85 results on '"Yizhen Tang"'
Search Results
2. The mechanism and therapeutic strategies for neovascular glaucoma secondary to diabetic retinopathy
- Author
-
Yizhen Tang, Yan Shi, and Zhigang Fan
- Subjects
Endocrinology, Diabetes and Metabolism - Abstract
Neovascular glaucoma (NVG) is a devastating secondary glaucoma characterized by the appearance of neovascular over the iris and the proliferation of fibrovascular tissue in the anterior chamber angle. Proliferative diabetic retinopathy (PDR) is one of the leading causes of NVG. Currently increasing diabetes population drive the prevalence rate of NVG into a fast-rising lane. The pathogenesis underlying NVG makes it refractory to routine management for other types of glaucoma in clinical practice. The combination of panretinal photocoagulation (PRP), anti-vascular endothelial growth factor (VEGF) injections, anti-glaucoma drugs, surgical intervention as well as blood glucose control is needed. Early diagnosis and aggressive treatment in time are crucial in halting the neovascularization process and preserving vision. This review provides an overview of NVG secondary to diabetic retinopathy (DR), including the epidemiology, pathogenesis and management, so as to provide a better understanding as well as potential therapeutic strategies for future treatment.
- Published
- 2023
- Full Text
- View/download PDF
3. Theoretical study of the mechanism and kinetics of the atmospheric reaction of acrylic acid with NO 3 radical
- Author
-
Jingyu Sun, Weikang Xiao, Yizhen Tang, and Yunju Zhang
- Subjects
Physical and Theoretical Chemistry ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics - Published
- 2022
- Full Text
- View/download PDF
4. Association between HSP-Specific T-Cell Counts and Retinal Nerve Fiber Layer Thickness in Patients with Primary Open-Angle Glaucoma
- Author
-
Chhavi Saini, Shuhong Jiang, Julia Devlin, Li Pan, Yizhen Tang, Jing Tang, Jessica A. Sun, Maltish M. Lorenzo, Qingyi Wang, Louis R. Pasquale, Kin-Sang Cho, Dong Feng Chen, and Lucy Q. Shen
- Subjects
General Medicine - Published
- 2023
- Full Text
- View/download PDF
5. Comment on 'Theoretical study of the NO3 radical reaction with CH2ClBr, CH2ICl, CH2BrI, CHCl2Br, and CHClBr2' by I. Alkorta, J. M. C. Plane, J. Elguero, J. Z. Dávalos, A. U. Acuña and A. Saiz-Lopez, Phys. Chem. Chem. Phys. 2022, 24, 14365
- Author
-
Claus Jørgen Nielsen and Yizhen Tang
- Subjects
General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
The NO3 radical reactions are deceivingly simple, but they are extremely difficult to describe by quantum chemistry methods due to symmetry breaking.
- Published
- 2023
- Full Text
- View/download PDF
6. A new theoretical investigation on ·OH initiated oxidation of acephate in the environment: mechanism, kinetics, and toxicity
- Author
-
Hui Zhao, Shuangjun Wang, Jingyu Sun, Chenggang Lu, and Yizhen Tang
- Subjects
Kinetics ,Organophosphorus Compounds ,Hydroxyl Radical ,Atmosphere ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,Animals ,Water ,General Medicine ,Management, Monitoring, Policy and Law ,Pesticides ,Oxidation-Reduction ,Rats - Abstract
The degradation of acephate by OH radicals in the environment.
- Published
- 2022
7. Investigation on the adverse impacts of electrochemically produced ClO
- Author
-
Wei, Yan, Jinghua, Chen, Jingli, Wu, Yifan, Li, Yijie, Liu, Qipeng, Yang, Yizhen, Tang, and Bo, Jiang
- Subjects
Halogens ,Chlorides ,Phenol ,Chlorella ,Wastewater ,Electrodes ,Oxidation-Reduction ,Water Pollutants, Chemical - Abstract
The presence of chloride ions can facilitate the COD removal efficiency due to the involvement of active chlorine species in the electro-oxidation process, but few attentions have been paid to the negative effect of the electro-generated oxychlorides on electro-oxidation performance. In this study, the effects of oxychlorides were investigated as functions of current density and phenol concentration using DSA anodes in terms of the evaluation of the COD removal performance and the biological toxicity. The results show that oxychlorides formed in the electro-oxidation system could result in the over-evaluation of the COD removal performance. Increasing current density (15-50 mA cm
- Published
- 2022
8. OH-initiated degradation of 1,2,3-trimethylbenzene in the atmosphere and wastewater: Mechanisms, kinetics, and ecotoxicity
- Author
-
Hui Zhao, Shuangjun Wang, Jingyu Sun, Yunju Zhang, and Yizhen Tang
- Subjects
Mammals ,Environmental Engineering ,Hydroxyl Radical ,Atmosphere ,Wastewater ,Pollution ,Hydrocarbons, Aromatic ,Rats ,Kinetics ,Environmental Chemistry ,Animals ,Waste Management and Disposal ,Oxidation-Reduction ,Nitrobenzenes - Abstract
1,2,3-Trimethylbenzene (1,2,3-TMB) is an important volatile organic compound (VOC) present in petroleum wastewater and the atmosphere. This compound can be degraded by OH radicals via abstraction, addition and substitution mechanisms. Results show that the addition mechanism is dominant and H-abstraction is subdominant, while methyl abstraction and substitution mechanisms are negligible in the gas and aqueous phases. Moreover, H-abstraction products undergo further reactions with O
- Published
- 2022
9. Ganglion Cell Complex Parameters in Primary Angle Closure Suspects
- Author
-
Shuning Li, Kai Cao, Xiaohua Pan, Yizhen Tang, Fancheng Yan, Yue Yang, Hui Feng, Ying Han, and Zhongyin Hu
- Subjects
Retinal Ganglion Cells ,Related factors ,medicine.medical_specialty ,Waist ,Cell complex ,business.industry ,Gonioscopy ,General Medicine ,Axial length ,Spherical Refractive Error ,Sensory Systems ,Ganglion ,Cellular and Molecular Neuroscience ,Ophthalmology ,medicine.anatomical_structure ,Lens thickness ,Humans ,Medicine ,In patient ,Glaucoma, Angle-Closure ,business ,Intraocular Pressure ,Tomography, Optical Coherence - Abstract
Introduction: This study aimed to investigate the ganglion cell complex (GCC) parameters in primary angle closure suspects (PACS) and identify the related factors. Methods: A total of 731 subjects, including 289 subjects with PACS and 442 subjects without PACS, underwent RTVue XR OCT. GCC parameters were compared between the two groups. The linear mixed-effects model was performed to evaluate the relationships between the GCC parameters and related factors. Results: Significant differences were found in gender, age, spherical refractive error, height, waist, anterior chamber depth, lens thickness, axial length, superior GCC thickness, ganglion cell complex focal loss volume, ganglion cell complex global loss volume, and ganglion cell complex root mean square between PACS and normal controls. The linear mixed-effects model showed that age ( p = 0.008) and blood glucose ( p = 0.001) were negatively correlated with average GCC thickness in PACS subjects, and PACS ( p = 0.036) and age ( p < 0.001) were the key influencing factors for average GCC thickness. Conclusion: GCC parameters in PACS subjects are different from those in normal controls. Careful explanation should be considered when evaluating changes of GCC parameters in patients with PACD.
- Published
- 2021
- Full Text
- View/download PDF
10. Theoretical investigations on the reactions of criegee intermediates with SO 2 to form SO 3
- Author
-
Hui Zhao, Shuangjun Wang, Chenggang Lu, Yizhen Tang, and Jing Guan
- Subjects
Organic Chemistry ,Physical and Theoretical Chemistry - Published
- 2022
- Full Text
- View/download PDF
11. Metabolomics in Primary Open Angle Glaucoma: A Systematic Review and Meta-Analysis
- Author
-
Yizhen Tang, Simran Shah, Kin-Sang Cho, Xinghuai Sun, and Dong Feng Chen
- Subjects
General Neuroscience - Abstract
Glaucoma is a leading cause of blindness worldwide. It is suggested that primary open angle glaucoma (POAG), the most common form of glaucoma, may be associated with significant metabolic alternations, but the systemic literature review and meta-analysis in the area have been missing. Altered metabolomic profiles in the aqueous humor and plasma may serve as possible biomarkers for early detection or treatment targets. In this article, we performed a systematic meta-analysis of the current literature surrounding the metabolomics of patients with POAG and metabolites associated with the disease. Results suggest several metabolites found to be specifically altered in patients with POAG, suggesting broad generalizability and pathways for future research.
