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111.
Joris Van Loco Maureen Moerenhout Hedwig Beernaert 《Accreditation and quality assurance》2003,8(2):61-67
A GLP study can be performed at more than one site. This is called a multi-site study. Although, the study is performed at
different sites, it is still one study and must completely comply with the GLP principles. The fact that different activities
are conducted at different sites implies that the planning, the organization and the communication are crucial for the success
of the study. This means that all the staff involved should know their responsibilities and should have the knowledge and
skills to realize all the phases of the study according to the GLP principles. To achieve a well managed multi-site study,
several strategies for setting up such a study can be followed. This paper focuses on the responsibilities, communication,
and collaboration of the personnel, which are involved in a multi-site study. Several case studies are highlighted, and we
concluded that the basic communication triangle in a single-site GLP study between test facility management, study director,
and the quality assurance unit should be extended to the communication among test facility and test site management, study
director, principle investigator(s), and the quality assurance units at the test sites.
Introduction
Received: 14 August 2002 Accepted: 26 November 2002 相似文献
112.
A microwave-assisted click chemistry synthesis of 1,4-disubstituted 1,2,3-triazoles via a copper(I)-catalyzed three-component reaction 总被引:4,自引:0,他引:4
A microwave-assisted three-component reaction was used to prepare a series of 1,4-disubstituted-1,2,3-triazoles from corresponding alkyl halides, sodium azide, and alkynes. This procedure eliminates the need to handle organic azides, as they are generated in situ, making this already powerful click process even more user-friendly and safe. 相似文献
113.
13CT1 relaxation times for the different carbons of the sodium dodecyl sulphate chain in micellar systems have been measured, using Gd3+ as a paramagnetic relaxation reagent. The fluorescence decay of ω-(-naphthyl) dodecanoic acid, solubflized in the sodium dodecyl sulphate micelles was obtained in the presence of various amounts of counterion quencher Both series of experiments point to the occurrence of chain folding and to the fact that the terminal group can approach the Stern region of the micelle. 相似文献
114.
Gas-phase derivatization of [C3H5]+ ions using tandem mass spectrometry methods A13C labelling study
Nguyen Kieu My Marita Schilling Helmut Schwarz 《Journal of mass spectrometry : JMS》1987,22(5):254-258
The study of specifically 13C-labelled precursors sheds further light on the gas-phase chemistry of allyl and 2-propenyl cations. It is demonstrated that both species are formed from allyl and 2-propenyl bromide upon 70 eV electron impact ionization without skeletal reorganization. Gas-phase derivatization of the [C3 H5]+ ions with benzene facilitates, as suggested and observed earlier, the distinction of the two isomers using collision-induced dissociation of the Wheland complexes (or isomers thereof). The 13C labelling data clearly demonstrate that 64% of allyl cations survive the derivatization while 36% isomerize to 2-phenylpropyl cations; the latter are also formed via the reaction of 2-propenyl cation with benzene, protonation of α-methylstyrene and water loss from protonated 2-phenyl-2-propanol, respectively. Unimolecular loss of C2H4 from protonated allylbenzene proceeds via two competing reaction channels: one involves heterolysis of 1-phenylpropyl cations (~30%); the major pathway (~70%), however, involves decomposition via propylene benzenium ions. 相似文献
115.
Mass spectrometric analysis of ceramide perturbations in brain and fibroblasts of mice and human patients with peroxisomal disorders 总被引:2,自引:0,他引:2
Pettus BJ Baes M Busman M Hannun YA Van Veldhoven PP 《Rapid communications in mass spectrometry : RCM》2004,18(14):1569-1574
In this study, the levels and composition of ceramides in brains of newborn mice lacking peroxisomes (Pex5-/-, Zellweger mice) were analyzed using normal-phase high-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (HPLC/APCI-MS). Total ceramide compositions were found to be comparable to that of control animals. However, a minor ceramide species, containing hexacosanoic/hexacosenoic acid as the amide fatty acid, was 9-fold increased. Also, in the sphingomyelin-derived ceramides this species was elevated. Subsequent analysis of extracts from fibroblasts of Pex5-/- mice and mice with a defective peroxisomal beta-oxidation (lacking D-specific multifunctional protein 2 (MFP2)), revealed, again, a similar rise in this particular ceramide. Further, this ceramide was elevated in human X-ALD fibroblasts as well. Whether C26:1/0-ceramide is linked to some of the pathology seen in Zellweger syndrome remains to be investigated. However, an increase in this sphingolipid can be considered as a diagnostic criterion for diseases caused by defects in peroxisome biogenesis or peroxisomal beta-oxidation. 相似文献
116.
