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          Foreword 
          (9k)  
          I have been disturbed lately by the number of issues on which people 
          take extreme positions... 
          
           Acetylcholinesterase 
          Inhibitors Are Neither Necessary nor Desirable for Microdialysis Studies 
          of Brain Acetylcholine (329k) 
          Acetylcholine (ACh), one of the major neurotransmitters in brain, has 
          an important role in various types of cognition, including attention 
          and memory. ACh is critical to the neurocognitive dysfunction in Alzheimer’s 
          disease and possibly other psychiatric disorders such as schizophrenia. 
          Furthermore, the development of drugs which increase the availability 
          of brain ACh is a major research goal. Thus, direct measurement of brain 
          ACh release under physiological conditions, using in vivo microdialysis, 
          in laboratory animals is of great importance. Because of the low concentration 
          of ACh, many of the microdialysis studies published to date required 
          Acetylcholinesterase (AChE) inhibitors in the perfusion medium to increase 
          basal ACh. However, the artificially increased concentration exerts 
          a significant influence on the cholinergic system, thereby making interpretation 
          of drug effects problematic. We have recently developed a highly sensitive 
          method of ACh measurement, which requires no AChE inhibitors. Advantages 
          of the new method are discussed.  
          
          Simulation 
          of Cyclic Voltammetry Using Finite Difference Methods (46k) 
          This article discusses the application of finite difference methods 
          to the simulation of cyclic voltammograms with particular reference 
          to the BAS simulation software DigiSim®. 
          
          The 
          Electrochemistry of Thiol Self-Assembled Monolayers (SAMs) on a Hanging 
          Mercury Drop Electrode (HMDE) (71k)  
          The 
          electrochemistry of functionalized self-assembled monolayers on Hg is 
          studied by cyclic voltammetry and AC voltammetry. The results suggest 
          that thiols can be adsorbed either chemically or physically depending 
          on the Hg potential. The transformation between these two states occurs 
          via an oxidation-reduction process. While a multi-layer of short chemisorbed 
          thiols is formed under positive potentials than the oxidation-reduction 
          process, a dense monolayer is self-assembled under more negative potentials. 
           
          
          Ramifications 
          of Pump-Switching Step Gradients for Bioanalytical LC/MS/MS 
          (60k) 
          Two 
          separate isocratic LC pumps were configured to perform fast, step gradients 
          for bioanalytical LC/MS/MS assays, simultaneously reducing analysis time 
          and ion suppression, and improving peak shape. Although the technique 
          offers significant advantages for bioanalytical LC/MS/MS assays, it 
          also presents some practical challenges. A newly designed LC pump, the 
          BAS PM-92, is shown to be ideally suited for pump-switching step gradients. 
          
          Products, 
          In the EC Literature, In the MD Literature, Miscellany (79k) 
          In the EC Literature: Adrian Bott, BAS, discusses papers on a 
          special fullerene derivative, reagentless biosensors and much more. 
            
          In the LC Literature: Bruce Solomon of BAS reviews discussions 
          on use of a dual-mode electrochemical detector to determine 3-nitrotyrosine 
          by high-pressure LC and several other recent papers. 
          In the MD Literature: James Gitzen of BAS looks at articles on: 
          the possible reduction in certain behaviors by mGlu2/3 agonists due 
          to changes in dopaminergic activity; the delivery of ondansetron HCI 
          via transdermal microdialysis probes; and microdialysis to separate 
          inorganic anions for analysis in wastewater clean-up.  
          Miscellany: Upcoming conferences and symposia, faculty vacancies, 
          the new Indiana Instrumentation Institute and a discussion of available 
          tools and services for CNS research. 
           
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