- Published
- 2022
- Full Text
- View/download PDF
12. Investigations on mechanisms, kinetics, and ecotoxicity in OH-initiated degradation of 1,2,4,5-tetramethylbenzene in the environment
- Author
-
Hui Zhao, Jingyu Sun, Yunju Zhang, Shuangjun Wang, Chenggang Lu, Yizhen Tang, Jing Guan, and Yaru Pan
- Subjects
Kinetics ,Hydroxyl Radical ,Atmosphere ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Benzene ,General Medicine ,Wastewater ,Pollution - Abstract
As one of the volatile organic compounds (VOCs) in the environment, 1,2,4,5-tetramethylbenzene (1,2,4,5-TeMB) present in oily wastewater, and it can occur substitution, abstraction, and addition reactions with OH radicals in the atmosphere and wastewater. Electrostatic potential (ESP) and average local ionization energy (ALIE) prediction indicate that H atoms from CH
- Published
- 2022
13. Chlorate induced false reduction in chemical oxygen demand (COD) based on standard dichromate method: Countermeasure and mechanism
- Author
-
Huiji Xiao, Wei Yan, Zekun Zhao, Yizhen Tang, Yifan Li, Qipeng Yang, Siyi Luo, and Bo Jiang
- Subjects
Biological Oxygen Demand Analysis ,Environmental Engineering ,Ecological Modeling ,Wastewater ,Pollution ,Water Purification ,Oxygen ,Chlorates ,Sulfites ,Waste Management and Disposal ,Oxidation-Reduction ,Water Pollutants, Chemical ,Water Science and Technology ,Civil and Structural Engineering - Abstract
Deliberate addition of mildly oxidative chlorate (ClO
- Published
- 2022
14. Highly efficient and mild electrochemical degradation of bentazon by nano-diamond doped PbO2 anode with reduced Ti nanotube as the interlayer
- Author
-
Yijie Liu, Muhammad Akram, Bo Jiang, Xing Xu, Sun Tong, Su Qing, and Yizhen Tang
- Subjects
Electrolysis ,Materials science ,Inorganic chemistry ,Oxalic acid ,02 engineering and technology ,Electrolyte ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Anode ,law.invention ,Biomaterials ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,law ,Electrode ,0210 nano-technology ,Glyoxylic acid - Abstract
Anodic oxidation based on PbO2 anode has been demonstrated as the feasible approach for the decontamination of organic pollutants; however, the performance of this process is hindered by its ordinary electrochemical activity and relatively low stability. In this study, we fabricated an efficient Ti/TiO2-RNTs/Sb-SnO2/PbO2-ND electrode with electrochemically reduced TiO2 nanotubes as the interlayer and nano-diamond as the dopant. As compared with other electrodes, the constructed Ti/TiO2-RNTs/Sb-SnO2/PbO2-ND exhibited higher oxygen evolution overpotential, larger active area and less charge transfer resistance. Thus, the average current efficiency of 30% could be attained at 120 min with TiO2-NTs/Sb-SnO2/PbO2, which was 1.5 times higher in comparison with the typical Ti/Sb-SnO2/PbO2 electrode. It was found that the removal efficiency of COD could be increased from 49% to 69% after 120 min treatment in the presence of 10 mM Cl−1 in the electrolyte. After 6 h of electrolysis, 74% of TOC was removed and 31% and 22% of initial N was transformed into NH4+ and NO3− ions, respectively. And oxalic acid, glyoxylic acid, malonic acid and acetic acid were identified quantitatively as the intermediate products. Finally, it was estimated that the accelerated service life of Ti/TiO2-RNTs/Sb-SnO2/PbO2-ND electrode was approximately three times of Ti/Sb-SnO2/PbO2 electrode. Generally, this study is of great interest for the engineering community to design an efficient electrode material for the wastewater treatment.
- Published
- 2020
- Full Text
- View/download PDF
15. Computational study on the mechanisms and kinetics of the CH2BrO2 + ClO reaction in the atmosphere
- Author
-
Yunju Zhang, Bing He, and Yizhen Tang
- Subjects
010504 meteorology & atmospheric sciences ,Chemistry ,General Chemical Engineering ,Kinetics ,General Chemistry ,Time-dependent density functional theory ,010501 environmental sciences ,01 natural sciences ,Product distribution ,Reaction rate constant ,Potential energy surface ,SN2 reaction ,Physical chemistry ,Density functional theory ,Singlet state ,0105 earth and related environmental sciences - Abstract
The singlet and triplet potential energy surfaces for the CH2BrO2 + ClO reaction are studied at the CCSD(T)/cc-pVTZ//B3LYP/6-311++G(d,p) level. CH2BrO2 is revealed to react with ClO through two kinds of mechanisms on the triplet potential energy surface (PES), namely, SN2 displacement and H-abstraction, and the production of P3 (CHBrO2 + HOCl) via H-abstraction is the dominant channel. Addition/elimination and SN2 displacement mechanisms exist on the singlet PES and are more complicated. The RRKM calculations of the mechanism and product distribution in the CH2BrO2 + ClO reaction show that the stabilization of IM1 (CH2BrOOOBr) is dominant at T ≤ 600 K, while the pathway of producing P1 (CHBrO + HO2 + Cl) occupies the entire reaction at T > 600 K. The total rate constants are independent of pressure, while the individual rate constants are sensitive to pressure. The lifetime of CH2BrO2 in the presence of ClO is estimated to be 20.27 h. Moreover, time-dependent density functional theory (TDDFT) calculations suggest that IM1 (CH2BrOOOCl), IM2 (CH2BrOOClO) and IM3 (CH2BrOClO2) will photolyze under the sunlight.
- Published
- 2020
- Full Text
- View/download PDF
16. Degradation of mevinphos and monocrotophos by OH radicals in the environment: A computational investigation on mechanism, kinetic, and ecotoxicity
- Author
-
Hui, Zhao, Shuangjun, Wang, Yunju, Zhang, Chenggang, Lu, and Yizhen, Tang
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Abstract
Known organophosphorus pesticides are used widely in agriculture to improve the production of crops. Based on the literature, the degradation of some organophosphorus pesticides was studied theoretically. However, the mechanisms and variation of toxicity during the degradation of mevinphos and monocrotophos are still unclear in the environment, especially in wastewater. In this study, the reaction mechanisms for the degradation of the two representative organophosphorus pesticides (i.e., mevinphos and monocrotophos) in presence of OH radicals in the atmosphere and water are proposed using quantum chemical methods wB97-XD/6-311 + +G(3df,2pd)//wB97-XD/6-311 + +G(d,p). Result shows that the dominant channel is OH-addition to the C atom in CC bond with energy barriers being 15.6 and 14.7 kJ/mol, in the atmosphere and water, respectively, for mevinphos. As for monocrotophos, H-abstraction from NH group via barriers of 8.2 and 10.6 kJ/mol is more feasible in both the atmosphere and water. Moreover, the subsequent reactions of the major products in the atmosphere with NO and O
- Published
- 2023
- Full Text
- View/download PDF
17. Investigation on the adverse impacts of electrochemically produced ClOx- on assessing the treatment performance of dimensionally stable anode (DSA) for Cl−-containing wastewater
- Author
-
Wei Yan, Jinghua Chen, Jingli Wu, Yifan Li, Yijie Liu, Qipeng Yang, Yizhen Tang, and Bo Jiang
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,General Medicine ,General Chemistry ,Pollution - Published
- 2023
- Full Text
- View/download PDF
18. Optical coherence tomography analysis of anterior segment parameters before and after laser peripheral iridotomy in primary angle-closure suspects by using CASIA2
- Author
-
Xiaoxiao Chen, Xiaolei Wang, Yizhen Tang, Xinghuai Sun, and Yuhong Chen
- Subjects
Ophthalmology ,Iridectomy ,Anterior Eye Segment ,Lasers ,Gonioscopy ,Humans ,General Medicine ,Glaucoma, Angle-Closure ,Intraocular Pressure ,Tomography, Optical Coherence - Abstract
Background Laser peripheral iridotomy (LPI) is effective in primary angle-closure suspects (PACS); however, predictors for anterior segment alterations after LPI are limited. We aimed to evaluate the anterior segment biometric parameters before and after LPI in PACS using the recently developed, CASIA 2 device of anterior segment optical coherence tomography (AS-OCT). Methods We performed LPI in 52 PACS. Anterior segment parameters, including anterior chamber depth (ACD), anterior chamber width (ACW), anterior chamber volume (ACV), iris curvature (ICURVE), iridotrabecular contact (ITC), lens vault (LV), lens thickness (LT), radius of the lens, angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), and trabecular iris angle (TIA) at different distances (i.e., 500 μm from the sclera spur), were evaluated before and after LPI using CASIA 2. Results Eyes of PACS after LPI had a greater ACV, AOD, ARA, TISA, and TIA, and a lower ITC and ICURVE (all p p = 0.001, p = 0.010, p = 0.004, and p Conclusions We found that LPI widens the anterior chamber angle in the PACS, especially, in the superior quadrant around the iridotomy hole. Eyes with a thicker lens are more likely to experience angle opening because of the LPI.
