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1. Polarization Induced Switching Effect in Graphene Nanoribbon Edge-Defect Junction

Author

Yin, G., Liang, Y. Y., Jiang, F., Chen, H., Wang, P., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

With nonequilibrium Green's function approach combined with density functional theory, we perform an ab initio calculation to investigate transport properties of graphene nanoribbon junctions self-consistently. Tight-binding approximation is applied to model the zigzag graphene nanoribbon (ZGNR) electrodes, and its validity is confirmed by comparison with GAUSSIAN03 PBC calculation of the same system. The origin of abnormal jump points usually appearing in the transmission spectrum is explained with the detailed tight-binding ZGNR band structure. Transport property of an edge defect ZGNR junction is investigated, and the tunable tunneling current can be sensitively controlled by transverse electric fields., Comment: 18 pages, 8 figures

Published
2009
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2. Ab initio study of single molecular transistor modulated by gate-bias

Author

Jiang, F., Zhou, Y. X., Chen, H., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We use a self-consistent method to study the current of the single molecular transistor modulated by the transverse gate-bias in the level of the first-principles calculations. The numerical results show that both the polyacene-dithiol molecules and the fused-ring oligothiophene molecules are the potential high-frequency molecular transistor controlled by the transverse field. The long molecules of the polyacene-dithiol or the fused-ring thiophene are in favor of realizing the gate-bias controlled molecular transistor. The theoretical results suggest the related experiments., Comment: 14 pages, 7 figures

Published
2006
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3. Unusual Length Dependence of Conductance of Some Oligomers

Author

Zhou, Y. X., Jiang, F., Chen, H., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

Recent experiment found a quantum length dependence of oligothiophene molecule conductance at low bias [Xu et al., nano Lett. \textbf{5}, 1491 (2005)], the long molecule has large conductance. By means of a first-principles method we obtain both the quantum length dependence of conductance at low bias and the classical length dependence of conductance at high bias region for oligothiophene. In between there is an oscillated conductance behavior. The transport behaviors are determined by the distinct electronic structures of the molecular compounds. The various conductance length dependence may appear for the organic compounds. Our further investigation finds that the classical conductance length dependence in polyphenanthrene dithiolates and another unusual conductance length dependence in polyacene ditholates: the quantum length dependence of conductance is at the high bias and the classical length dependence of conductance is at the low bias., Comment: 4 pages, 3 figures

Published
2006

4. Influence of Fe and Co on Phase Transitions in Ni-Mn-Ga Alloys

Author

Khovailo, V. V., Abe, T., Koledov, V. V., Matsumoto, M., Nakamura, H., Note, R., Ohtsuka, M., Shavrov, V. G., and Takagi, T.

Subjects
Condensed Matter - Materials Science
Abstract

Differential scanning calorimetry (DSC) and magnetic measurements were performed to study the influence of ferromagnetic 3-d transition elements Fe and Co on structural and magnetic properties of ferromagnetic shape memory alloys Ni2MnGa. Addition of Fe or Co on the Ni sites decreases the temperature of martensitic phase transition Tm, whereas addition of Co on the Mn sites results in a considerable increase of Tm. Magnetic measurement revealed that Curie temperature TC increases upon substitution of Fe or Co for Ni. This observation is of importance for design of high temperature ferromagnetic shape memory alloys., Comment: 4 pages, 3 figures

Published
2003

5. Magnetic properties of Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition

Author

Khovailo, V. V., Takagi, T., Tani, J., Levitin, R. Z., Cherechukin, A. A., Matsumoto, M., and Note, R.

Subjects
Condensed Matter - Materials Science
Abstract

Polycrystalline Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition are studied by differential scanning calorimetry, magnetic and resistivity measurements. Coupling of the magnetic and structural subsystems results in unusual magnetic features of the alloy. These uncommon magnetic properties of Ni2.18Mn0.82Ga are attributed to the first-order structural transition from a tetragonal ferromagnetic to a cubic paramagnetic phase., Comment: 4 pages, 4 figures, revtex4

Published
2002
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8. Report from the EPAA workshop: In vitro ADME in safety testing used by EPAA industry sectors

Author

Schroeder, K., Bremm, K.D., Alépée, N., Bessems, J.G.M., Blaauboer, B., Boehn, S.N., Burek, C., Coecke, S., Gombau, L., Hewitt, N.J., Heylings, J., Huwyler, J., Jaeger, M., Jagelavicius, M., Jarrett, N., Ketelslegers, H., Kocina, I., Koester, J., Kreysa, J., Note, R., Poth, A., Radtke, M., Rogiers, V., Scheel, J., Schulz, T., Steinkellner, H., Toeroek, M., Whelan, M., Winkler, P., and Diembeck, W.

