Sample records for kanger tnis pehk
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Kouass Sahbani, S; Cloutier, P; Bass, A D; Hunting, D J; Sanche, L
2015-10-01
Transient negative ions (TNIs) are ubiquitous in electron-molecule scattering at low electron impact energies (0-20 eV) and are particularly effective in damaging large biomolecules. Because ionizing radiation generates mostly 0-20 eV electrons, TNIs are expected to play important roles in cell mutagenesis and death during radiotherapeutic cancer treatment, although this hypothesis has never been directly verified. Here, we measure the efficiency of transforming E. coli bacteria by inserting into the cells, pGEM-3ZfL(-) plasmid DNA that confers resistance to the antibiotic ampicillin. Before transformation, plasmids are irradiated with electrons of specific energies between 0.5 and 18 eV. The loss of transformation efficiency plotted as a function of irradiation energy reveals TNIs at 5.5 and 9.5 eV, corresponding to similar states observed in the yields of DNA double strand breaks. We show that TNIs are detectable in the electron-energy dependence of a biological process and can decrease cell viability.
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The use of neutrons for the detection of explosives in Civil Security Applications
NASA Astrophysics Data System (ADS)
Pesente, S.; Fabris, D.; Lunardon, M.; Moretto, S.; Nebbia, G.; Viesti, G.
2007-02-01
The search for hidden explosives has been simulated in laboratory conditions by using our Tagged Neutron Inspection System (TNIS). Applications of the TNIS concept to Civil Security problems are discussed in the light of our projects for cargo container inspections. Moreover, neutron attenuation and scattering can be used to search in real time for large quantity of explosive hidden in vehicles.
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Detection of hidden explosives by using tagged neutron beams: Status and perspectives
NASA Astrophysics Data System (ADS)
Viesti, Giuseppe; Pesente, Silvia; Nebbia, Giancarlo; Lunardon, Marcello; Sudac, Davorin; Nađ, Karlo; Blagus, Sasha; Valković, Vladivoj
2005-12-01
Non-destructive inspections have been simulated in laboratory conditions by using our tagged neutron inspection system (TNIS), using YAP:Ce scintillators to tag the neutron beam and an array of BaF2 crystals to detect the γ-rays. The system has been operated up to 2 × 108 neutron/s. Further developments of the TNIS concept are discussed in the light of our current projects for cargo container inspections.
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Development of the EURITRACK tagged neutron inspection system
NASA Astrophysics Data System (ADS)
Perot, B.; Carasco, C.; Bernard, S.; Mariani, A.; Szabo, J.-L.; Mercier, E.; Sannie, G.; Viesti, G.; Nebbia, G.; Pesente, S.; Lunardon, M.; Moretto, S.; Fabris, D.; Zenoni, A.; Bonomi, G.; Donzella, A.; Fontana, A.; Boghen, G.; Valkovic, V.; Sudac, D.; Moszynski, M.; Batsch, T.; Gierlik, M.; Woski, D.; Klamra, W.; Isaksson, P.; Le Tourneur, P.; Lhuissier, M.; Colonna, A.; Tintori, C.; Peerani, P.; Sequeira, V.; Salvato, M.
2007-08-01
The EURopean Illicit TRAfficing Countermeasures Kit (EURITRACK) project is part of the 6th European Union Framework Program. It aims at developing a Tagged Neutron Inspection System (TNIS) to detect illicit materials, such as explosives and narcotics, in cargo containers. Fast neutron induced reactions produce specific gamma-rays used to determine the chemical composition of the inspected material. The associated particle technique is employed to precisely locate the interaction points of the neutrons. A new deuterium-tritium neutron generator has been developed, including a pixelized alpha particle detector. The TNIS also comprises high-efficiency fast neutron and gamma-ray detectors, a dedicated front-end electronics and an integrated software to entirely drive the system and automatically process the data. Most components have been integrated during last months at Institute Ruder Boskovic, in Zagreb, Croatia. An overview of the TNIS and of its preliminary performances is presented.
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Nerve-responsive troponin I slow promoter does not respond to unloading
NASA Technical Reports Server (NTRS)
Criswell, D. S.; Hodgson, V. R.; Hardeman, E. C.; Booth, F. W.