- Published
- 2021
19. Synthesis, characterization and theoretical calculations of four chiral schiff base materials for second harmonic generation applications
- Author
-
Weiqiang Tan, Jiahui Gao, Jing Guan, Xuejun Bi, Yizhen Tang, Chunying Zheng, Tingliang Yan, and Chenglong Zhang
- Subjects
Inorganic Chemistry ,Organic Chemistry ,Spectroscopy ,Analytical Chemistry - Published
- 2022
- Full Text
- View/download PDF
20. Theoretical investigation on the gas phase reaction mechanism of methanol with Sn and Pb in sludge incineration
- Author
-
Shuangjun Wang, Hui Zhao, Chenggang Lu, and Yizhen Tang
- Subjects
Reaction mechanism ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Organic Chemistry ,Methanol ,Physical and Theoretical Chemistry ,Sludge incineration ,Gas phase - Published
- 2021
- Full Text
- View/download PDF
21. Atmospheric Chemistry of 2-Amino-2-methyl-1-propanol: A Theoretical and Experimental Study of the OH-Initiated Degradation under Simulated Atmospheric Conditions
- Author
-
Naomi J. Farren, Mattias Hallquist, Wen Tan, Barbara D'Anna, Jacqueline F. Hamilton, Simen Gjelseth Antonsen, Liang Zhu, Armin Wisthaler, Claus J. Nielsen, Markus Müller, Yizhen Tang, Tomas Mikoviny, Yngve Stenstrøm, Philipp Eichler, Jan B. C. Pettersson, University of Oslo (UiO), Leopold Franzens Universität Innsbruck - University of Innsbruck, Laboratoire Chimie de l'environnement (LCE), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), University of York [York, UK], University of Gothenburg (GU), and Norwegian University of Life Sciences (NMBU)
- Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Vapor pressure ,Radical ,Formaldehyde ,Hydrogen atom abstraction ,Quantum chemistry ,Article ,chemistry.chemical_compound ,chemistry ,[CHIM.ANAL]Chemical Sciences/Analytical chemistry ,Nitric acid ,Atmospheric chemistry ,Physical chemistry ,Physical and Theoretical Chemistry ,Acetamide - Abstract
International audience; The OH-initiated degradation of 2-amino-2-methyl-1-propanol [CH3C(NH2)(CH3)CH2OH, AMP] was investigated in a large atmospheric simulation chamber, employing time-resolved online high-resolution proton-transfer reaction-time-of-flight mass spectrometry (PTR-ToF-MS) and chemical analysis of aerosol online PTR-ToF-MS (CHARON-PTR-ToF-MS) instrumentation, and by theoretical calculations based on M06-2X/aug-cc-pVTZ quantum chemistry results and master equation modeling of the pivotal reaction steps. The quantum chemistry calculations reproduce the experimental rate coefficient of the AMP + OH reaction, aligning k(T) = 5.2 × 10–12 × exp (505/T) cm3 molecule–1 s–1 to the experimental value kexp,300K = 2.8 × 10–11 cm3 molecule–1 s–1. The theoretical calculations predict that the AMP + OH reaction proceeds via hydrogen abstraction from the −CH3 groups (5–10%), −CH2– group, (>70%) and −NH2 group (5–20%), whereas hydrogen abstraction from the −OH group can be disregarded under atmospheric conditions. A detailed mechanism for atmospheric AMP degradation was obtained as part of the theoretical study. The photo-oxidation experiments show 2-amino-2-methylpropanal [CH3C(NH2)(CH3)CHO] as the major gas-phase product and propan-2-imine [(CH3)2C═NH], 2-iminopropanol [(CH3)(CH2OH)C═NH], acetamide [CH3C(O)NH2], formaldehyde (CH2O), and nitramine 2-methyl-2-(nitroamino)-1-propanol [AMPNO2, CH3C(CH3)(NHNO2)CH2OH] as minor primary products; there is no experimental evidence of nitrosamine formation. The branching in the initial H abstraction by OH radicals was derived in analyses of the temporal gas-phase product profiles to be BCH3/BCH2/BNH2 = 6:70:24. Secondary photo-oxidation products and products resulting from particle and surface processing of the primary gas-phase products were also observed and quantified. All the photo-oxidation experiments were accompanied by extensive particle formation that was initiated by the reaction of AMP with nitric acid and that mainly consisted of this salt. Minor amounts of the gas-phase photo-oxidation products, including AMPNO2, were detected in the particles by CHARON-PTR-ToF-MS and GC×GC-NCD. Volatility measurements of laboratory-generated AMP nitrate nanoparticles gave ΔvapH = 80 ± 16 kJ mol–1 and an estimated vapor pressure of (1.3 ± 0.3) × 10–5 Pa at 298 K. The atmospheric chemistry of AMP is evaluated and a validated chemistry model for implementation in dispersion models is presented.
- Published
- 2021
- Full Text
- View/download PDF
22. Oxidative degradation of iodinated X-ray contrast media (iomeprol and iohexol) with sulfate radical: An experimental and theoretical study
- Author
-
Dongxue Xiao, Yaoguang Guo, Ying Huang, Dong Zhang, Jianshe Liu, Zhaohui Wang, Yizhen Tang, and Xiaoxiao Wang
- Subjects
Chemistry ,General Chemical Engineering ,Radical ,Iomeprol ,02 engineering and technology ,General Chemistry ,Primary alcohol ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Hydrogen atom abstraction ,01 natural sciences ,Medicinal chemistry ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,chemistry.chemical_compound ,Reaction rate constant ,Amide ,medicine ,Environmental Chemistry ,Iohexol ,0210 nano-technology ,Iodate ,medicine.drug - Abstract
It has already been known that oxidative degradation of organochlorine (e.g. chlorophenols) is accompanied by de novo formation of new polychlorinated compounds, however, whether the similar scenario can happen during decomposition of iodine-containing pollutants is completely unknown. Here degradation of two iodinated X-ray contrast media (ICM), iomeprol and iohexol, by sulfate radical generated through Co(II)-mediated activation of peroxymonosulfate (PMS) was investigated. The influencing parameters, such as the initial concentrations of PMS and Co(II), the initial solution pH and natural water constituents were examined. The pseudo-first-order rate constant of iomeprol in the PMS/Co(II) system is more than twice of iohexol, with values of 7.7 × 10−2 and 3.5 × 10−2 min−1, respectively, indicating that iomeprol seems more susceptible to radicals attack than iohexol. The bimolecular rate constants for reaction of sulfate radical (SO4•−) with ICM were determined to be 1.8 × 1010 M−1 s−1 and 7.9 × 109 M−1 s−1 for iomeprol and iohexol, respectively. The low degrees of mineralization and identification of iodinated intermediates of iomeprol and iohexol indicate that the degradation of iomeprol and iohexol in the Co/PMS system were incomplete. A de novo formation of new polyiodinated compounds would not happen because most of released inorganic iodine were ultimately oxidized to iodate (IO3−), rather than the reactive iodinated agents. Based on the identified byproducts and quantum chemical calculation, eight main transformation pathways are proposed for the degradation of iomeprol and iohexol as follows: (a) deiodination; (b) hydrogen abstraction; (c) amide hydrolysis; (d) amino oxidation; (e) hydroxyl substituent; (f) transformed alkyl aromatic amides to aromatic carbamoyl; (g) dehydration; (h) oxidized primary alcohol groups to carboxyl groups.
- Published
- 2019
- Full Text
- View/download PDF
23. A theoretical investigation on the degradation reactions of CH
- Author
-
Hui, Zhao, Chenggang, Lu, Yizhen, Tang, Yunju, Zhang, and Jingyu, Sun
- Subjects
Nitrosamines ,Photolysis ,Atmosphere ,Nitrogen Dioxide ,Animals ,Amines - Abstract
The degradation reactions of propylamino and dipropylamino radicals in the presence of NO, NO
- Published
- 2021
24. Atmospheric oxidation of 4‐( <scp>2‐methoxyethyl</scp> ) phenol initiated by <scp>OH</scp> radical in the presence of <scp> O 2 </scp> and <scp> NO x </scp> : A mechanistic and kinetic study
- Author
-
Yunju Zhang, Yanan Sun, Yizhen Tang, Wenzhong Wu, Jingyu Sun, and Junfang Yao
- Subjects
Reaction mechanism ,010304 chemical physics ,Kinetics ,Ketene ,010402 general chemistry ,Condensed Matter Physics ,Photochemistry ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,chemistry.chemical_compound ,Nitrophenol ,Reaction rate constant ,chemistry ,0103 physical sciences ,Phenol ,Density functional theory ,Physical and Theoretical Chemistry ,NOx - Abstract
4-(2-Methoxyethyl) phenol (MEP) is an significant methoxypheolic compound, which has been shown to play an important role in the formation of secondary organic aerosols(SOA). The present work focuses on the gas-phase oxidation mechanism and kinetics of MEP and OH radical by the density functional theory (DFT). Energetically favourable reaction channels and feasible products were identified. The initial reactions of MEP with OH radical have two different channels: OH addition and H abstraction. Subsequent reaction schemes of main intermediates in the presence of O2 and NOx are investigated using quantum chemical methods at M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level. Ketene, Phenyldiketones and nitrophenol compounds are demonstrated to be possible oxidation products. The total rate constant(1.69×10-11 cm3 molecule-1 s-1) and individual rate constant are calculated using the traditional transition state (TST) theory at 298K and 1atm. The lifetime of MEP is estimated to be 16.4 hours, which provides a comprehensive explanation for atmospheric oxidation pathway of MEP and shows MEP would be removed by OH radical in the atmosphere.
