Multi-site

Reeves L W and Shaw K N 1970 Nuclear magnetic resonance studies of multi-site chemical exchange. I. Matrix formulation of the Bloch equations Can. J. Chem. 48 3641-53... 

If T is symmetric then v = and only one eigenvector calculation is required. Multi-site and longer-ranged correlators are obtained by appropriate bond counting, without the explicit introduction of the corresponding interactions into the Hamiltonian, however. 

Additional applications of the transfer matrix method to adsorption and desorption kinetics deal with other molecules on low index metal surfaces [40-46], multilayers [47-49], multi-site stepped surfaces [50], and co-adsorbates [51-55]. A similar approach has been used to study electrochemical systems. 

In this review article we have tried to show that an analytical approach to the thermodynamics and the kinetics of adsorbates is not restricted to simple systems but can deal with rather complicated situations in a systematic approach, such as multi-site and multi-component systems with or without precursor-mediated adsorption and surface reconstruction, including multi-layers/subsurface species. This approach automatically ensures that such fundamental principles as detailed balance are implemented properly. 

Figure 1 Metallocene-single-site versus Ziegler-Natta multi-site catalysts. (From Ref. 34. Reprinted with permission from Chemical Engineering, McGraw-Hill, Inc., New York, 1993.)...

Subjects up to 3000 drawn from broad patient base multi-site, multi-group Duration 3-5 years or longer... 

Anton RF, Pettinati H, Zweben A, et al A multi-site dose ranging study of nalmefene in the treatment of alcohol dependence. J Clin Psychopharmacol 24 421 28, 2004 Aragon CM, Stotland LM, Amit Z Studies on ethanol-brain catalase interaction evidence for central ethanol oxidation. Alcohol Clin Exp Res 15 165-169, 1991 Arizzi MN, Correa M, Betz AJ, et al Behavioral effects of intraventricular injections of low doses of ethanol, acetaldehyde, and acetate in rats studies with low and high rate operant schedules. Behav Brain Res 147 203—210, 2003 Azrin NH, Sisson RW, Meyers R, et al Alcoholism treatment by disulfiram and community reinforcement therapy. J Behav Ther Exp Psychiatry 13 105—112, 1982 Babor TF, Kranzler HR, Lauerman RL Social drinking as a health and psychosocial risk factor Anstie s limit revisited, in Recent Developments in Alcoholism, Vol 5. Edited by Galanter M. New York, Plenum, 1987, pp 373 02... 

Anton RF, Pettinati H, Zwehen A, et al A multi-site dose ranging smdy of nalmefene in the treatment of alcohol dependence. J Clin Psychopharmacol 24 421 28, 2004 Azrin NH Improvements in the community reinforcement approach to alcoholism. Behav Res Ther 14 339-348, 1976... 

Homopolymers made with multi-site catalysts tend to have composite tacticities, with each site generating a distinctive set of intensities in accordance with certain reaction probabilities. Such polymers can be regarded as in-situ blends of several components, each one bearing a different tacticity. Fractionation would then separate the polymer into different fractions, and the tacticities of each fraction would reflect the different proportions of the various conqponents. The MMR data on the fractions potentially contain Information on the weight percent of each component as well as the reaction probabilities. 

In order to test higher-order or multi-site models, it is preferable to study HMR data of polymer fractions. In this work, we shall use the pairwise HMR/fractions data to fit to multi-site models. This Is carried out in the same way as in the pairwise fraction on the tactlcity data. We can either use the two-state B/B model, or even three-state B/B/B model If applicable. The comonomer sequence intensity data for the two fractions are entered Into the computer. A total of 12 entries are Involved (6 for each fraction). The equations for the three-state copolymer... 

Computer simulations have been useful for validating a kinetic model that Is not easily tested. The model was equally capable of describing multi-site polymerizations which can undergo either first or second order deactivation. The model parameters provided reasonably accurate kinetic information about the Initial active site distribution. Simulation results were also used as aids for Interpretation of experimental data with encouraging results. 

All phases of a multi-site regulatory study should be carried out in facilities that are members of the UK or a relevant national GLP compliance program. Pre-study test site inspections may be conducted if considered necessary. If an organization is considering using a particular test site, a copy of the test facility s current GLP certificate should be obtained and included in the QA multi-site file. 

If the test facility claims to be GLP-compliant but is located in a country where there is no authorised body responsible for GLP monitoring, i.e., a national GLP compliance program, the Study Director needs to be assured that the facility (including the archive, if used) does operate in compliance with GLP principles. This can be achieved by conducting a pre-study QA test site inspection or by a review of documentary evidence, e.g., notice of adverse findings and subsequent responses, or Establishment Inspection reports. The Study Director should ideally discuss the above with QA personnel and send copies of any documentary evidence used to the Quality Assurance Unit (QAU) for inclusion in the QA multi-site study file. 

In some instances, phases of a multi-site study may have to be conducted in a noncompliant facility, e.g., if there are no GLP-compliant facilities that can conduct the work. In the UK there are two options for dealing with this. 

Include a disclaimer or deviation in the Study Director GLP compliance statement. The disclaimer route can be used for a phase of a multi-site study but should generally not be used if the work in question is a critical phase, e.g., application. The remainder of the study must be conducted in accordance with the principles of GLP. This route may not be acceptable to overseas regulators and should be avoided if possible. 

The Study Director/Principal Investigator should ideally discuss all multi-site studies with QA personnel prior to study initiation (or prior to the issue of the protocol amendment if work is not detailed in the protocol). When acting as Study Director, a copy of the current GLP certificates should be requested from sub-contracted facilities and should be retained in QA. 

The length of data storage must be noted in the Study Plan (as a mle a minimum of 10 years for most of the countries within the EU). This, however, can differ between different countries within the EU. Where multi-site smdies are conducted, me location of study raw data for each site must be specified. One preference is to have all original... 

Some Multi-Site Ligands Containing Nitrogen Donor Sites and Metal Complexes Derived from Them... 

Published only some of the results from multi-site studies... 

There has to be a documented set of procedures for replacing a Study Director should that become necessary. In addition, for multi-site studies there has to be appointed a Principal Investigator for each site. Principal Investigators have to have the appropriate qualifications and experience to manage the delegated part of the study. 

Kulik, D. A., 2002, Gibbs energy minimization approach to model sorption equilibria at the mineral-water interface Thermodynamic relations for multi-site-surface complexation. American Journal of Science 302,227-279. ... 

Shah, N. (1998) Single- and Multi-Site Planning and Scheduling Current Status and Future Challenges. Proceedings of the 3rd Conference Foundations of Computer-Aided Process Operations, CACHE, Michigan, pp. 75-90. 

Possible solution enrichment strategies in which 50 or so likely candidates are collected and paired with 250 unlikely candidates. Another option would be to establish multi-site trials. 

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