Pham-Tran NN Bouchoux G Delaere D Nguyen MT 《The journal of physical chemistry. A》2005,109(12):2957-2963
We have investigated the basicity of phosphinine (C5H5P, phosphabenzene) in reevaluating its proton affinity (PA) and gas-phase basicity (GB) and the pK(a) value of its protonated form. As a necessary step, we have first determined its gas-phase proton affinity. Using both mass spectrometric and quantum chemical methods, we have obtained the values PA(C5H5P) = 195.8 +/- 1.0 kcal mol(-1) and GB(298)(C5H5P) = 188.1 +/- 1.0 kcal mol(-1), in good agreement with previous results. We then derived a value of pK(a)(C5H6P+) = -16.1 +/- 1.0 in aqueous solution using three different approaches: the latter markedly differs from the currently available value of -10. The reason for such a discrepancy in the pK(a) of protonated phosphinine in solution is discussed. In the theoretical determination of PAs, evaluation of the basis set superposition error (BSSE) showed that this effect is quite small, being 0.1-0.2 kcal mol(-1) for phosphinine, when a density functional theory (DFT) method in conjunction with a large basis set were used. 相似文献
117.
A novel generally applicable synthesis of coumarins from phenolic substrates utilizing ring-closing metathesis is described. This sequence involves O-allylation of phenols followed by ortho-Claisen rearrangement, subsequent based-induced isomerization affording 2-(1-propenyl)phenols, acylation with acryloyl chloride, and finally ring-closing metathesis (RCM) with Grubbs’ second generation catalyst. 相似文献
118.
Perfluoromethyl Element Ligands. XXIX. Preparation and Spectroscopic Investigation of M(CO)4L2 Complexes (M ? Cr, Mo, W; L ? Me2PSMe, Me2PSeMe, (CF3)2PSMe, (CF3)2PSMe) The complexes M(CO)4L2 (see Inhaltsübersicht) have been prepared by the reaction of tetracarbonyl norbornadiene metal compounds M(CO)4NBD with L at room temperature or 35°C, respectively. The cis-complexes formed in the first step undergo rearrangement to trans-isomers at higher temperatures. New compounds have been characterized by analytical and spectroscopic (IR, NMR, MS) methods. 相似文献
119.
120.
H. L. L. M. Van Leengoed N. van der Veen A. A. C. Versteeg R. Ouellet J. E. van Lier W. M. Star 《Photochemistry and photobiology》1993,58(4):575-580
Six sulfonated metallophthalocyanines, chelated with either aluminum or zinc and sulfonated to different degrees, were studied in vivo for their photodynamic activity in a rat skin-fold chamber model. The chamber, located on the back of female WAG/Rij rats, contained a syngeneic mammary carcinoma implanted into a layer of subcutaneous tissue. Twenty-four hours after intravenous administration of 2.5 μmol/kg of one of the dyes, the chambers received a treatment light dose of 600 J/cm2 with monochromatic light of 675 nm at a power density of 100 mW/ cm2. During light delivery and up to a period of 7 days after treatment, vascular effects of tumor and normal tissue were scored. Tumor cell viability was determined by histology and by reimplantation of the chamber contents into the skin of the same animal, either 2 h after treatment or after the 7 day observation period. Vascular effects of both tumor and subcutaneous tissue were strongest with dyes with the lowest degree of sulfonation and decreased with increasing degree of sulfonation. Tumor regrowth did not occur with aluminum phthalocyanine mono- and disulfonate and with zinc phthalocyanine monosulfonate. With the protocol that was used, complete necrosis without recovery was only observed when reimplantation took place at the end of the 7 day follow-up period. Reimplantation 2 h after treatment always resulted in tumor regrowth. At this interval, the presence of viable tumor cells was confirmed histologically. In general tumor tissue vasculature was more susceptible to photodynamic damage than vasculature of the normal tissue. The effect on the circulation of both tumor and normal tissue increased with decreasing degree of sulfonation. Based on this study, the photodynamic effects using the six sulfonated metallophthalocyanines on the vasculature can be ranked from high to low as: AlPcS2= ZnPcS1 > AIPcS1 > AIPcS4 > ZnPcS2 > ZnPcS4. 相似文献