- Published
- 2021
- Full Text
- View/download PDF
25. CO2 Laser-Assisted Deep Sclerectomy Surgery Compared with Trabeculectomy in Primary Open-Angle Glaucoma: Two-Year Results
- Author
-
Xiaowei Yan, Guangxian Tang, Yizhen Tang, Yulei Geng, Fan Li, Hengli Zhang, and Lihua Ma
- Subjects
medicine.medical_specialty ,Intraocular pressure ,Visual acuity ,Open angle glaucoma ,Article Subject ,genetic structures ,medicine.medical_treatment ,Glaucoma ,Trab ,Deep sclerectomy ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Trabeculectomy ,Stage (cooking) ,business.industry ,RE1-994 ,medicine.disease ,eye diseases ,Surgery ,Ophthalmology ,030221 ophthalmology & optometry ,sense organs ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Purpose. To compare the effectiveness and safety of carbon dioxide (CO2) laser-assisted deep sclerectomy surgery (CLASS) and trabeculectomy (Trab) for treatment of primary open-angle glaucoma (POAG). Methods. In this retrospective and comparative study, 77 eyes of 62 patients with POAG were studied and divided into the CLASS and Trab groups. The best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of medications, surgical success rate, and complications were analyzed. Results. The mean follow-up periods were 27.89 ± 2.94 months and 26.11 ± 2.06 months in the CLASS and Trab groups, respectively. 30 eyes (24 patients) underwent CLASS and 47 eyes (38 patients) underwent Trab. The BCVA in the CLASS and Trab groups was recovered to baseline at postoperative 1 week and 1 month, respectively. At last follow-up visits, a remarkable reduction in the IOP and number of medications was observed in both groups, and no significant difference was found in those between the two groups. The complete success rates were 51.7% and 47.7% in postoperative 24 months in the CLASS and Trab groups, respectively ( P > 0.05 ). There were higher rates of delayed anterior chamber formation (21.3%) and thin-wall filtrating blebs (10.6%) in the Trab group. Meanwhile, the peripheral anterior synechiae were only observed in the CLASS group, and the ratio was 30%. Conclusions. CLASS is an effective and safe treatment modality for POAG, with fewer filtering bleb-related complications and quicker visual recovery in the early postoperative stage than trabeculectomy. The efficacy of lowering intraocular pressure was similar for both procedures.
- Published
- 2021
26. Atmospheric oxidation of 4-(2-Methoxyethyl) phenol initiated by OH radical in the presence of O2 and NOx: A mechanistic and kinetic study
- Author
-
Yanan Sun, Jingyu Sun, Yunju Zhang, Junfang Yao, Yizhen Tang, and Wenzhong Wu
- Subjects
chemistry.chemical_compound ,Nitrophenol ,Reaction rate constant ,chemistry ,Kinetics ,Ketene ,Phenol ,Density functional theory ,Photochemistry ,Kinetic energy ,NOx - Abstract
4-(2-Methoxyethyl) phenol (MEP) is an significant methoxypheolic compound, which has been shown to play an important role in the formation of secondary organic aerosols(SOA). The present work focuses on the gas-phase oxidation mechanism and kinetics of MEP and OH radical by the density functional theory (DFT). Energetically favourable reaction channels and feasible products were identified. The initial reactions of MEP with OH radical have two different channels: OH addition and H abstraction. Subsequent reaction schemes of main intermediates in the presence of O2 and NOx are investigated using quantum chemical methods at M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level. Ketene, Phenyldiketones and nitrophenol compounds are demonstrated to be possible oxidation products. The total rate constant(1.69×10-11 cm3 molecule-1 s-1) and individual rate constant are calculated using the traditional transition state (TST) theory at 298K and 1atm. The lifetime of MEP is estimated to be 16.4 hours, which provides a comprehensive explanation for atmospheric oxidation pathway of MEP and shows MEP would be removed by OH radical in the atmosphere.
- Published
- 2020
- Full Text
- View/download PDF
27. Reaction mechanisms and products of lead with C 6 H 6 and C 6 H 5 OH in incineration of sludge: A theoretical exploration
- Author
-
Hui Zhao, Zhuang Cheng, Yi Tong, Jingyu Sun, Yizhen Tang, and Chenggang Lu
- Subjects
Reaction mechanism ,Lead (geology) ,Chemistry ,Organic Chemistry ,Inorganic chemistry ,Physical and Theoretical Chemistry ,Incineration - Published
- 2020
- Full Text
- View/download PDF
28. Therapeutic Targeting of Retinal Immune Microenvironment With CSF-1 Receptor Antibody Promotes Visual Function Recovery After Ischemic Optic Neuropathy
- Author
-
Yizhen Tang, Zebin Xiao, Li Pan, Dongli Zhuang, Kin-Sang Cho, Kyle Robert, Xiaoxiao Chen, Lian Shu, Guangxian Tang, Jihong Wu, Xinghuai Sun, and Dong F. Chen
- Subjects
Male ,0301 basic medicine ,lcsh:Immunologic diseases. Allergy ,retinal ischemia/reperfusion ,visual acuity ,T cell ,Immunology ,microglia ,Receptor, Macrophage Colony-Stimulating Factor ,Retina ,Rats, Sprague-Dawley ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,medicine ,Animals ,Humans ,Immunology and Allergy ,Optic Neuropathy, Ischemic ,retinal ganglion cell ,Receptor ,positive scotopic threshold response ,Original Research ,Microglia ,business.industry ,neurodegeneration ,Retinal ,Recovery of Function ,medicine.disease ,colony stimulating factor-1 ,Antibodies, Neutralizing ,Rats ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Cellular Microenvironment ,chemistry ,Retinal ganglion cell ,business ,lcsh:RC581-607 ,Reperfusion injury ,030215 immunology - Abstract
Retinal ischemia/reperfusion injury (RI) is a common cause of irreversible visual impairment and blindness in elderly and critical unmet medical need. While no effective treatment is available for RI, microglial activation and local immune responses in the retina are thought to play important roles in the pathophysiology of neurodegeneration. While survival and activation of microglia depend critically on colony-stimulating factor receptor (CSF-1R) signaling, it remains unclear if targeting the retinal immune microenvironments by CSF-1RAb after RI is sufficient to rescue vision and present a potentially effective therapy. Here we used rodent models of RI and showed that retinal ischemia induced by acute elevation of intraocular pressure triggered an early activation of microglia and macrophages in the retina within 12 h. This was followed by lymphocyte infiltration and increased production of pro-inflammatory cytokines. Intravitreal injection of CSF-1R neutralizing antibody (CSF-1RAb) after RI significantly blocked microglial activation and the subsequent T cell recruitment. This also led to improved retinal ganglion cell survival and function measured by cell quantification and electroretinogram positive scotopic threshold responses, as well as increased visual acuity and contrast sensitivity as assessed by optomotor reflex-based assays, when compared to the isotype-treated control group. Moreover, the administration of CSF-1RAb efficiently attenuated inflammatory responses and activation of human microglia in culture, suggesting a therapeutic target with human relevance. These results, together with the existing clinical safety profiles, support that CSF-1RAb may present a promising therapeutic avenue for RI, a currently untreatable condition, by targeting microglia and the immune microenvironment in the retina to facilitate neural survival and visual function recovery.
