Search

Your search keyword '"C.S. French"' showing total 5 results
Start Over Author "C.S. French" Topic chemistry
5 results on '"C.S. French"'

1. Determining the Specific Alpha Activity of Thick Sources Using a Large-area Zinc Sulfide Detector

Author

G. A. Falo, G.E. Chabot, K.W. Skrable, K. A. Phoenix, M. Jo, and C.S. French

Subjects
Range (particle radiation), Epidemiology, Chemistry, business.industry, Health, Toxicology and Mutagenesis, Instrumentation, Detector, Alpha particle, Sulfides, Alpha Particles, Zinc sulfide, Ionizing radiation, Zinc, chemistry.chemical_compound, Optics, Sampling (signal processing), Zinc Compounds, Radiology, Nuclear Medicine and imaging, Radiometry, business, Absorption (electromagnetic radiation)
Abstract

A simple method using a large-area zinc sulfide detector to determine the total specific alpha activity of thick sources is presented. A previous paper shows how the linear absorption properties of weightless alpha sources can be applied to thick sources placed in direct contact with a varying thickness of window material. A quadratic relationship between the detector response and absorber thickness was derived for sources whose thickness exceeds the range of the alpha particle. The coefficient of the linear term in the quadratic expression is used to calculate the total specific alpha activity of a source in contact with the window of the detector. This relationship is tested by obtaining alpha absorption data from solid sources of known specific alpha activity, fitting the data to the theoretical relationship and comparing the results to the known activities.

Published
1993
Full Text
View/download PDF

2. Determination of junction depths for phosphorous diffused in silicon

Author

C.S. French, D.E. Kardes, D.P. Belman, and R.W. Hendricks

Subjects
Secondary ion mass spectrometry, Materials science, Dopant, Silicon, chemistry, Electrical resistivity and conductivity, Doping, Analytical chemistry, chemistry.chemical_element, Wafer, Diffusion (business), Sheet resistance
Abstract

P was diffused into p-type Si wafers containing B at 1100/spl deg/C for six different times using a solid state source and a standard pre-deposition process. Secondary ion mass spectrometry (SIMS) provided profiles of dopant concentration versus wafer depth from which both the surface concentration and the junction depths for the six wafers were determined. These profiles were fitted acceptably well by the constant supply model of diffusion in the dilute "tail region" identified by Fair, although indications of concentration-dependent diffusion were observed. Two independent determinations of the sheet resistivity of each sample were made. The results confirmed the correct operation of our custom-built sheet resistivity system. The resulting data allow us to predict the junction depth within 0.2 /spl mu/m over a range from 1.0 to 2.0 /spl mu/m. A plot of the dopant surface concentration, N/sub 0/, versus the product of the sheet resistivity and the junction depth, R/sub s/x/sub j/, agrees well with data from the Irvin plot.

