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Zhu Y, Peng J, Kang X, Xu C, Lan Z. The principal component analysis of the ring deformation in the nonadiabatic surface hopping dynamics. Phys Chem Chem Phys 2022; 24:24362-24382. [PMID: 36178471 DOI: 10.1039/d2cp03323b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The analysis of the leading active molecular motions in the on-the-fly trajectory surface hopping simulation provides the essential information to understand the geometric evolution in nonadiabatic dynamics. When the ring deformation is involved, the identification of the key active coordinates becomes challenging. A "hierarchical" protocol based on the dimensionality reduction and clustering approaches is proposed for the automatic analysis of the ring deformation in the nonadiabatic molecular dynamics. The representative system keto isocytosine is taken as the prototype to illustrate this protocol. The results indicate that the current hierarchical analysis protocol is a powerful way to clearly clarify both the major and minor active molecular motions of the ring distortion in nonadiabatic dynamics.
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Affiliation(s)
- Yifei Zhu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University, Guangzhou 510006, P. R. China. .,MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Jiawei Peng
- MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, P. R. China.,School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Xu Kang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University, Guangzhou 510006, P. R. China. .,MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Chao Xu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University, Guangzhou 510006, P. R. China. .,MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, P. R. China
| | - Zhenggang Lan
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University, Guangzhou 510006, P. R. China. .,MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou 510006, P. R. China
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Dynamic contract-enhanced CT-based radiomics for differentiation of pancreatobiliary-type and intestinal-type periampullary carcinomas. Clin Radiol 2021; 77:e75-e83. [PMID: 34753589 DOI: 10.1016/j.crad.2021.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 09/09/2021] [Indexed: 11/21/2022]
Abstract
AIM To investigate whether computed tomography (CT) radiomics can differentiate pancreatobiliary-type from intestinal-type periampullary carcinomas. MATERIALS AND METHODS CT radiomics of 96 patients (54 pancreatobiliary type and 42 intestinal type) with surgically confirmed periampullary carcinoma were assessed retrospectively. Volumes of interest (VOIs) were delineated manually. Radiomic features were extracted from preoperative CT images. A single-phase model and combined-phase model were constructed. Five-fold cross-validation and five machine-learning algorithms were utilised for model construction. The diagnostic performance of the models was evaluated by receiver operating characteristic (ROC) curves, and indicators included area under the curve (AUC), accuracy, sensitivity, specificity, and precision. ROC curves were compared using DeLong's test. RESULTS A total of 788 features were extracted on each phase. After feature selection using least absolute shrinkage and selection operator (LASSO) algorithm, the number of selected optimal feature was 18 (plain scan), nine (arterial phase), two (venous phase), 23 (delayed phase), 15 (three enhanced phases), and 29 (all phases), respectively. For the single-phase model, the delayed-phase model using the logistic regression (LR) algorithm showed the best prediction performance with AUC, accuracy, sensitivity, specificity, and precision of 0.89, 0.83, 0.80, 0.88, and 0.93, respectively. Two combined-phase models showed better results than the single-phase models. The model of all phases using the LR algorithm showed the best prediction performance with AUC, accuracy, sensitivity, specificity, and precision of 0.96, 0.88, 0.90, 0.93, and 0.92, respectively. CONCLUSION Radiomic models based on preoperative CT images can differentiate pancreatobiliary-type from intestinal-type periampullary carcinomas, in particular, the model of all phases using the LR algorithm.
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Peng J, Xie Y, Hu D, Lan Z. Analysis of bath motion in MM-SQC dynamics via dimensionality reduction approach: Principal component analysis. J Chem Phys 2021; 154:094122. [PMID: 33685149 DOI: 10.1063/5.0039743] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The system-plus-bath model is an important tool to understand the nonadiabatic dynamics of large molecular systems. Understanding the collective motion of a large number of bath modes is essential for revealing their key roles in the overall dynamics. Here, we applied principal component analysis (PCA) to investigate the bath motion in the basis of a large dataset generated from the symmetrical quasi-classical dynamics method based on the Meyer-Miller mapping Hamiltonian nonadiabatic dynamics for the excited-state energy transfer in the Frenkel-exciton model. The PCA method clearly elucidated that two types of bath modes, which either display strong vibronic coupling or have frequencies close to that of the electronic transition, are important to the nonadiabatic dynamics. These observations were fully consistent with the physical insights. The conclusions were based on the PCA of the trajectory data and did not involve significant pre-defined physical knowledge. The results show that the PCA approach, which is one of the simplest unsupervised machine learning dimensionality reduction methods, is a powerful one for analyzing complicated nonadiabatic dynamics in the condensed phase with many degrees of freedom.