- Published
- 2020
- Full Text
- View/download PDF
29. Metabolomic Profiling of Aqueous Humor and Plasma in Primary Open Angle Glaucoma Patients Points Towards Novel Diagnostic and Therapeutic Strategy
- Author
-
Yizhen Tang, Yiqiong Pan, Yuhong Chen, Xiangmei Kong, Junyi Chen, Hengli Zhang, Guangxian Tang, Jihong Wu, and Xinghuai Sun
- Subjects
0301 basic medicine ,Oncology ,medicine.medical_specialty ,Intraocular pressure ,Open angle glaucoma ,genetic structures ,Glaucoma ,Aqueous humor ,Retinal ganglion ,03 medical and health sciences ,0302 clinical medicine ,Metabolomics ,Internal medicine ,Medicine ,Pharmacology (medical) ,plasma ,Original Research ,mass spectrometry ,Pharmacology ,Receiver operating characteristic ,business.industry ,lcsh:RM1-950 ,medicine.disease ,metabolomics ,eye diseases ,primary open angle glaucoma ,030104 developmental biology ,lcsh:Therapeutics. Pharmacology ,030221 ophthalmology & optometry ,Biomarker (medicine) ,biomarker ,sense organs ,business ,aqueous humor - Abstract
Glaucoma is the second leading cause of blindness globally characterized by progressive loss of retinal ganglion cells (RGCs) and irreversible visual deficiency. As the most common type of glaucoma, primary open angle glaucoma (POAG) is currently an unmet medical need with limited therapy by lowering intraocular pressure (IOP). However, some patients continue to progress even though their IOP are controlled. Although early diagnosis and prompt treatment are crucial in preventing irreversible visual impairment, there are currently no biomarkers for screening POAG. Metabolomics has the advantages of illustrating the final downstream products of the genome and establishing the closest link to the phenotype. So far, there is no study investigating the metabolomic profiles in both aqueous humor and plasma of POAG patients. Therefore, to explore diagnostic biomarkers, unveil underlying pathophysiology and potential therapeutic strategies, a widely targeted metabolomic approach was applied using ultrahigh-resolution mass spectrometry with C18 liquid chromatography to characterize the metabolomic profiles in both aqueous humor and plasma of 28 POAG patients and 25 controls in our study. Partial least squares-discriminant analysis (PLS-DA) was performed to determine differentially expressed metabolites (DEMs) between POAG and age-matched controls. The area under the receiver operating characteristic curve (AUC) was calculated to assess the prediction accuracy of the DEMs. The correlation of DEMs with the clinical parameters was determined by Pearson correlation, and the metabolic pathways were analyzed using MetaboAnalyst 4.0. PLS-DA significantly separated POAG from controls with 22 DEMs in the aqueous humor and 11 DEMs in the plasma. Additionally, univariate ROC analysis and correlation analysis with clinical parameters revealed cyclic AMP (AUC = 0.87), 2-methylbenzoic acid (AUC = 0.75), 3′-sialyllactose (AUC = 0.73) in the aqueous humor and N-lac-phe (AUC = 0.76) in the plasma as potential biomarkers for POAG. Moreover, the metabolic profiles pointed towards the alteration in the purine metabolism pathway. In conclusion, the study identified potential and novel biomarkers for POAG by crosslinking the metabolomic profiles in aqueous humor and plasma and correlating with the clinical parameters. These findings have important clinical implications given that no biomarkers are currently available for glaucoma in the clinic, and the study provided new insights in exploring diagnostic biomarkers and potential therapeutic strategies of POAG by targeting metabolic pathways.
- Published
- 2020
30. CO
- Author
-
Hengli, Zhang, Yizhen, Tang, Xiaowei, Yan, Lihua, Ma, Yulei, Geng, Fan, Li, and Guangxian, Tang
- Subjects
genetic structures ,sense organs ,eye diseases ,Research Article - Abstract
Purpose To compare the effectiveness and safety of carbon dioxide (CO2) laser-assisted deep sclerectomy surgery (CLASS) and trabeculectomy (Trab) for treatment of primary open-angle glaucoma (POAG). Methods In this retrospective and comparative study, 77 eyes of 62 patients with POAG were studied and divided into the CLASS and Trab groups. The best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of medications, surgical success rate, and complications were analyzed. Results The mean follow-up periods were 27.89 ± 2.94 months and 26.11 ± 2.06 months in the CLASS and Trab groups, respectively. 30 eyes (24 patients) underwent CLASS and 47 eyes (38 patients) underwent Trab. The BCVA in the CLASS and Trab groups was recovered to baseline at postoperative 1 week and 1 month, respectively. At last follow-up visits, a remarkable reduction in the IOP and number of medications was observed in both groups, and no significant difference was found in those between the two groups. The complete success rates were 51.7% and 47.7% in postoperative 24 months in the CLASS and Trab groups, respectively (P > 0.05). There were higher rates of delayed anterior chamber formation (21.3%) and thin-wall filtrating blebs (10.6%) in the Trab group. Meanwhile, the peripheral anterior synechiae were only observed in the CLASS group, and the ratio was 30%. Conclusions CLASS is an effective and safe treatment modality for POAG, with fewer filtering bleb-related complications and quicker visual recovery in the early postoperative stage than trabeculectomy. The efficacy of lowering intraocular pressure was similar for both procedures.
- Published
- 2020
31. The role of commensal microflora-induced T cell responses in glaucoma neurodegeneration
- Author
-
Jing, Tang, Yizhen, Tang, Irvin, Yi, and Dong Feng, Chen
- Subjects
T-Lymphocytes ,Blood-Retinal Barrier ,Nerve Degeneration ,Animals ,Humans ,Glaucoma ,Heat-Shock Proteins ,Retina ,Gastrointestinal Microbiome - Abstract
Over the last decade, new evidence has become increasingly more compelling that commensal microflora profoundly influences the maturation and function of resident immune cells in host physiology. The concept of gut-retina axis is actively being explored. Studies have revealed a critical role of commensal microbes linked with neuronal stress, immune responses, and neurodegeneration in the retina. Microbial dysbiosis changes the blood-retina barrier permeability and modulates T cell-mediated autoimmunity to contribute to the pathogenesis of retinal diseases, such as glaucoma. Heat shock proteins (HSPs), which are evolutionarily conserved, are thought to function both as neuroprotectant and pathogenic antigens of T cells contributing to cell protection and tissue damage, respectively. Activated microglia recruit and interact with T cells during this process. Glaucoma, characterized by the progressive loss of retinal ganglion cells, is the leading cause of irreversible blindness. With nearly 70 million people suffering glaucoma worldwide, which doubles the number of patients with Alzheimer's disease, it represents the most frequent neurodegenerative disease of the central nervous system (CNS). Thus, understanding the mechanism of neurodegeneration in glaucoma and its association with the function of commensal microflora may help unveil the secrets of many neurodegenerative disorders in the CNS and develop novel therapeutic interventions.
- Published
- 2020
32. Morphologic Features of Crystalline Lens in Patients with Primary Angle Closure Disease Observed by CASIA 2 Optical Coherence Tomography
- Author
-
Xiaolei Wang, Yizhen Tang, Jiajian Wang, Xiaoxiao Chen, Xinghuai Sun, and Yuhong Chen
- Subjects
crystalline lens ,Male ,medicine.medical_specialty ,CASIA 2 ,Gonioscopy ,Microscopy, Acoustic ,Glaucoma ,Slit Lamp Microscopy ,Tonometry, Ocular ,Lens thickness ,Optical coherence tomography ,Anterior Eye Segment ,Ophthalmology ,Lens, Crystalline ,Medicine ,Humans ,In patient ,anterior segment optical coherence tomography ,Lens crystalline ,Intraocular Pressure ,Aged ,Related factors ,medicine.diagnostic_test ,business.industry ,Axial length ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Cross-Sectional Studies ,Lens (anatomy) ,Female ,business ,Glaucoma, Angle-Closure ,primary angle closure disease ,Tomography, Optical Coherence - Abstract
Purpose To investigate the morphologic features of crystalline lens in primary angle closure disease (PACD) by the swept-source anterior segment optical coherence tomography. Methods This cross-sectional observational study included 125 consecutive eyes from 125 patients who underwent anterior segment optical coherence tomography (CASIA 2, Tomey, Nagoya, Japan) examination, including 38 eyes of normal controls, 57 eyes of PAC suspects (PACS), and 30 eyes with PAC or PAC glaucoma (PACG). Crystalline lens parameters were compared among the three groups. Spearman correlation analysis and multiple linear regression models were performed to evaluate the relationships between the lens parameters and related factors. Results Significant differences were found for anterior chamber depth, axial length, iridotrabecular contact index, lens vault, lens thickness (all P < 0.001), the anterior radius curvature of lens (normal vs PACS vs PAC/PACG: 9.35 ± 1.29 mm vs 8.40 ± 0.62 mm vs 8.12 ± 0.54 mm; P < 0.001), lens decentration (normal vs PACS vs PAC/PACG: 0.14 ± 0.07 mm vs 0.19 ± 0.09 mm vs 0.22 ± 0.12 mm; P = 0.004), and tilt (normal vs PACS vs PAC/PACG: 4.9 ± 1.0° vs 5.3 ± 1.2° vs 5.8 ± 1.8°; P = 0.033) among the three groups. The multivariate regression analysis found that both iridotrabecular contact index and the stage of the PACD were negatively correlated with the anterior radius curvature of lens, positively correlated with lens thickness and decentration after adjustment for age, sex, and axial length (all P < 0.05). Conclusions Steep anterior curvature and decentration of the crystalline lens may be another anatomic characteristic of eyes with PACD. These findings support that the crystalline lens morphologic features may have great contribution to the development of PACD.
