Samples were assayed before and after hydrolysis by two different methods, radioimmunoassay (RIA) and a newly developed biosensor immunoassay (BIA). Some samples were also analysed by GC-MS. The results clearly showed that both screening assays (RIA and BIA) found high concentrations of SBL residues throughout the study. This was especially true in the BIA method. It was also demonstrated that urine sample analysis without the need for deconjugation or clean-up could be achieved. Results obtained by GC-MS tended to be an order of magnitude lower than the corresponding screening test results. This work showed that biosensor based veterinary drug residue testing procedures can be developed which can generate results in real time without the need for time consuming sample preparation. 相似文献
4.
5.
The synthesis of three bridgehead homocuneanes acetates viz 1-bromopentacyclo [4.3.0.02.4.03.8.05.7]nonan-9-one ethylene ketal 4-acetate (10), 1-bromopentacyclo[4.3.0.02.4.03.8.05.7]nonane 4-acctate (22) and pentacyclo[4.3.0.02.4.03.8.05.7]nonane-9-one ethylene ketal 4-acetate (31) is described, starting from the readely available homocubane carboxylic acid (4). The base and acid catalyzed homoketonization reaction of these acetates has been studied. Under basic conditions the acetates (10, 22 and 31) are converted into tettacyclo[4.3.0.02.4.03.8]nonane derivatives by a cyclopropanol ring cleavage. This homoketonization reaction is a stereospecific process proceeding with retention of configuration. The effect of cage strain on the stereochemistry of base induced homoketonization of bridgehead cage alcohols is discussed.The acid catalyzed homoketonization of acetate (10) was also found to occur exclusively with retention of configuration. 相似文献
6.
Karwal Saurabh Verheijen Marcel A. Arts Karsten Faraz Tahsin Kessels Wilhelmus M. M. Creatore Mariadriana 《Plasma Chemistry and Plasma Processing》2020,40(3):697-712
Plasma Chemistry and Plasma Processing - In this work, we report on the atomic layer deposition (ALD) of HfNx thin films by employing CpHf(NMe2)3 as the Hf(IV) precursor and Ar–H2 plasma in... 相似文献
7.
Hong She Wang Wei Xing Zhao 《中国化学快报》2011,22(8):911-914
An efficient magnesium bistrifluoromethanesulfonimide[Mg(NTf_2)_2]catalyzed hydroalkylation of aromatic olefins with 1,3- diketones under solvent-free conditions has been developed.The reactions proceed smoothly to give the desired products in good yields in short reaction times. 相似文献
8.
Stephen MT Hoke Gaoyang Liang A Irina Mutiu Julie Genereaux Christopher J Brandl 《BMC biochemistry》2007,8(1):16
Background
Spt7 is an integral component of the multi-subunit SAGA complex that is required for the expression of ~10% of yeast genes. Two forms of Spt7 have been identified, the second of which is truncated at its C-terminus and found in the SAGA-like (SLIK) complex. 相似文献9.
He JiweiDept.of Math. Zhejiang Univ. Hangzhou China. Dept.of Math. Shaoxing College of Arts Science Shaoxing China. 《高校应用数学学报(英文版)》2004,(1)
§ 0 IntroductionA∞ - algebras were first introduced and applied by Stasheff in [12 ,13].Recently,theyappeared in both mathematics and mathematical physics[1 ,5— 8,1 0 ] .An A∞ - algebra is a Z-graded vector space over a fixed field k with a sequence of graded maps mn∶ A n→ A ofdegree n- 2 (n≥ 1) satisfying certain axioms (see [5 ,6 ,12 ,13]) .In this paper,we focusour attentions on,as we call,the minimal A∞ - algebras,which are usual A∞ - algebrasdefined in [5 ,6 ,12 ,13]with m1 =… 相似文献
10.