1998-01-01
We examined the regulation of the troponin I slow (TnIs) promoter during skeletal muscle unloading-induced protein isoform transition, by using a transgenic mouse line harboring the -4,200 to +12 base pairs region of the human TnIs promoter. Eighteen female transgenic mice ( approximately 30 g body mass) were randomly divided into two groups: weight-bearing (WB) controls (n = 9) and hindlimb unloaded (HU; n = 9). The HU mice were tail suspended for 7 days. Body mass was unchanged in the WB group but was reduced (-6%; P < 0.05) after the HU treatment. Absolute soleus muscle mass (-25%) and soleus mass relative to body mass (-16%) were both lower (P < 0.05) in the HU group compared with the WB mice. Northern blot analyses indicate that 7 days of HU result in a 64% decrease (P < 0.05) in the abundance of endogenous TnIs mRNA (microg/mg muscle) in the mouse soleus. Furthermore, there is a trend for the abundance of the fast troponin I mRNA to be increased (+34%). Analysis of transgenic chloramphenicol acetyltransferase activity in the soleus muscle revealed no difference (P > 0.05) between WB and HU groups. We conclude that additional elements are necessary for the TnIs gene to respond to an unloading-induced, slow-to-fast isoform transition stimulus.
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NASA Astrophysics Data System (ADS)
Fontana, Cristiano Lino; Carnera, Alberto; Lunardon, Marcello; Pino, Felix; Sada, Cinzia; Soramel, Francesca; Stevanato, Luca; Nebbia, Giancarlo; Carasco, Cédric; Perot, Bertrand; Sardet, Alix; Sannie, Guillaume; Iovene, Alessandro; Tintori, Carlo; Grodzicki, Krystian; Moszyński, Marek; Sibczyński, Paweł; Swiderski, Lukasz; Moretto, Sandra
The European project entitled ;effective Container inspection at BORDer control points; (C-BORD) focuses on the development and in-situ tests of a comprehensive cost-effective solution for the generalized Non-Intrusive Inspection (NII) of containers and large-volume freight at the European Union (EU) border. It copes with a large range of targets, including explosives, chemical warfare agents, illicit drugs, tobacco and Special Nuclear Materials. Within the C-BORD project, a new generation of Tagged Neutron Inspection System (TNIS) for cargo containers is foreseen. Unlike its predecessors, this system would be the first Rapidly Relocatable TNIS (RRTNIS). It will be a second-line defense system, to be used on sealed containers in order to detect explosives, illicit drugs and chemical agents in a suspect voxel (elementary volume unit). We report on the status of the RRTNIS system, in particular the overall design, the characterization of the large-volume NaI(Tl) gamma detectors, the digital analysis of the time measurements and the Data Acquisition System (DAQ).
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Ring-breaking electron attachment to uracil: following bond dissociations via evolving resonances.
Gianturco, Franco A; Sebastianelli, F; Lucchese, R R; Baccarelli, I; Sanna, N
2008-05-07
Calculations are carried out at various distinct energies to obtain both elastic cross sections and S-matrix resonance indicators (poles) from a quantum treatment of the electron scattering from gas-phase uracil. The low-energy region confirms the presence of pi(*) resonances as revealed by earlier calculations and experiments which are compared with the present findings. They turn out to be little affected by bond deformation, while the transient negative ions (TNIs) associated with sigma(*) resonances in the higher energy region ( approximately 8 eV) indeed show that ring deformations which allow vibrational redistribution of the excess electron energy into the molecular target strongly affect these shape resonances: They therefore evolve along different dissociative pathways and stabilize different fragment anions. The calculations further show that the occurrence of conical intersections between sigma(*) and pi(*)-type potential energy surfaces (real parts) is a very likely mechanism responsible for energy transfers between different TNIs. The excess electron wavefunctions for such scattering states, once mapped over the molecular space, provide nanoscopic reasons for the selective breaking of different bonds in the ring region.
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The Road from LaPalma. Analysis of the Potential for a Negotiated Solution in El Salvador.