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Affiliation(s)
- Jiawei Peng
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
| | - Yu Xie
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
| | - Deping Hu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
| | - Zhenggang Lan
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
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Mai S, González L. Identification of important normal modes in nonadiabatic dynamics simulations by coherence, correlation, and frequency analyses. J Chem Phys 2019; 151:244115. [DOI: 10.1063/1.5129335] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
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Li X, Hu D, Xie Y, Lan Z. Analysis of trajectory similarity and configuration similarity in on-the-fly surface-hopping simulation on multi-channel nonadiabatic photoisomerization dynamics. J Chem Phys 2018; 149:244104. [DOI: 10.1063/1.5048049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Xusong Li
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Sino-Danish Center for Education and Research/Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Deping Hu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Xie
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
| | - Zhenggang Lan
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Sino-Danish Center for Education and Research/Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
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Zhang W, Cai W, He B, Xiang N, Fang C, Jia F. A radiomics-based formula for the preoperative prediction of postoperative pancreatic fistula in patients with pancreaticoduodenectomy. Cancer Manag Res 2018; 10:6469-6478. [PMID: 30568506 PMCID: PMC6276820 DOI: 10.2147/cmar.s185865] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Objective The objective of the study was to develop and validate a radiomics-based formula for the preoperative prediction of postoperative pancreatic fistula (POPF) in patients undergoing pancreaticoduodenectomy (PD). Materials and methods A total of 117 consecutive patients who underwent PD were enrolled in this retrospective study. Radiomics features were extracted from portal venous phase computed tomography of the above patients. The least absolute shrinkage and selection operator logistic regression was used to construct a formula of Rad-score calculation. Then the performance of the formula was assessed with standard pancreatic Fistula Risk Score. Results The Rad-score could predict POPF with an area under the curve (AUC) of 0.8248 in the training cohort and of 0.7609 in the validation cohort. Patients who had experienced POPF generally had a statistically higher Rad-score than those who had not experienced POPF in both cohorts. The AUC of the Rad-score was statistically higher than the Fistula Risk Score for predicting POPF in both the training and validation cohort. Conclusion A novel radiomics-based formula was developed and validated for predicting POPF in patients who underwent PD, which provides a new method for identifying POPF risks and may help to improve informed decision-making in the prevention of POPF at low cost.
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Affiliation(s)
- Wenyu Zhang
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, People's Republic of China, .,Research Lab for Medical Imaging and Digital Surgery, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China,
| | - Wei Cai
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, People's Republic of China, .,Research Lab for Medical Imaging and Digital Surgery, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China,
| | - Baochun He
- Research Lab for Medical Imaging and Digital Surgery, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China, .,Shenzhen Key Laboratory of Minimally Invasive Surgical Robotics and System, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China,
| | - Nan Xiang
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, People's Republic of China,
| | - Chihua Fang
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, People's Republic of China,
| | - Fucang Jia
- Research Lab for Medical Imaging and Digital Surgery, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China, .,Shenzhen Key Laboratory of Minimally Invasive Surgical Robotics and System, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China,
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Abstract
In 1998, the first successful quantum control experiment with application to a molecular framework was conducted with a shaped laser pulse, optimizing the branching ratio between different organometallic reaction channels. This work induced a vast activity in quantum control during the next 10 years, and different optimization aims were achieved in the gas phase, liquid phase, and even in biologically relevant molecules like light-harvesting complexes. Accompanying and preceding this development were important advances in theoretical quantum control simulations. They predicted several control scenarios and explained how and why quantum control experiments work. After many successful proofs of concept in molecular science, the big challenge is to expand its huge conceptual potential of directly being able to steer nuclear and/or electronic motion to more applied implementations. In this Account, based on several recent advances, we give a personal evaluation of where the field of molecular quantum control is at the moment and especially where we think promising applications can be in the near future. One of these paths leads to synthetic chemistry. The synthesis of novel pharmaceutical compounds or natural products often involves many synthetic steps, each one devouring resources and lowering the product yield. Shaped laser pulses can possibly act as photonic reagents and shorten the synthetic route toward the desired product. Chemical synthesis usually takes place in solution, and by including explicit solvent molecules in our quantum control simulations, we were able to identify their highly inhomogeneous influence on chemical reactions and how this affects potential quantum control. More important, we demonstrated for a synthetically relevant example that these complications can be overcome in theory, and laser pulses can be optimized to initiate the desired carbon-carbon bond formation. Putting this into context with the recently emerging concept of flow chemistry, which brings several practical advantages to the application of laser pulses, we want to encourage experimental groups to exploit this concept. Another path was opened by several additions to the commonly used laser pulse optimization algorithm (optimal control theory, OCT), several of which were developed in our group. The OCT algorithm as such is a purely mathematical optimization procedure, with no direct relation to experimental requirements. This means that usually the electric fields obtained out of OCT optimizations do not resemble laser pulses that can be achieved experimentally. However, the previously mentioned additions are aimed at closing the gap toward the experiment. In a recent quantum control study of our group, these algorithmic developments came to fruition. We were able to suggest a shaped laser pulse which can induce a long-living wave packet in the excited state of uracil. This might pave the way for novel experiments dedicated to investigating the formation of biological photodamage in DNA and RNA. The pulse we suggest is surprisingly simple because of the extended OCT algorithm and fulfills all criteria to be experimentally accessible.
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Affiliation(s)
- Daniel Keefer
- Department Chemie, Ludwig-Maximilians-Universität München, D-81377 München, Germany
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Zauleck JPP, de Vivie-Riedle R. Constructing Grids for Molecular Quantum Dynamics Using an Autoencoder. J Chem Theory Comput 2017; 14:55-62. [DOI: 10.1021/acs.jctc.7b01045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Julius P. P. Zauleck
- Department Chemie, Ludwig-Maximilians-Universität München, D-81377 München, Germany
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Steffen J, Hartke B. Cheap but accurate calculation of chemical reaction rate constants from ab initio data, via system-specific, black-box force fields. J Chem Phys 2017; 147:161701. [DOI: 10.1063/1.4979712] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Li X, Xie Y, Hu D, Lan Z. Analysis of the Geometrical Evolution in On-the-Fly Surface-Hopping Nonadiabatic Dynamics with Machine Learning Dimensionality Reduction Approaches: Classical Multidimensional Scaling and Isometric Feature Mapping. J Chem Theory Comput 2017; 13:4611-4623. [DOI: 10.1021/acs.jctc.7b00394] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Xusong Li
- CAS
Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy
and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Sino-Danish
Center for Education and Research/Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Department
of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kgs. Lyngby, Denmark
| | - Yu Xie
- CAS
Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy
and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Deping Hu
- CAS
Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy
and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenggang Lan
- CAS
Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy
and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Sino-Danish
Center for Education and Research/Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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