Published
2011
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9. CATMoS: Collaborative Acute Toxicity Modeling Suite

Author

Mansouri, K, Karmaus, A, Fitzpatrick, J, Patlewicz, G, Pradeep, P, Alberga, D, Alepee, N, Allen, T, Allen, D, Alves, V, Andrade, C, Auernhammer, T, Ballabio, D, Bell, S, Benfenati, E, Bhattacharya, S, Bastos, J, Boyd, S, Brown, J, Capuzzi, S, Chushak, Y, Ciallella, H, Clark, A, Consonni, V, Daga, P, Ekins, S, Farag, S, Fedorov, M, Fourches, D, Gadaleta, D, Gao, F, Gearhart, J, Goh, G, Goodman, J, Grisoni, F, Grulke, C, Hartung, T, Hirn, M, Karpov, P, Korotcov, A, Lavado, G, Lawless, M, Li, X, Luechtefeld, T, Lunghini, F, Mangiatordi, G, Marcou, G, Marsh, D, Martin, T, Mauri, A, Muratov, E, Myatt, G, Nguyen, D, Nicolotti, O, Note, R, Pande, P, Parks, A, Peryea, T, Polash, A, Rallo, R, Roncaglioni, A, Rowlands, C, Ruiz, P, Russo, D, Sayed, A, Sayre, R, Sheils, T, Siegel, C, Silva, A, Simeonov, A, Sosnin, S, Southall, N, Strickland, J, Tang, Y, Teppen, B, Tetko, I, Thomas, D, Tkachenko, V, Todeschini, R, Toma, C, Tripodi, I, Trisciuzzi, D, Tropsha, A, Varnek, A, Vukovic, K, Wang, Z, Wang, L, Waters, K, Wedlake, A, Wijeyesakere, S, Wilson, D, Xiao, Z, Yang, H, Zahoranszky-Kohalmi, G, Zakharov, A, Zhang, F, Zhang, Z, Zhao, T, Zhu, H, Zorn, K, Casey, W, Kleinstreuer, N, Mansouri, Kamel, Karmaus, Agnes L, Fitzpatrick, Jeremy, Patlewicz, Grace, Pradeep, Prachi, Alberga, Domenico, Alepee, Nathalie, Allen, Timothy E H, Allen, Dave, Alves, Vinicius M, Andrade, Carolina H, Auernhammer, Tyler R, Ballabio, Davide, Bell, Shannon, Benfenati, Emilio, Bhattacharya, Sudin, Bastos, Joyce V, Boyd, Stephen, Brown, J B, Capuzzi, Stephen J, Chushak, Yaroslav, Ciallella, Heather, Clark, Alex M, Consonni, Viviana, Daga, Pankaj R, Ekins, Sean, Farag, Sherif, Fedorov, Maxim, Fourches, Denis, Gadaleta, Domenico, Gao, Feng, Gearhart, Jeffery M, Goh, Garett, Goodman, Jonathan M, Grisoni, Francesca, Grulke, Christopher M, Hartung, Thomas, Hirn, Matthew, Karpov, Pavel, Korotcov, Alexandru, Lavado, Giovanna J, Lawless, Michael, Li, Xinhao, Luechtefeld, Thomas, Lunghini, Filippo, Mangiatordi, Giuseppe F, Marcou, Gilles, Marsh, Dan, Martin, Todd, Mauri, Andrea, Muratov, Eugene N, Myatt, Glenn J, Nguyen, Dac-Trung, Nicolotti, Orazio, Note, Reine, Pande, Paritosh, Parks, Amanda K, Peryea, Tyler, Polash, Ahsan H, Rallo, Robert, Roncaglioni, Alessandra, Rowlands, Craig, Ruiz, Patricia, Russo, Daniel P, Sayed, Ahmed, Sayre, Risa, Sheils, Timothy, Siegel, Charles, Silva, Arthur C, Simeonov, Anton, Sosnin, Sergey, Southall, Noel, Strickland, Judy, Tang, Yun, Teppen, Brian, Tetko, Igor V, Thomas, Dennis, Tkachenko, Valery, Todeschini, Roberto, Toma, Cosimo, Tripodi, Ignacio, Trisciuzzi, Daniela, Tropsha, Alexander, Varnek, Alexandre, Vukovic, Kristijan, Wang, Zhongyu, Wang, Liguo, Waters, Katrina M, Wedlake, Andrew J, Wijeyesakere, Sanjeeva J, Wilson, Dan, Xiao, Zijun, Yang, Hongbin, Zahoranszky-Kohalmi, Gergely, Zakharov, Alexey V, Zhang, Fagen F, Zhang, Zhen, Zhao, Tongan, Zhu, Hao, Zorn, Kimberley