1985-09-01
CLASSIFICATION OF THIS PAGE (When Data gntered) UNCLASSIFIED SECURITY CLASSIFICATION OF TNIS PAG hm "M. ft". and cultural bases of bargaining powers in El Salvador...potential gains and costs of continued conflict. This thesis is a study of the historical and cultural bases of bargaining powers in El Salvador, and...of government intervention. Several contending candidates, including two fellow officers, had been disqualified. Government influence over the media
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Distributed Computation and TENEX-Related Activities
1975-02-01
A new echo rr ode, viz., echo non -wakeup characters and do not echo wakeup characters, was defined; and the assignments of four control characters...operations and, with certain controllers e.g. 3339 equivalent , simultaneous rotational positioning. Prior to installing tnis feature, BBN’s lyscem C... Control and Accounting System 3 B. RSEXEC Program Execution Environment 5 C. Management of Distributed Data Bases 6 III. TENEX RELATED ACTIVITIES
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Madaket Harbor, Nantucket, Massachusetts. Water Resources Improvement.
1977-07-01
will continue to be, important increases in the recreational use of land and water. The harbor area is an important arena for commercial shellfishing...an important arena for commercial shell fishing. The past few years have seen a rather rapid increase in residential land use. Construction has...beamc. Tnis material will be re-deposited,, viaj troio it 1-apfro1inr ox prior location. j, MADAKET HARBOR NANTUCKET, MASSACHUSETTS FEASIBILITY
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1985-03-01
005 4-, /nImII 1 liIm ulnli iiliiii I I UNCLASSIFIED SECURITY CLASSIFICATION OF TNIS PAGE ("on Data Bnter6t0 REPORT DOCUMENTATION PAGE READ...II different from ControllIng Office) 15. SECURITY CLASS (of thin report) Unclassified IS. OECLASSIFICATION/ DOWNGRADING SCMEDULE 1. DISTRIBUTION...EDITION OF I NOV 65 IS OBSOLETE UNCLASSIFIED N0102LF-0146601 1 UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Dote wrteed) ,IA UNCLASSIFIED
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Low-Level Convergence and the Prediction of Convective Precipitation in South Florida.
1981-02-01
Af" -Ao97 55 ILLINOIS STATE WATER SURVEY URBANA F/6 4/2 LOWLEVEL CONVERGENCE AND THE PREDICTION OF CONVECTIVE PRECIPIT-ETC(U) FEB 81 A I WATSON. R L...varying meteorological cond’tions and ti: == UNCLASSIFIED of day. SECURITY CLASSIFICATIOR OF TNIS PAGE (Whven Data Etered) State Water Survey...1981 1: 4. i0 The project "Low-level Convergence and the Prediction of Convective Precipitation" is a coordinated research effort by the State Water
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Role of the Chaplain in Ministry Related to Psychogenic Diseases.
1980-10-01
34 section of this report.) In fact, most physicians, prior to the advent of tne medical model, readily acknowlcdged the reality of the influence of the... virtually all diseases as having a psychogenic component. Although the G.A.S. process is a genetic reaction that, in the past, has served human beings... reality ie is very insecure. Tnis is manifest in his incessant desire to please hi’s superior; even if it means ignoring camarade’ie or congenial
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Scanning Cargo Containers with Tagged Neutrons
NASA Astrophysics Data System (ADS)
Viesti, G.; Botosso, C.; Fabris, D.; Lunardon, M.; Moretto, S.; Nebbia, G.; Pesente, S.; Zenoni, A.; Donzella, A.; Perot, B.; Carasco, C.; Bernard, S.; Mariani, A.; Szabo, J.-L.; Sannie, G.; Valkovic, V.; Sudac, D.; Nad, K.; Peerani, P.; Sequeira, V.; Salvato, M.; Moszynski, M.; Gierlik, M.; Klamra, W.; Le Tourneur, P.; Lhuissier, M.; Colonna, A.; Tintori, C.
2007-10-01
A new Tagged Neutron Inspection System (TNIS) able to detect illicit materials such as explosives and narcotics in cargo containers has been developed within the EURopean Illicit TRAfficing Countermeasures Kit (EURITRACK) project. After the R&D phase, the inspection portal has been installed and commissioned at the Rijeka seaport in Croatia, where it has been operated in connection with the existing X-ray scanner for a first two-month demonstration campaign. Results obtained are presented and discussed in this paper.