Published
2002
Full Text
View/download PDF

5. Nicotine inhibits the VTA-to-amygdala dopamine pathway to promote anxiety

Author

Stéphanie Pons, Fabio Marti, Clément Solié, Jean-François Fiancette, Véronique Deroche-Gamonet, Joachim Jehl, Deniz Dalkara, Alexandre Mourot, Jean-Pierre Hardelin, Steve Didienne, Tinaïg Le Borgne, Stefania Tolu, Lauren M. Reynolds, B. Hannesse, Ines Centeno, Uwe Maskos, Sébastien Valverde, Maxime Come, Philippe Faure, Claire Nguyen, Sarah Mondoloni, Romain Durand-de Cuttoli, Laboratoire Plasticité du Cerveau Brain Plasticity (UMR 8249) (PdC), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Neurosciences Paris Seine (NPS), Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Biologie Paris Seine (IBPS), Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Physiopathologie de la Plasticité Neuronale (Neurocentre Magendie - U1215 Inserm), Université de Bordeaux (UB)-Institut François Magendie-Institut National de la Santé et de la Recherche Médicale (INSERM), Neurobiologie intégrative des Systèmes cholinergiques / Integrative Neurobiology of Cholinergic Systems (NISC), Sorbonne Université (SU)-Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Institut de la Vision, Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM), This work was supported by Centre national de la recherche scientifique (CNRS, UMR 8246), Institut national de la santé et de la recherche médicale (Inserm, U1130), Fondation pour la recherche médicale (FRM, DEQ2013326488 to P.F., FDT201904008060 to S.M., ECO201806006688 to J.J., and SPF202005011922 to C.S.), French National Cancer Institute grants TABAC-16-022 and TABAC-19-020 (to P.F.), French state funds managed by Agence Nationale de la Recherche (ANR-16 Nicostress to P.F., ANR-19 Vampire to F.M.), and LabEx Bio-Psy (to P.F. and a doctoral fellowship to C.N.). L.M.R. was supported by a National Institute on Drug Abuse (NIDA)-Inserm Postdoctoral Drug Abuse Research Fellowship. P.F. and U.M. are members of LabEx Bio-Psy., ANR-16-CE16-0020,nicostress,Réseaux neuronaux sous-tendant l'intéraction entre stress et nicotine dans le cadre des troubles psychiatriques(2016), ANR-19-CE16-0001,VAmPiRe,Effets opposés de la nicotine sur des neurones dopaminergiques distincts : un rôle spécifique de la voie VTA-Amygdala dans le renforcement(2019), ANR-11-LABX-0035,BIOPSY,Laboratoire de Psychiatrie Biologique(2011), Moheb, Tara, Réseaux neuronaux sous-tendant l'intéraction entre stress et nicotine dans le cadre des troubles psychiatriques - - nicostress2016 - ANR-16-CE16-0020 - AAPG2016 - VALID, Effets opposés de la nicotine sur des neurones dopaminergiques distincts : un rôle spécifique de la voie VTA-Amygdala dans le renforcement - - VAmPiRe2019 - ANR-19-CE16-0001 - AAPG2019 - VALID, Laboratoire de Psychiatrie Biologique - - BIOPSY2011 - ANR-11-LABX-0035 - LABX - VALID, Neuroscience Paris Seine (NPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Neurocentre Magendie : Physiopathologie de la Plasticité Neuronale (U1215 Inserm - UB), Institut Pasteur [Paris] (IP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, nucleus accumbens, Dopamine, Anxiety, Receptors, Nicotinic, dopamine circuits, MESH: Nicotine, Nicotine, Mice, [SCCO]Cognitive science, 0302 clinical medicine, MESH: Amygdala, Neural Pathways, MESH: Dopaminergic Neurons, MESH: Animals, Nicotinic Agonists, 0303 health sciences, Chemistry, General Neuroscience, musculoskeletal, neural, and ocular physiology, amygdala, Ventral tegmental area, Nicotinic agonist, medicine.anatomical_structure, MESH: Receptors, Nicotinic, addiction, MESH: Nucleus Accumbens, Reinforcement, Psychology, psychological phenomena and processes, medicine.drug, ventral tegmental area, MESH: Dopamine, Nucleus accumbens, Optogenetics, Amygdala, 03 medical and health sciences, mental disorders, MESH: Nicotinic Agonists, medicine, Animals, optogenetics, MESH: Mice, 030304 developmental biology, MESH: Anxiety, Dopaminergic Neurons, MESH: Neural Pathways, [SCCO] Cognitive science, MESH: Male, Anxiogenic, nervous system, juxtacellular recordings, MESH: Ventral Tegmental Area, nicotinic acetylcholine receptors, Neuroscience, MESH: Reinforcement, Psychology, 030217 neurology & neurosurgery, nicotine
Abstract

International audience; Nicotine stimulates dopamine (DA) neurons of the ventral tegmental area (VTA) to establish and maintain reinforcement. Nicotine also induces anxiety through an as yet unknown circuitry. We found that nicotine injection drives opposite functional responses of two distinct populations of VTA DA neurons with anatomically segregated projections: it activates neurons that project to the nucleus accumbens (NAc), whereas it inhibits neurons that project to the amygdala nuclei (Amg). We further show that nicotine mediates anxiety-like behavior by acting on β2-subunit-containing nicotinic acetylcholine receptors of the VTA. Finally, using optogenetics, we bidirectionally manipulate the VTA-NAc and VTA-Amg pathways to dissociate their contributions to anxiety-like behavior. We show that inhibition of VTA-Amg DA neurons mediates anxiety-like behavior, while their activation prevents the anxiogenic effects of nicotine. These distinct subpopulations of VTA DA neurons with opposite responses to nicotine may differentially drive the anxiogenic and the reinforcing effects of nicotine.

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results