M, Casey, Warren, Kleinstreuer, Nicole C, Mansouri, K, Karmaus, A, Fitzpatrick, J, Patlewicz, G, Pradeep, P, Alberga, D, Alepee, N, Allen, T, Allen, D, Alves, V, Andrade, C, Auernhammer, T, Ballabio, D, Bell, S, Benfenati, E, Bhattacharya, S, Bastos, J, Boyd, S, Brown, J, Capuzzi, S, Chushak, Y, Ciallella, H, Clark, A, Consonni, V, Daga, P, Ekins, S, Farag, S, Fedorov, M, Fourches, D, Gadaleta, D, Gao, F, Gearhart, J, Goh, G, Goodman, J, Grisoni, F, Grulke, C, Hartung, T, Hirn, M, Karpov, P, Korotcov, A, Lavado, G, Lawless, M, Li, X, Luechtefeld, T, Lunghini, F, Mangiatordi, G, Marcou, G, Marsh, D, Martin, T, Mauri, A, Muratov, E, Myatt, G, Nguyen, D, Nicolotti, O, Note, R, Pande, P, Parks, A, Peryea, T, Polash, A, Rallo, R, Roncaglioni, A, Rowlands, C, Ruiz, P, Russo, D, Sayed, A, Sayre, R, Sheils, T, Siegel, C, Silva, A, Simeonov, A, Sosnin, S, Southall, N, Strickland, J, Tang, Y, Teppen, B, Tetko, I, Thomas, D, Tkachenko, V, Todeschini, R, Toma, C, Tripodi, I, Trisciuzzi, D, Tropsha, A, Varnek, A, Vukovic, K, Wang, Z, Wang, L, Waters, K, Wedlake, A, Wijeyesakere, S, Wilson, D, Xiao, Z, Yang, H, Zahoranszky-Kohalmi, G, Zakharov, A, Zhang, F, Zhang, Z, Zhao, T, Zhu, H, Zorn, K, Casey, W, Kleinstreuer, N, Mansouri, Kamel, Karmaus, Agnes L, Fitzpatrick, Jeremy, Patlewicz, Grace, Pradeep, Prachi, Alberga, Domenico, Alepee, Nathalie, Allen, Timothy E H, Allen, Dave, Alves, Vinicius M, Andrade, Carolina H, Auernhammer, Tyler R, Ballabio, Davide, Bell, Shannon, Benfenati, Emilio, Bhattacharya, Sudin, Bastos, Joyce V, Boyd, Stephen, Brown, J B, Capuzzi, Stephen J, Chushak, Yaroslav, Ciallella, Heather, Clark, Alex M, Consonni, Viviana, Daga, Pankaj R, Ekins, Sean, Farag, Sherif, Fedorov, Maxim, Fourches, Denis, Gadaleta, Domenico, Gao, Feng, Gearhart, Jeffery M, Goh, Garett, Goodman, Jonathan M, Grisoni, Francesca, Grulke, Christopher M, Hartung, Thomas, Hirn, Matthew, Karpov, Pavel, Korotcov, Alexandru, Lavado, Giovanna J, Lawless, Michael, Li, Xinhao, Luechtefeld, Thomas, Lunghini, Filippo, Mangiatordi, Giuseppe F, Marcou, Gilles, Marsh, Dan, Martin, Todd, Mauri, Andrea, Muratov, Eugene N, Myatt, Glenn J, Nguyen, Dac-Trung, Nicolotti, Orazio, Note, Reine, Pande, Paritosh, Parks, Amanda K, Peryea, Tyler, Polash, Ahsan H, Rallo, Robert, Roncaglioni, Alessandra, Rowlands, Craig, Ruiz, Patricia, Russo, Daniel P, Sayed, Ahmed, Sayre, Risa, Sheils, Timothy, Siegel, Charles, Silva, Arthur C, Simeonov, Anton, Sosnin, Sergey, Southall, Noel, Strickland, Judy, Tang, Yun, Teppen, Brian, Tetko, Igor V, Thomas, Dennis, Tkachenko, Valery, Todeschini, Roberto, Toma, Cosimo, Tripodi, Ignacio, Trisciuzzi, Daniela, Tropsha, Alexander, Varnek, Alexandre, Vukovic, Kristijan, Wang, Zhongyu, Wang, Liguo, Waters, Katrina M, Wedlake, Andrew J, Wijeyesakere, Sanjeeva J, Wilson, Dan, Xiao, Zijun, Yang, Hongbin, Zahoranszky-Kohalmi, Gergely, Zakharov, Alexey V, Zhang, Fagen F, Zhang, Zhen, Zhao, Tongan, Zhu, Hao, Zorn, Kimberley M, Casey, Warren, and Kleinstreuer, Nicole C