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1984-04-01
Directorate (Code 6032) V NAVAL AIR DEVELOPMENT CENTER Warminster, PA 18974 and I David A. Fender KETRON. INC. Warminster, PA 18974 DTlC APRIL 1984 ELECTE FINAL...A. D’Aulerio N62269-81-Z-0206 David A. Fender Task No. 630-1944 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMEN1T PROJECT, TASKAREA A...0102LF01401UNCLASSIFIED SECURITY CLAWFICATION OF TNIS PAGE (011t1 Die pewed) UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE w JIMu D#& Ent:ed) 9. Continued Louis A
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Materials Properties Data Management--Approaches to a Critical National Need
1983-09-01
President. Research & l)cvcloprn:nuDirector. Lexington Laboratory Air Products & Chemical%. IncThe Kendall Co. Dr. Alan Lawlev P.O. Box 538Lexington...of DelawareEngineering & Research Staff Newark, DE 19"! !1• Frd Motor Co. K M. Zwilsky. txcumie Daek:ior P.O. kx 2053 Dearborn. MI 4h 121 W.. X" 5/M...UNCLASSIFIED SECURITY CLASSIFICATION OF TNIS PAGE (When Dole EnElo4 -, UNCLASSIFIED UiCUNTIV CLASSIFICATION OF THIS PA6E(Uhm b0 filo generates the major
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1987-04-01
title of the study. This document. may be reproduced for use in other resetrch reports or educational pursuits contingent upon the fol ,owiog...stipulations: -- t’pr,,duCL n ri ;,|ht s do not extend to any copyrighted material that may be contained in the research report . A: r .pr)t uc d copi es inu:-st...s) o: tae report’s author(s). -- t for’nat mo.,i ficat ion is necessary to better serv, !,ie user’:; ieeds, adjustments may be made to tnis report
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The Pattern of Soviet Conduct in the Third World, Review and Preview. Part 2
1983-03-07
be quoted or copied without approval from OSD/Net Assessment. Aooession For DTIC TAB El Dit I-’I t Y " c•doi ;Avi.- ± end/or L i :itst I pc l 4•al IA...successcors have stooc, y that cecision. (Moscow odes riot recconioze tnis action.) Alth•cuph revolutionary Iran has i nioroved or estaolisned relations...far nesw tne world rar.et ievel and oepat, repotiaiions for a orice increase of roucniv t0w oercenz. ? y marc- I5d. witm the Soviets’ best otfer stiil
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Detection of Motion under Target Uncertainty and Peripheral Presentation.
1980-08-01
SCIENTIFIC RESEARCH (AISC) NOTICE OF TF A2:’fi1TL TO DDC This techi , ’-’ b n reviewed and in approved fc,r 1 c r e 1A,; AiiA 190-12 (7b). Distribution i...center direction). The response of the mecnanism is characterizable by the product of a)the intensity of the stimulus and b )the sensitivity of the...then are those of cells that are less responsive to such temporal modulation (FuKuda and Stone, 1974; Kirk# Levick and Cleland, j 1976). Tnis difference
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Exploratory Research on Personnel Long Range Planning
1982-05-01
rN4 and Joyce ShieldsI AR I ’I.0 04E~i Reserch nsttuteforU. S., Army K-Z Reearh Istiuteforthe Behavioral and Social Sciences May 1982 4S () 9 2~s.? 001...should be included in a personnel long ,ang plan (PLRP), DD , 0711W03 mno EOF@ 9 Nov sois@oneum UNCLASSIFIED SECURITY CLASSIFICATION OF TNIS PAE9 (ftaft...Accessions 3-16 3-7 FY1998 Distribution of Non-Prior-Service Accessions 3-17 3-8 FY1988 Distribution of Non-Prior-Service Accessions 3-18 * 3- 9 FY1989
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MCNP calculations for container inspection with tagged neutrons
NASA Astrophysics Data System (ADS)
Boghen, G.; Donzella, A.; Filippini, V.; Fontana, A.; Lunardon, M.; Moretto, S.; Pesente, S.; Zenoni, A.