- Published
- 2020
33. Highly efficient and mild electrochemical degradation of bentazon by nano-diamond doped PbO
- Author
-
Yijie, Liu, Tong, Sun, Qing, Su, Yizhen, Tang, Xing, Xu, Muhammad, Akram, and Bo, Jiang
- Abstract
Anodic oxidation based on PbO
- Published
- 2020
34. The role of commensal microflora-induced T cell responses in glaucoma neurodegeneration
- Author
-
Yizhen Tang, Dong Feng Chen, Irvin Yi, and Jing Tang
- Subjects
Retina ,Microglia ,T cell ,Neurodegeneration ,Biology ,medicine.disease ,medicine.disease_cause ,Retinal ganglion ,Autoimmunity ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Immune system ,Heat shock protein ,Immunology ,medicine ,sense organs ,030217 neurology & neurosurgery - Abstract
Over the last decade, new evidence has become increasingly more compelling that commensal microflora profoundly influences the maturation and function of resident immune cells in host physiology. The concept of gut-retina axis is actively being explored. Studies have revealed a critical role of commensal microbes linked with neuronal stress, immune responses, and neurodegeneration in the retina. Microbial dysbiosis changes the blood-retina barrier permeability and modulates T cell-mediated autoimmunity to contribute to the pathogenesis of retinal diseases, such as glaucoma. Heat shock proteins (HSPs), which are evolutionarily conserved, are thought to function both as neuroprotectant and pathogenic antigens of T cells contributing to cell protection and tissue damage, respectively. Activated microglia recruit and interact with T cells during this process. Glaucoma, characterized by the progressive loss of retinal ganglion cells, is the leading cause of irreversible blindness. With nearly 70 million people suffering glaucoma worldwide, which doubles the number of patients with Alzheimer's disease, it represents the most frequent neurodegenerative disease of the central nervous system (CNS). Thus, understanding the mechanism of neurodegeneration in glaucoma and its association with the function of commensal microflora may help unveil the secrets of many neurodegenerative disorders in the CNS and develop novel therapeutic interventions.
- Published
- 2020
- Full Text
- View/download PDF
35. New theoretical investigation of mechanism, kinetics, and toxicity in the degradation of dimetridazole and ornidazole by hydroxyl radicals in aqueous phase
- Author
-
Yunju Zhang, Yizhen Tang, Jingyu Sun, Junfang Yao, Wenzhong Wu, and Min Ruan
- Subjects
Environmental Engineering ,Hydroxyl Radical ,Chemistry ,Health, Toxicology and Mutagenesis ,Radical ,Ornidazole ,Kinetics ,Water ,Pollution ,Dimetridazole ,Aquatic toxicology ,Adduct ,parasitic diseases ,medicine ,Water environment ,Environmental Chemistry ,Degradation (geology) ,Organic chemistry ,Oxidation-Reduction ,Waste Management and Disposal ,medicine.drug - Abstract
Dimetridazole (DMZ) and ornidazole (ONZ) have been widely used to treat anaerobic and protozoal infections. The residues of DMZ/ONZ persist in the water environment. The mechanisms and kinetics of hydroxyl-initiated oxidation, the primary DMZ/ONZ degradation method, were evaluated by quantum chemical methods.·OH-induced degradation of DMZ and ONZ shared many mechanistic and kinetic characteristics. The most feasible degradation pathway involved forming OH-imidazole adducts and NO2. The OH-imidazole adducts were subsequently degraded into double·OH imidazole intermediates. The rate coefficients for·OH degradation of DMZ and ONZ were 4.32 × 109 M−1 s−1 and 4.42 × 109 M−1 s−1 at 298 K, respectively. The lifetimes of DMZ and ONZ treated with·OH at concentrations of 10−9–10−18 mol L−1 at 298 K were τDMZ = 0.231–2.31 × 108 s and τONZ = 0.226–2.26 × 108 s, respectively. Toxicity assessment showed that the first degradation products of DMZ and ONZ exhibited enhanced aquatic toxicity, whereas most of the secondary degradation products were not harmful to aquatic organisms. Some of transformation products were still developmental toxicant or mutagenicity positive.
- Published
- 2022
- Full Text
- View/download PDF
36. A theoretical investigation on the degradation reactions of CH3CH2CH2NH and (CH3CH2CH2)2N radicals in the presence of NO, NO2 and O2
- Author
-
Hui Zhao, Yunju Zhang, Chenggang Lu, Yizhen Tang, and Jingyu Sun
- Subjects
Environmental Engineering ,biology ,Chemistry ,Health, Toxicology and Mutagenesis ,Radical ,Photodissociation ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Time-dependent density functional theory ,biology.organism_classification ,Photochemistry ,Pollution ,Daphnia ,Aquatic environment ,Environmental Chemistry ,Degradation (geology) ,%22">Fish ,Ecotoxicity - Abstract
The degradation reactions of propylamino and dipropylamino radicals in the presence of NO, NO2 and O2 were investigated at the CCSD(T)/6–311++G (2d, 2p)//B3LYP/6–311++G (d,p) levels of theory. Result indicates that nitrosamines, nitramines, nitroso-oxy compounds and imines can be formed at atmosphere. Time dependent density functional theory (TDDFT) calculation shows that nitrosamines and nitroso-oxy compounds can photolyze under sunlight, while nitramines cannot undergo photolysis in the daytime. Moreover, the ecotoxicity assessment result implies that the degradation of propyl-substituted amines by OH radicals, NO and NO2 will reduce their toxicity to fish, daphnia and green algae in the aquatic environment.
- Published
- 2022
- Full Text
- View/download PDF
37. Computational investigations on the HO2 + CHBr2O2 reaction: mechanisms, products, and atmospheric implications
- Author
-
Ying Gao, Youxiang Shao, Zhihao Fu, Yizhen Tang, Jingyu Sun, and Chenggang Lu
- Subjects
chemistry.chemical_classification ,Reaction mechanism ,Chemistry ,Health, Toxicology and Mutagenesis ,General Medicine ,010501 environmental sciences ,Photochemistry ,01 natural sciences ,Pollution ,Quantum chemistry ,Atmosphere ,Potential energy surface ,Halogen ,Environmental Chemistry ,Substitution effect ,Singlet state ,Alkyl ,0105 earth and related environmental sciences - Abstract
Using quantum chemistry methods, mechanisms and products of the CHBr2O2 + HO2 reaction in the atmosphere were investigated theoretically. Computational result indicates that the dominant product is CHBr2OOH + O2 formed on the triplet potential energy surface (PES). While CBr2O + OH + HO2 produced on the singlet PES is subdominant to the overall reaction under the typical atmospheric condition below 300 K. Due to higher energy barriers surmounted, other products including CBr2O2 + H2O2, CBr2O + HO3H, CH2O + HO3Br, CHBrO + HO3 + Br, and CHBr2OH + O3 make minor contributions to the overall reaction. In the presence of OH radical, CHBr2OOH generates CHBr2O2 and CBr2O2 + H2O subsequently, which enters into new Br-cycle in the atmosphere. The substitution effect of alkyl group and halogens plays negligible roles to the dominant products in the RO2 + HO2 (X = H, CH3, CH2OH, CH2F, CH2Cl, CH2Br, CH2Cl, and CH2Br) reactions in the atmosphere.
- Published
- 2018
- Full Text
- View/download PDF
38. Mechanistic and kinetic study on the reaction of Pyrrole (C4H5N) with O(3P)
- Author
-
Yu-Xi Sun, Yunju Zhang, Rongshun Wang, Yizhen Tang, Jingyu Sun, and Ruojing Song
- Subjects
chemistry.chemical_classification ,Reaction mechanism ,010304 chemical physics ,Double bond ,General Physics and Astronomy ,010402 general chemistry ,Branching (polymer chemistry) ,Kinetic energy ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Reaction rate constant ,chemistry ,0103 physical sciences ,Atomic oxygen ,Physical chemistry ,Singlet state ,Physical and Theoretical Chemistry ,Pyrrole - Abstract
The mechanism and kinetic for the reaction of Pyrrole + O(3P) has been investigated using CCSD(T)//M06-2X method with multichannel RRKM-TST calculation. On the triplet surface, four product channels corresponding to α-C-addition, β-C-addition, N-addition and direct H-abstraction have been characterized for the first time. The rate constants and branching ratios for twelve product channels are calculated. It is predicted that the total rate coefficients vary with temperature, and exhibit strong positive temperature dependence. Moreover, the total rate coefficients are independence pressure. On the singlet surface, the atomic oxygen can easily add to the C C double bond or the N atom of Pyrrole forming intermediate s-IM1or s-IM2; both approaches were found to be barrierless. It is indicated that the singlet reaction exhibits a marked difference from the triplet reaction. This calculation is useful to simulate experimental investigations of the Pyrrole + O reaction in the singlet surface.