Abstract

Background: Humans are exposed to tens of thousands of chemical substances that need to be assessed for their potential toxicity. Acute systemic toxicity testing serves as the basis for regulatory hazard classification, labeling, and risk management. However, it is cost- and time-prohibitive to evaluate all new and existing chemicals using traditional rodent acute toxicity tests. In silica models built using existing data facilitate rapid acute tox- icity predictions without using animals. Objkctivks: The U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) Acute Toxicity Workgroup organ- ized an international collaboration to develop in silica models for predicting acute oral toxicity based on five different end points: Lethal Dose 50 (LD50 value, U.S. Environmental Protection Agency hazard (four) categories, Globally Harmonized System for Classification and Labeling hazard (five) categories, very toxic chemicals [LD50 (LD50 ≤ 50 mg/kg)], and nontoxic chemicals (LD50 > 2,000 mg/kg). Mkthods: An acute oral toxicity data inventory for 11,992 chemicals was compiled, split into training and evaluation sets, and made available to 35 participating international research groups that submitted a total of 139 predictive models. Predictions that fell within the applicability domains of the submitted models were evaluated using external validation sets. These were then combined into consensus models to leverage strengths of individual approaches. Results: The resulting consensus predictions, which leverage the collective strengths of each individual model, form the Collaborative Acute Toxicity Modeling Suite (CATMoS). CATMoS demonstrated high performance in terms of accuracy and robustness when compared with in viva results. Discussion: CATMoS is being evaluated by regulatory agencies for its utility and applicability as a potential replacement for in viva rat acute oral toxicity studies. CATMoS predictions for more than 800,000 chemica

Published
2021

15. Current through single conjugated molecules: Calculations versus measurements.

Author

Liang, Y. Y., Zhou, Y. X., Chen, H., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
DENSITY functionals, GREEN'S functions, ELECTRODES, PERYLENE, ANTHRACENE
Abstract

We use density functional theory based nonequilibrium Green’s function to calculate the current through the different rodlike molecules at the finite temperatures self-consistently, which was compared to the experimental measurements presented by Reichert et al. [Phys. Rev. Lett. 88, 176804 (2002)] and by Mayor et al. [Angew. Chem. Int. Ed. 42, 5834 (2003)], respectively. Our results agree with the measurements very well, especially for the bias around ±1.0 V. The investigation of the topological effect for the symmetrical molecule reveals the fact that the para position compound provides a considerably larger conductance than the meta one. [ABSTRACT FROM AUTHOR]

Published
2008
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16. First-principles study of length dependence of conductance in alkanedithiols.