2005-12-01
We are developing an innovative tagged neutrons inspection system (TNIS) for cargo containers: the system will allow us to assay the chemical composition of suspect objects, previously identified by a standard X-ray radiography. The operation of the system is extensively being simulated by using the MCNP Monte Carlo code to study different inspection geometries, cargo loads and hidden threat materials. Preliminary simulations evaluating the signal and the signal over background ratio expected as a function of the system parameters are presented. The results for a selection of cases are briefly discussed and demonstrate that the system can operate successfully in different filling conditions.
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1971-10-28
deviations of dry-bulb, wet-bulb (over) DD JA , 1473 UNCLASSIFIED SECURITY CLASSIFICATION OF ’HIS PAGE M ,-o De.*r., r n " CLASIVICATION or -IS PA:,Elxl Do...02,03-05 u u-02 00-02,03-05 00-02,03-05 18720-21-23 =IT 03-05.21-23 A*% i6_20.21-3 ~-o~- 00~1-0l20-05 00AZ1-02 2 00-02,03-05 o2, m 0-20-50-0 2 3- 8-Is...WEATMER COND1T!;niS FROX 4DUA’LY 033iNUATIZNS -~~t - to AC-’ otM ____ AIQ0as a- &T spa= 06;3 M IV, 23A4 3541 42.3 logg’ 53.2. 111 C C.1 35,1 29.7
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Simulation of a tagged neutron inspection system prototype
NASA Astrophysics Data System (ADS)
Donzella, A.; Boghen, G.; Bonomi, G.; Fontana, A.; Formisano, P.; Pesente, S.; Sudac, D.; Valkovic, V.; Zenoni, A.
2006-05-01
The illicit trafficking of explosive materials in cargo containers has become, in recent years, a serious problem. Currently used X-ray or γ-ray based systems provide only limited information about the elemental composition of the inspected cargo items. During the last years, a new neutron interrogation technique, named TNIS (Tagged Neutron Inspection System), has been developed, which should permit to determine the chemical composition of the suspect item by coincidence measurements between alpha particles and photons produced. A prototype of such a system for container inspection has been built, at the Institute Ruder Boskovic (IRB) in Zagreb, Croatia, for the European Union 6FP EURITRACK project. We present the results of a detailed simulation of the IRB prototype performed with the MCNP Monte Carlo program and a comparison with beam attenuation calculations performed with GEANT3/MICAP. Detector signals, rates and signal over background ratios have been calculated for 100 kg of TNT explosive located inside a cargo container filled with a metallic matrix of density 0.2 g/cm3. The case of an organic filling material is discussed too.
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Greenland elders and high school students offer perspectives on climate change and science
NASA Astrophysics Data System (ADS)
Showstack, Randy
2011-08-01
KANGERLUSSUAQ, GREENLAND—This small town in central western Greenland, which has a population of about 650 and a major airstrip dating from World War II, is a center for scientific research and a starting point for scientists working in the region and on Greenland's ice sheet to study climate change and other issues. The town, just north of the Arctic Circle, sits at the edge of the 190-kilometer-long Kangerlussuaq Fjord and straddles the Qinnguata Kuussua River estuary, whose source water is the Russell Glacier, about 20 kilometers to the east. Between Kanger—as some refer to the town—and the glacier, some Eskimo-Kalaallit elders held a traditional gathering last month and also offered their perspectives on climate change during an impromptu 14 July meeting with high school students and other visitors. The evening before that meeting, Ole Olsvig, Kurt Olsen, Avaruna Mathaeussen, and other high schoolers from Greenland were in a makeshift classroom at the back of a renovated former U.S. Army barracks in Kanger, which had served as a U.S. military base. The students, who said they care deeply about their traditional culture and also are very aware of recent changes in climate, were helping to make presentations about their summer science projects. A total of 16 high schoolers from Greenland, 3 from Denmark, and 5 from the United States were there, participating in Joint Science Education Project (JSEP) activities; JSEP is an international collaborative polar science education effort between Greenland, Denmark, and the United States that receives support from the U.S. National Science Foundation (NSF).
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Impact of e-liquid flavors on nicotine intake and pharmacology of e-cigarettes.
