Insight into the defluorination ability of per- and polyfluoroalkyl substances based on machine learning and quantum chemical computations

Author(s):  
Huiming Cao ◽  
Jianhua Peng ◽  
Zhen Zhou ◽  
Yuzhen Sun ◽  
Yawei Wang ◽  
...  
2016 ◽  
Vol 81 (12) ◽  
pp. 1393-1406 ◽  
Author(s):  
Marko Kojic ◽  
Milena Petkovic ◽  
Mihajlo Etinski

Avobenzone (4-tert-butyl-4?-methoxydibenzoylmethane) is one of the most widely used UVA filters in cosmetic sunscreens. Reactivity of avobenzone is complex and challenging to understand, due to a presence of transient tautomers. In this contribution we study chelated enol, rotamer and keto tautomers of a reduced model of avobenzone which are involved in keto-enol tautomerization. Two thermal tautomerization mechanisms are postulated and their transient structures are discussed. The computed vertical and adiabatic electronic excitation energies of tautomers provide an additional insight into excited state properties of the tautomers.


2010 ◽  
Vol 63 (7) ◽  
pp. 1013 ◽  
Author(s):  
Michael Winkler ◽  
Wolfram Sander

Within the past four decades, matrix isolation spectroscopy has emerged as the method of choice for obtaining direct structural information on benzynes and related dehydroaromatics. In combination with quantum chemical computations, detailed insight into the structure and reactivity of di-, tri-, and tetradehydrobenzenes has been obtained. This Review focuses on rather recent developments in aryne chemistry with a special emphasis on the matrix isolation of tridehydrobenzenes and related systems.


2020 ◽  
Author(s):  
Azhagiya Singam Ettayapuram Ramaprasad ◽  
Phum Tachachartvanich ◽  
Denis Fourches ◽  
Anatoly Soshilov ◽  
Jennifer C.Y. Hsieh ◽  
...  

Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) pose a substantial threat as endocrine disruptors, and thus early identification of those that may interact with steroid hormone receptors, such as the androgen receptor (AR), is critical. In this study we screened 5,206 PFASs from the CompTox database against the different binding sites on the AR using both molecular docking and machine learning techniques. We developed support vector machine models trained on Tox21 data to classify the active and inactive PFASs for AR using different chemical fingerprints as features. The maximum accuracy was 95.01% and Matthew’s correlation coefficient (MCC) was 0.76 respectively, based on MACCS fingerprints (MACCSFP). The combination of docking-based screening and machine learning models identified 29 PFASs that have strong potential for activity against the AR and should be considered priority chemicals for biological toxicity testing.


Matter ◽  
2021 ◽  
Author(s):  
Andrew S. Rosen ◽  
Shaelyn M. Iyer ◽  
Debmalya Ray ◽  
Zhenpeng Yao ◽  
Alán Aspuru-Guzik ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 930
Author(s):  
Fahimeh Hadavimoghaddam ◽  
Mehdi Ostadhassan ◽  
Ehsan Heidaryan ◽  
Mohammad Ali Sadri ◽  
Inna Chapanova ◽  
...  

Dead oil viscosity is a critical parameter to solve numerous reservoir engineering problems and one of the most unreliable properties to predict with classical black oil correlations. Determination of dead oil viscosity by experiments is expensive and time-consuming, which means developing an accurate and quick prediction model is required. This paper implements six machine learning models: random forest (RF), lightgbm, XGBoost, multilayer perceptron (MLP) neural network, stochastic real-valued (SRV) and SuperLearner to predict dead oil viscosity. More than 2000 pressure–volume–temperature (PVT) data were used for developing and testing these models. A huge range of viscosity data were used, from light intermediate to heavy oil. In this study, we give insight into the performance of different functional forms that have been used in the literature to formulate dead oil viscosity. The results show that the functional form f(γAPI,T), has the best performance, and additional correlating parameters might be unnecessary. Furthermore, SuperLearner outperformed other machine learning (ML) algorithms as well as common correlations that are based on the metric analysis. The SuperLearner model can potentially replace the empirical models for viscosity predictions on a wide range of viscosities (any oil type). Ultimately, the proposed model is capable of simulating the true physical trend of the dead oil viscosity with variations of oil API gravity, temperature and shear rate.


The Analyst ◽  
2021 ◽  
Author(s):  
Barnaby Ellis ◽  
Conor A Whitley ◽  
Safaa Al Jedani ◽  
Caroline Smith ◽  
Philip Gunning ◽  
...  

A novel machine learning algorithm is shown to accurately discriminate between oral squamous cell carcinoma (OSCC) nodal metastases and surrounding lymphoid tissue on the basis of a single metric, the...


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