- Published
- 2018
- Full Text
- View/download PDF
39. Theoretical investigations on the atmospheric C 2 H 5 O 2 + ClO reaction
- Author
-
Yunju Zhang, Lu Chenggang, Dawei Li, Jing Feng, Yizhen Tang, Jingyu Sun, and Lv Mou
- Subjects
010304 chemical physics ,Chemistry ,Time-dependent density functional theory ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Potential energy ,Quantum chemistry ,0104 chemical sciences ,Atmosphere ,0103 physical sciences ,Physical chemistry ,Density functional theory ,Singlet state ,Physical and Theoretical Chemistry ,Excitation - Abstract
Mechanisms and channels of the C2H5O2 + ClO reaction in atmosphere were investigated using quantum chemistry method, i.e., CCSD(T)/6-311++G(2d,2p)//B3LYP/6-311++G(d,p) levels of theory. Our result indicates that the title reaction occurs on both the singlet and triplet potential energy surfaces (PESs). Kinetically, C2H5O3Cl and C2H5O + ClOO on the singlet PES were dominant in atmosphere; while other products including CH3CHO2 + HOCl, CH3CHO + HOClO, and CH3CHO + HClO2 make minor contributions to overall reaction due to high barriers and unstable formations. Moreover, time-dependent density functional theory (TDDFT) calculation on the vertical excitation energy implies that C2H5O3Cl will photolyze under the sunlight.
- Published
- 2018
- Full Text
- View/download PDF
40. Quantum chemical study of the mechanisms, kinetics, and ecotoxicity assessment of OH radical-initiated reactions of 2,2′,4,4′,5,5′ -hexabrominated diphenyl ether (BDE-153) in atmosphere and wastewater
- Author
-
Yunju Zhang, Wenzhong Wu, Jingyu Sun, Min Ruan, Fang Chen, Junfang Yao, and Yizhen Tang
- Subjects
General Chemical Engineering ,Diphenyl ether ,Kinetics ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Redox ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Chemical kinetics ,chemistry.chemical_compound ,Reaction rate constant ,chemistry ,Computational chemistry ,Solvent models ,Environmental Chemistry ,Solvent effects ,Ecotoxicity ,0210 nano-technology - Abstract
2,2′,4,4′,5,5′-hexabrominated diphenyl ether (BDE-153) and its OH radical addition products are considered potentially harmful to ecological systems. Therefore, the oxidation reactions mechanisms of BDE-153 initiated by OH radical, the reaction kinetics and the ecotoxicity of BDE-153 assessment in the gas and the aqueous phase were investigated using quantum chemical methods. It is more feasible for the OH radical to add at the nonbromine substituted carbon atoms of the aromatic ring in the BDE-153 molecule to create OH addition intermediates. The secondary reactions involving OH addition intermediates in the presence of O2/NO would generate preferred tribromophenol and OH-addition products. Most of the transformation products are still toxic to aquatic organisms. The total and individual rate constants were evaluated by using the KiSThelP program in a suitable temperature range (198–338 K) and a pressure of 1 atm. At 298 K and 1 atm, the total rate constants in atmosphere and wastewater are 2.90 × 10-13 cm3 molecule-1 s−1 and 9.61 × 106 M−1 s−1, and the half-lives are 39.9 days and 72.1–7.21 × 1010 s, respectively. The implicit and explicit solvent models were used to examine the solvent effect on the total reaction. These results clarify the transformation mechanism, atmospheric fate, and ecotoxicity of BDE-153 in advanced oxidation processes. The calculations provided a basis for designing experimental and industrial applications of BDE-153.
- Published
- 2021
- Full Text
- View/download PDF
41. TaWRKY10 plays a key role in the upstream of circadian gene TaLHY in wheat
- Author
-
Yizhen Tang, Zhongyuan Li, Liqiang Zhang, Jiahe Wen, Zhiming Wang, Huaiyu Zhang, Chaoyang Zhu, Yang-Er Chen, and Yongying Su
- Subjects
0106 biological sciences ,0301 basic medicine ,Regulator ,Plant Science ,Biology ,01 natural sciences ,03 medical and health sciences ,Downregulation and upregulation ,Genetics ,Gene silencing ,MYB ,Transcription factor ,Gene ,Triticum ,Disease Resistance ,Plant Diseases ,Plant Proteins ,Basidiomycota ,food and beverages ,Promoter ,General Medicine ,WRKY protein domain ,Cell biology ,030104 developmental biology ,Agronomy and Crop Science ,Transcription Factors ,010606 plant biology & botany - Abstract
TaLHY is an MYB transcription factor (TF) that is upregulated by salicylic acid induction and shows circadian rhythms. However, the study of the upstream regulatory factors is still unclear. In this study, we cloned the promoter sequence of the TaLHY homologous genes, verified the activity of the promoters, and identified important regions that affect promoter activity. Furthermore, we explored a possible upstream regulator of TaLHY, named TaWRKY10, which played a key role in the expression of TaLHY. We found that the three promoters pTaLHYa, pTaLHYb, and pTaLHYd had transcriptional activity in wheat protoplasts. All three promoters have W-Box, which can bind to WRKY TFs. Using virus-induced gene silencing (VIGS), after silencing TaWRKY10, the resistance of ChuanNong 19 (CN19) to stripe rust pathogen strain CYR32 was lost, and the expression level of the TaLHY homologous gene decreased. At the same time, in wheat protoplasts, the transcriptional activity of TaLHY homologous promoters improved after TaWRKY10 overexpression. This indicates that TaWRKY10 is a key gene for wheat immune response to stripe rust, and this gene may bind to TaLHYa, TaLHYb, and TaLHYd promoters to regulate the expression of TaLHY.
- Published
- 2021
- Full Text
- View/download PDF
42. Mechanistic and kinetic study on the reaction of methylperoxyl radical with atomic hydrogen
- Author
-
Yunju Zhang, Yizhen Tang, Rongshun Wang, Jingyu Sun, Ruojing Song, Yuxi Sun, and Yongguo Liu
- Subjects
Reaction mechanism ,010304 chemical physics ,Hydrogen ,Chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Atmospheric temperature range ,010402 general chemistry ,Kinetic energy ,Photochemistry ,01 natural sciences ,Potential energy ,0104 chemical sciences ,Reaction rate constant ,Computational chemistry ,0103 physical sciences ,Singlet state ,Physical and Theoretical Chemistry - Abstract
Singlet and triplet potential energy surfaces for the CH3O2 with H reaction have been investigated computationally to propose the reaction mechanisms and possible products. On the singlet PES, addition-dissociation was located. At 3.65 Torr with He as bath gas, the formation of CH2O + H2O channel is dominated at the whole temperature range. Furthermore, the predicted rate constants for k CH 2 O + H 2 O at 298 K 3.65 Torr of He agree well with the available experimental values. The pathways on the triplet PES will not compete with the pathways on the singlet PES in kinetically.
- Published
- 2017
- Full Text
- View/download PDF
43. Clinical evaluation of corneal changes after phacoemulsification in diabetic and non-diabetic cataract patients, a systematic review and meta-analysis
- Author
-
Xinyi Chen, Ke Yao, Xiaobo Zhang, Siyu Liu, Yizhen Tang, and Qiaomei Tang
- Subjects
Corneal endothelium ,medicine.medical_specialty ,genetic structures ,medicine.medical_treatment ,lcsh:Medicine ,030209 endocrinology & metabolism ,Cataract ,Article ,Cornea ,Diabetes Complications ,03 medical and health sciences ,0302 clinical medicine ,Ophthalmology ,medicine ,Humans ,Prospective cohort study ,lcsh:Science ,Multidisciplinary ,business.industry ,lcsh:R ,Phacoemulsification ,Confidence interval ,eye diseases ,medicine.anatomical_structure ,Meta-analysis ,030221 ophthalmology & optometry ,Emulsions ,lcsh:Q ,sense organs ,business ,Clinical evaluation ,Non diabetic - Abstract
Corneal endothelium morphological abnormalities result in fluid imbalance, stromal swelling, and loss of transparency, thus impairing visual function. Recently, growing number of studies have focused on diabetic corneal abnormalities after cataract surgery and its comparison with non-diabetic patients, the results remain conflicting. Thus, to evaluate the effect of phacoemulsification on the corneal properties in diabetic and non-diabetic patients, prospective studies were comprehensively searched through PubMed, EMBASE, and Cochrane databases updated to Jan 2017. A meta-analysis of the 13 identified studies was performed using weighted mean difference (WMD) and 95% confidence interval (CI). For the dynamic changes between preoperative and postoperative values, significant differences were identified between the two groups in endothelial cell density (ECD) and hexagon cells (HC%) at 1 day, 1 week, 1 month, and 3 months postoperatively, in central corneal thickness (CCT) at 1 month postoperatively, and in coefficient variation (CV) at 1 week and 1 month postoperatively. However, no significant differences were observed in CCT at 1 day, 1 week and 3 months postoperatively or in CV at 1 day and 3 months postoperatively. Diabetic corneas are more vulnerable to stress and trauma, resulting in greater morphological abnormalities and longer recovery time.