St Helen, Gideon; Dempsey, Delia A; Havel, Christopher M; Jacob, Peyton; Benowitz, Neal L
2017-09-01
To describe the effect of e-liquid flavors on nicotine intake and pharmacology of e-cigarettes. 11 males and 3 females participated in a 3-day inpatient crossover study with strawberry, tobacco, and their usual flavor e-liquid. Nicotine levels were nominally 18mg/mL in the strawberry (pH 8.29) and tobacco (pH 9.10) e-liquids and ranged between 3-18mg/mL in the usual brands (mean pH 6.80). Each day consisted of a 15-puff session followed by 4h of abstinence, then 90min of ad libitum use. Subjects used a KangerTech mini ProTank 3. After 15 puffs, the amount of nicotine inhaled and systemically retained were not significantly different between the strawberry and tobacco e-liquids but plasma AUC (0 → 180) was significantly higher with the strawberry e-liquid. While not significantly different, C max was 22% higher and various early time point AUCs to measure rate of rise of nicotine in blood ranged between 17 and 23% higher with the strawberry e-liquid compared to the tobacco e-liquid. During ad libitum use, systemic exposure to nicotine (AUC (0 → 90) ) was the same for the tobacco and usual brand e-liquids but were both significantly lower than after using the strawberry e-liquid. The usual flavors were more liked and satisfying than the strawberry and tobacco e-liquids. Flavors influence nicotine exposure through flavor liking, may affect rate of nicotine absorption possibly through pH effects, and contribute to heart rate acceleration and subjective effects of e-cigarettes. E-cigarette users titrate their nicotine exposure but the extent of titration may vary across flavors. Copyright © 2017 Elsevier B.V. All rights reserved.
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Lairson, David R; Dicarlo, Melissa; Deshmuk, Ashish A; Fagan, Heather B; Sifri, Randa; Katurakes, Nora; Cocroft, James; Sendecki, Jocelyn; Swan, Heidi; Vernon, Sally W; Myers, Ronald E
2014-04-01
Colorectal cancer (CRC) screening is cost-effective but underused. The objective of this study was to determine the cost-effectiveness of a mailed standard intervention (SI) and tailored navigation interventions (TNIs) to increase CRC screening use in the context of a randomized trial among primary care patients. Participants (n = 945) were randomized either to a usual care control group (n = 317), to an SI group (n = 316), or to a TNI group (n = 312). The SI group was sent both colonoscopy instructions and stool blood tests irrespective of baseline preference. TNI group participants were sent instructions for scheduling a colonoscopy, a stool blood test, or both based on their test preference, as determined at baseline; then, they received a navigation telephone call. Activity cost estimation was used to determine the cost of each intervention and to compute incremental cost-effectiveness ratios. Statistical uncertainty within the base case was assessed with 95% confidence intervals derived from net benefit regression analysis. The effects of uncertain parameters, such as the cost of planning, training, and involvement of those receiving "investigator salaries," were assessed with sensitivity analyses. Program costs of the SI were $167 per participant. The average cost of the TNI was $289 per participant. The TNI was more effective than the SI but substantially increased the cost per additional individual screened. Decision-makers need to consider cost structure, level of planning, and training required to implement these 2 intervention strategies and their willingness to pay for additional individuals screened to determine whether a tailored navigation would be justified and feasible. © 2013 American Cancer Society.
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NASA Astrophysics Data System (ADS)
Cunha, T.; Mendes, M.; Ferreira da Silva, F.; Eden, S.; García, G.; Bacchus-Montabonel, M.-C.; Limão-Vieira, P.
2018-04-01
We report on a combined experimental and theoretical study of electron-transfer-induced decomposition of adenine (Ad) and a selection of analog molecules in collisions with potassium (K) atoms. Time-of-flight negative ion mass spectra have been obtained in a wide collision energy range (6-68 eV in the centre-of-mass frame), providing a comprehensive investigation of the fragmentation patterns of purine (Pu), adenine (Ad), 9-methyl adenine (9-mAd), 6-dimethyl adenine (6-dimAd), and 2-D adenine (2-DAd). Following our recent communication about selective hydrogen loss from the transient negative ions (TNIs) produced in these collisions [T. Cunha et al., J. Chem. Phys. 148, 021101 (2018)], this work focuses on the production of smaller fragment anions. In the low-energy part of the present range, several dissociation channels that are accessible in free electron attachment experiments are absent from the present mass spectra, notably NH2 loss from adenine and 9-methyl adenine. This can be understood in terms of a relatively long transit time of the K+ cation in the vicinity of the TNI tending to enhance the likelihood of intramolecular electron transfer. In this case, the excess energy can be redistributed through the available degrees of freedom inhibiting fragmentation pathways. Ab initio theoretical calculations were performed for 9-methyl adenine (9-mAd) and adenine (Ad) in the presence of a potassium atom and provided a strong basis for the assignment of the lowest unoccupied molecular orbitals accessed in the collision process.