Author

Zhou, Y. X., Jiang, F., Chen, H., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
ELECTRON transport, ENERGY transfer, ELECTRODIFFUSION, TRANSPORT theory, DENSITY functionals, MOLECULAR structure
Abstract

Electronic transport properties of alkanedithiols are calculated by a first-principles method based on density functional theory and nonequilibrium Green’s function formalism. At small bias, the I-V characteristics are linear and the resistances conform to the Magoga’s exponential law. The calculated length-dependent decay constant γ which reflects the effect of internal molecular structure is in accordance with most experiments quantitatively. Also, the calculated effective contact resistance R0 is in good agreement with the results of repeatedly measuring molecule-electrode junctions [B. Xu and N. Tao, Science 301, 1221 (2003)]. [ABSTRACT FROM AUTHOR]

Published
2008
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17. Ab initio study of single-molecule rotation switch based on nonequilibrium Green’s function theory.

Author

Liang, Y. Y., Jiang, F., Zhou, Y. X., Chen, H., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
MOLECULAR rotation, MOLECULAR dynamics, STEREOCHEMISTRY, NONEQUILIBRIUM statistical mechanics, GREEN'S functions, DIFFERENTIAL equations, POTENTIAL theory (Mathematics)
Abstract

The bistable molecular switches have been studied theoretically based on the first-principles calculation. The geometry structures of the switches studied in this paper can be triggered between two symmetrical structures by using an external applied electric field. I-V characteristic curves of the different molecule configurations have been calculated, and distinguishability of these characteristic curves indicates a switching behavior, the performance of which can be improved significantly by some suitable donors and acceptors. [ABSTRACT FROM AUTHOR]

Published
2007
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18. Self-consistent study of single molecular transistor modulated by transverse field.

Author

Jiang, F., Zhou, Y. X., Chen, H., Note, R., Mizuseki, H., and Kawazoe, Y.

Subjects
THIOPHENES, DENSITY functionals, ORGANIC semiconductors, FIELD-effect transistors, MOLECULAR electronics, NANOSTRUCTURED materials
Abstract

We use a self-consistent method to study the current of the single molecular transistor modulated by the transverse field in the level of the density functional theory and the nonequilibrium Green function method. The numerical results show that both the polyacene-dithiol molecules and the fused-ring thiophene molecules are the potential high-frequency molecular transistors controlled by the transverse field. The longer molecules of the polyacene-dithiol or the fused-ring thiophene are in favor of realizing the gate-bias controlled molecular transistor. The theoretical results suggest the related experiments. [ABSTRACT FROM AUTHOR]

Published
2006
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44. Production of single Al64Cu23Fe13icosahedral quasicrystal with the Czochralski method

Author

Yokoyama, Y, Fukaura, K, Sunada, H, Note, R, Hiraga, K, and Inoue, A

Abstract

We have investigated formation mechanisms of the icosahedral (i-) phase in a Cu-enriched region of the Al–Cu–Fe system. The formation of i-phase in the Al–Cu–Fe alloy system is characterized by the peritectic reaction: λ2+L→I (λ2is an Al3Fe compound with over 5at.% Cu), which has been observed even in the Cu-enriched region. Therefore, we have tried to avoid the λ2-crystallization by preliminary metallurgical treatments for molten alloy. As a result, we have succeeded in growing a single Al64Cu23Fe13i-quasicrystal with the Czochralski method.

Published
2000
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45. Synthesis and Evaluation of “AZT-HEPT”, “AZT-Pyridinone”, and “ddC-HEPT” Conjugates as Inhibitors of HIV Reverse Transcriptase<SUP>1</SUP><BBR RID="jm991125lb00001">

Author

Pontikis, R., Dolle, V., Guillaumel, J., Dechaux, E., Note, R., Nguyen, C. H., Legraverend, M., Bisagni, E., Aubertin, A.-M., Grierson, D. S., and Monneret, C.