- Published
- 2017
- Full Text
- View/download PDF
44. Theoretical investigation of the selective dehydration and dehydrogenation of ethanol catalyzed by small molecules
- Author
-
Yanqun Wang, Youxiang Shao, and Yizhen Tang
- Subjects
Models, Molecular ,inorganic chemicals ,Formic acid ,Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Materials Chemistry ,medicine ,Organic chemistry ,Dehydrogenation ,Dehydration ,Physical and Theoretical Chemistry ,Spectroscopy ,Ethanol ,Water ,Models, Theoretical ,021001 nanoscience & nanotechnology ,medicine.disease ,Hydrogen fluoride ,Computer Graphics and Computer-Aided Design ,Supercritical fluid ,0104 chemical sciences ,Solvent ,Kinetics ,chemistry ,0210 nano-technology ,Oxidation-Reduction ,Algorithms ,Hydrogen - Abstract
Catalytic dehydration and dehydrogenation reactions of ethanol have been investigated systematically using the ab initio quantum chemistry methods The catalysts include water, hydrogen peroxide, formic acid, phosphoric acid, hydrogen fluoride, ammonia, and ethanol itself. Moreover, a few clusters of water and ethanol were considered to simulate the catalytic mechanisms in supercritical water and supercritical ethanol. The barriers for both dehydration and dehydrogenation can be reduced significantly in the presence of the catalysts. It is revealed that the selectivity of the catalytic dehydration and dehydrogenation depends on the acidity and basicity of the catalysts and the sizes of the clusters. The acidic catalyst prefers dehydration while the basic catalysts tend to promote dehydrogenation more effectively. The calculated water-dimer catalysis mechanism supports the experimental results of the selective oxidation of ethanol in the supercritical water. It is suggested that the solvent- and catalyst-free self-oxidation of the supercritical ethanol could be an important mechanism for the selective dehydrogenation of ethanol on the theoretical point of view.
- Published
- 2017
- Full Text
- View/download PDF
45. Halogen Bonding in the Complexes of CH3I and CCl4 with Oxygen-Containing Halogen-Bond Acceptors
- Author
-
Peiwen Wang, Yizhen Tang, and Nan Zhao
- Subjects
inorganic chemicals ,Halogen bond ,Matrix isolation ,Infrared spectroscopy ,Ether ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Halogen ,Acetone ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology ,Tetrahydrofuran - Abstract
Methyl iodine (CH3I) and carbon tetrachloride (CCl4) are both important volatile precursors for atmospheric ozone destruction. CH3I and CCl4 can act as halogen bond donors to form molecular complexes with atmospheric organic species, such as 2,5-dihydrofuran, tetrahydrofuran, and acetone. This study characterized the halogen bonds in the CH3I and CCl4 complexes using matrix isolation infrared spectroscopy and density functional theory calculations. With the combination of vibrational frequencies in spectra and the calculated interaction energies, frequencies and atoms-in-molecules analyses, we confirmed the formation of halogen-bonded complexes. CH3I as a halogen-bond donor is comparable or slightly weaker than CCl4, and furans involving ether oxygens are better halogen acceptors than acetone. The results help to understand the possibilities of formation of atmospheric molecular complexes that may influence the atmospheric chemical activities and enhance the aerosol formation.
- Published
- 2017
- Full Text
- View/download PDF
46. Theoretical investigation on the reaction of Methylidyne Radical (CH) with acetaldehyde (CH 3 CHO)
- Author
-
Youxiang Shao, Yizhen Tang, and Yanqun Wang
- Subjects
Exothermic reaction ,Reaction mechanism ,010304 chemical physics ,Hydrogen ,Chemistry ,Acrolein ,Acetaldehyde ,chemistry.chemical_element ,010402 general chemistry ,Condensed Matter Physics ,Photochemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,0104 chemical sciences ,chemistry.chemical_compound ,Methylidyne radical ,0103 physical sciences ,Physical and Theoretical Chemistry - Abstract
The mechanism of the reaction of Methylidyne Radical (CH) with acetaldehyde (CH 3 CHO) has been investigated using CBS-QB3//B3LYP/aug-cc-pVTZ method. The initial CH + CH 3 CHO reaction is a barrierless process, forming a linear intermediate, CH 3 CHOCH, which can be converted into several products. The microscopic mechanism recommended by the present study not only identifies the products observed by previous experimental studies but also explains the isotopic effects (CH/CCD) observed experimentally. In view of the calculated energies, C 2 H 5 + CO is the most exothermic product pair, additionally, the energy barrier of this product channel is the lowest. Concerning the hydrogen elimination channel, acrolein (CH 2 CHCHO) and methylketene (CH 3 CHCO) are preferable co-products. Furthermore, a new product channel, C 2 H 3 + CH 2 O, has been discovered.
- Published
- 2017
- Full Text
- View/download PDF
47. The mechanistic and kinetic investigation on the atmospheric reaction of atomic O(3P) with crotononitrile
- Author
-
Youxiang Shao, Jiangyan Liu, Weidong Wang, Wenzhong Wu, Da Zhou, Yinfang Cheng, Fang Chen, Yizhen Tang, Jingyu Sun, Yunhang Yin, and Juan Wang
- Subjects
RRKM theory ,010304 chemical physics ,Chemistry ,010402 general chemistry ,Condensed Matter Physics ,Kinetic energy ,01 natural sciences ,Biochemistry ,Potential energy ,0104 chemical sciences ,Reaction rate constant ,Yield (chemistry) ,0103 physical sciences ,Atom ,Potential energy surface ,Physical chemistry ,Singlet state ,Physical and Theoretical Chemistry - Abstract
The mechanism and kinetics for the O( 3 P) + CH 3 CH CHCN reaction has been investigated firstly. The BHandHLYP and M05-2X methods were employed to obtain the initial geometries. The triplet/singlet potential energy surfaces (PESs) were constructed with high-level BMC-CCSD method. The conventional transition-state theory (CTST) and multichannel RRKM theory were employed to calculate the total and individual rate constants over a wide range of temperatures under high-pressure limit. Our computed rates agree well with the available experimental results. The yield of IM1 is 0.9–0.5 from 200 to 1000 K, and the construction of h-P1(OH + CH 2 CHCHCN) is 0.42 at 2000 K under high-pressure limit. The yields of the predicted decomposition products P1(CH 3 + HCOHCCN), P2(HCCN + CH 3 CHO) and P3(H + CH 3 COHCCN) at 298 K and 1 atom are 0.81, 0.07, and 0.09, respectively.
- Published
- 2017
- Full Text
- View/download PDF
48. Theoretical investigations on mechanisms and kinetics of CH
- Author
-
Yunju, Zhang, Yizhen, Tang, Jingyu, Sun, and Bing, He
- Abstract
The reactions of the CH
- Published
- 2019
49. Computational study on the mechanisms and kinetics of the CH
- Author
-
Yunju, Zhang, Yizhen, Tang, and Bing, He
- Abstract
The singlet and triplet potential energy surfaces for the CH
- Published
- 2019
50. A theoretical study on gas-phase reactions of acrylic acid with chlorine atoms: mechanism, kinetics, and insights
- Author
-
Han Chu, Fang Chen, Yanan Sun, Jiangyan Liu, Jingyu Sun, Youxiang Shao, Yizhen Tang, and Wenzhong Wu
- Subjects
Chemistry ,Atmosphere ,Health, Toxicology and Mutagenesis ,Kinetics ,General Medicine ,010501 environmental sciences ,Photochemistry ,Hydrogen atom abstraction ,01 natural sciences ,Pollution ,Redox ,Potential energy ,Reaction coordinate ,chemistry.chemical_compound ,Reaction rate constant ,Acrylates ,Environmental Chemistry ,Negative temperature ,Chlorine ,0105 earth and related environmental sciences ,Acrylic acid - Abstract
Chlorine atoms initiated oxidation reactions are significant for the removal of typical volatile organic compounds (VOCs) in the atmosphere. The intrinsic mechanisms of CH2=CHCOOH + Cl reaction have been carried out at the CCSD(T)/cc-pVTZ//M06-2X/6-311++G(d,p) level. There are hydrogen abstraction and C-addition pathways on potential energy surfaces. By analyses, the addition intermediates of IM1(ClCH2CHCOOH) and IM2(CH2CHClCOOH) are found to be dominant. The secondary reactions of IM1 and IM2 have been discussed in the presence of O3, O2, NO, and NO2. And we have also investigated the degradation mechanisms of ClCH2CHO2COOH with NO, NO2, and self-reaction. Moreover, the atmospheric kinetics has been calculated by the variable reaction coordinate transition-state theory (VRC-TST). As a result, the rate constants show negative temperature and positive pressure dependence. The atmospheric lifetime and global warming potentials of acrylic acid have been calculated. Overall, the current study elucidates a new mechanism for the atmospheric reaction of chlorine atoms with acrylic acid.
- Published
- 2019
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.