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An Electronic Cigarette Vaping Machine for the Characterization of Aerosol Delivery and Composition.
Havel, Christopher M; Benowitz, Neal L; Jacob, Peyton; St Helen, Gideon
2017-10-01
Characterization of aerosols generated by electronic cigarettes (e-cigarettes) is one method used to evaluate the safety of e-cigarettes. While some researchers have modified smoking machines for e-cigarette aerosol generation, these machines are either not readily available, not automated for e-cigarette testing or have not been adequately described. The objective of this study was to build an e-cigarette vaping machine that can be used to test, under standard conditions, e-liquid aerosolization and nicotine and toxicant delivery. The vaping machine was assembled from commercially available parts, including a puff controller, vacuum pump, power supply, switch to control current flow to the atomizer, three-way value to direct air flow to the atomizer, and three gas dispersion tubes for aerosol trapping. To validate and illustrate its use, the variation in aerosol generation was assessed within and between KangerTech Mini ProTank 3 clearomizers, and the effect of voltage on aerosolization and toxic aldehyde generation were assessed. When using one ProTank 3 clearomizer and different e-liquid flavors, the coefficient of variation (CV) of aerosol generated ranged between 11.5% and 19.3%. The variation in aerosol generated between ProTank 3 clearomizers with different e-liquid flavors and voltage settings ranged between 8.3% and 16.3% CV. Aerosol generation increased linearly at 3-6V across e-liquids and clearomizer brands. Acetaldehyde, acrolein, and formaldehyde generation increased markedly at voltages at or above 5V. The vaping machine that we describe reproducibly aerosolizes e-liquids from e-cigarette atomizers under controlled conditions and is useful for testing of nicotine and toxicant delivery. This study describes an electronic cigarette vaping machine that was assembled from commercially available parts. The vaping machine can be replicated by researchers and used under standard conditions to generate e-cigarette aerosols and characterize nicotine and
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Impact of e-liquid flavors on e-cigarette vaping behavior.
St Helen, Gideon; Shahid, Marian; Chu, Sherman; Benowitz, Neal L
2018-05-31
The primary objective of this pilot study was to describe the impact of e-cigarette liquid flavors on experienced e-cigarette users' vaping behavior. 11 males and 3 females participated in a 3-day inpatient crossover study using e-cigarettes with strawberry, tobacco, and their usual brand e-liquid. Nicotine levels were nominally 18 mg/mL in the strawberry and tobacco e-liquids and ranged between 3-18 mg/mL in the usual brands. On each day, participants had access to the study e-cigarette (KangerTech mini ProTank 3, 1.5 Ohms, 3.7 V) and the assigned e-liquid during a 90-minute videotaped ad libitum session. Average puff duration was significantly longer when using the strawberry e-liquid (3.2 ± 1.3 s, mean ± SD) compared to the tobacco e-liquid (2.8 ± 1.1 s) but the average number of puffs was not significantly different (strawberry, 73 ± 35; tobacco, 69 ± 46). Compared to the strawberry- and tobacco-flavored e-liquids, average puff duration was significantly longer (4.3 ± 1.6 s) and the average number of puffs was significantly higher (106 ± 67 puffs) when participants used their usual brand of e-liquid. Participants generally puffed more frequently in small groups of puffs (1-5 puffs) with the strawberry compared to the tobacco e-liquid and more frequently in larger groups (>10 puffs) with their usual brand. The strength of the relationship between vaping topography and nicotine intake and exposure were not consistent across e-liquids. Vaping behavior changes across e-liquids and influences nicotine intake. Research is needed to understand the mechanisms that underlie these behavioral changes, including e-liquid pH and related sensory effects, subjective liking, and nicotine effects. Copyright © 2018. Published by Elsevier B.V.