Abstract

To test the concept that HIV reverse transcriptase could be effectively inhibited by “mixed site inhibitors”, a series of seven conjugates containing both a nucleoside analogue component (AZT 1, ddC 2) and a nonnucleoside type inhibitor (HEPT analogue 12, pyridinone 27) were synthesized and evaluated for their ability to block HIV replication. The (N-3 and C-5)AZT-HEPT conjugates 15, 22, and 23 displayed 2−5 μM anti-HIV activity, but they had no effect on the replication of HIV-2 or the HIV-1 strain with the Y181C mutation. The (C-5)AZT-pyridinone conjugates 34−37 were found to be inactive. In marked contrast, the ddC-HEPT molecule 26 displayed the same potency (EC50 = 0.45 μM) against HIV-1 (wild type and the Y181C nevirapine-resistant strain) and HIV-2 in cell culture. No synergistic effect was observed for these bis-substrate inhibitors, suggesting that the two individual inhibitor components in these molecules do not bind simultaneously in their respective sites. Interestingly, however, the results indicate that the AZT-HEPT conjugates and the ddC-HEPT derivative 26 inhibit reverse transcriptase (RT) in an opposite manner. One explanation for this difference is that the former compounds interact preferentially with the hydrophobic pocket in RT, whereas 26 (after supposed triphosphorylation) inhibits RT through binding in the catalytic site.

Published
2000

50. CATMoS: Collaborative Acute Toxicity Modeling Suite

Author

Tyler Peryea, Ahsan Habib Polash, Alessandra Roncaglioni, Daniel M. Wilson, Warren Casey, Patricia Ruiz, Nathalie Alépée, Sherif Farag, Giovanna J. Lavado, Kimberley M. Zorn, Alexey V. Zakharov, Davide Ballabio, Katrina M. Waters, Risa Sayre, Giuseppe Felice Mangiatordi, Orazio Nicolotti, Nicole Kleinstreuer, Pankaj R. Daga, Sean Ekins, Kamel Mansouri, Liguo Wang, Judy Strickland, Matthew J. Hirn, Sudin Bhattacharya, Dac-Trung Nguyen, Emilio Benfenati, Ignacio J. Tripodi, Amanda K. Parks, Garett Goh, Dennis G. Thomas, Glenn J. Myatt, Prachi Pradeep, Gergely Zahoranszky-Kohalmi, Anton Simeonov, Arthur C. Silva, Grace Patlewicz, Timothy Sheils, Stephen Boyd, Agnes L. Karmaus, Ahmed Sayed, Alex M. Clark, Todd M. Martin, Pavel Karpov, Jeffery M. Gearhart, Robert Rallo, D Allen, Charles Siegel, Zhen Zhang, Zijun Xiao, Alexander Tropsha, Stephen J. Capuzzi, Alexandru Korotcov, Carolina Horta Andrade, Noel Southall, Viviana Consonni, Igor V. Tetko, Jeremy M. Fitzpatrick, Andrew J. Wedlake, Denis Fourches, Zhongyu Wang, Vinicius M. Alves, Eugene N. Muratov, Timothy E. H. Allen, Andrea Mauri, James B. Brown, Alexandre Varnek, Yun Tang, Sanjeeva J. Wijeyesakere, Daniel P. Russo, Cosimo Toma, Christopher M. Grulke, Michael S. Lawless, Domenico Gadaleta, Paritosh Pande, Thomas Hartung, Jonathan M. Goodman, Kristijan Vukovic, Joyce V. Bastos, Daniela Trisciuzzi, Fagen F. Zhang, Domenico Alberga, Thomas Luechtefeld, Dan Marsh, Tyler R. Auernhammer, Shannon M. Bell, Xinhao Li, Brian J. Teppen, F. Lunghini, Sergey Sosnin, Hao Zhu, Feng Gao, Craig Rowlands, Tongan Zhao, R Todeschini, Valery Tkachenko, Francesca Grisoni, Hongbin Yang, Yaroslav Chushak, Maxim V. Fedorov, Heather L. Ciallella, Gilles Marcou, Goodman, Jonathan [0000-0002-8693-9136], Yang, Hongbin [0000-0001-6740-1632], Apollo - University of Cambridge Repository, Mansouri, K, Karmaus, A, Fitzpatrick, J, Patlewicz, G, Pradeep, P, Alberga, D, Alepee, N, Allen, T, Allen, D, Alves, V, Andrade, C, Auernhammer, T, Ballabio, D, Bell, S, Benfenati, E, Bhattacharya, S, Bastos, J, Boyd, S, Brown, J, Capuzzi, S, Chushak, Y, Ciallella, H, Clark, A, Consonni, V, Daga, P, Ekins, S, Farag, S, Fedorov, M, Fourches, D, Gadaleta, D, Gao, F, Gearhart, J, Goh, G, Goodman, J, Grisoni, F, Grulke, C, Hartung, T, Hirn, M, Karpov, P, Korotcov, A, Lavado, G, Lawless, M, Li, X, Luechtefeld, T, Lunghini, F, Mangiatordi, G, Marcou, G, Marsh, D, Martin, T, Mauri, A, Muratov, E, Myatt, G, Nguyen, D, Nicolotti, O, Note, R, Pande, P, Parks, A, Peryea, T, Polash, A, Rallo, R, Roncaglioni, A, Rowlands, C, Ruiz, P, Russo, D, Sayed, A, Sayre, R, Sheils, T, Siegel, C, Silva, A, Simeonov, A, Sosnin, S, Southall, N, Strickland, J, Tang, Y, Teppen, B, Tetko, I, Thomas, D, Tkachenko, V, Todeschini, R, Toma, C, Tripodi, I, Trisciuzzi, D, Tropsha, A, Varnek, A, Vukovic, K, Wang, Z, Wang, L, Waters, K, Wedlake, A, Wijeyesakere, S, Wilson, D, Xiao, Z, Yang, H, Zahoranszky-Kohalmi, G, Zakharov, A, Zhang, F, Zhang, Z, Zhao, T, Zhu, H, Zorn, K, Casey, W, Kleinstreuer, N, Chimie de la matière complexe (CMC), and Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Health, Toxicology and Mutagenesis, 010501 environmental sciences, Bioinformatics, 01 natural sciences, 03 medical and health sciences, 0302 clinical medicine, Government Agencies, CHIM/01 - CHIMICA ANALITICA, Toxicity Tests, Acute, Medicine, Animals, Computer Simulation, 030212 general & internal medicine, United States Environmental Protection Agency, consensus analysi, 0105 earth and related environmental sciences, QSAR, business.industry, Research, Acute Toxicity, Public Health, Environmental and Occupational Health, Acute toxicity, United States, 3. Good health, Rats, machine learning, Systemic toxicity, 13. Climate action, Erratum, business, [CHIM.CHEM]Chemical Sciences/Cheminformatics, Potential toxicity
Abstract

BACKGROUND: Humans are exposed to tens of thousands of chemical substances that need to be assessed for their potential toxicity. Acute systemic toxicity testing serves as the basis for regulatory hazard classification, labeling, and risk management. However, it is cost- and time-prohibitive to evaluate all new and existing chemicals using traditional rodent acute toxicity tests. In silico models built using existing data facilitate rapid acute toxicity predictions without using animals. OBJECTIVES: The U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) Acute Toxicity Workgroup organized an international collaboration to develop in silico models for predicting acute oral toxicity based on five different end points: Lethal Dose 50 (LD50 value, U.S. Environmental Protection Agency hazard (four) categories, Globally Harmonized System for Classification and Labeling hazard (five) categories, very toxic chemicals [LD50 (LD50≤50mg/kg)], and nontoxic chemicals (LD50>2,000mg/kg). METHODS: An acute oral toxicity data inventory for 11,992 chemicals was compiled, split into training and evaluation sets, and made available to 35 participating international research groups that submitted a total of 139 predictive models. Predictions that fell within the applicability domains of the submitted models were evaluated using external validation sets. These were then combined into consensus models to leverage strengths of individual approaches. RESULTS: The resulting consensus predictions, which leverage the collective strengths of each individual model, form the Collaborative Acute Toxicity Modeling Suite (CATMoS). CATMoS demonstrated high performance in terms of accuracy and robustness when compared with in vivo results. DISCUSSION: CATMoS is being evaluated by regulatory agencies for its utility and applicability as a potential replacement for in vivo rat acute oral toxicity studies. CATMoS predictions for more than 800,000 chemicals have been made available via the National Toxicology Program's Integrated Chemical Environment tools and data sets (ice.ntp.niehs.nih.gov). The models are also implemented in a free, standalone, open-source tool, OPERA, which allows predictions of new and untested chemicals to be made. https://doi.org/10.1289/EHP8495.

Published
2021
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