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二氢杨梅素分子结构与性质的密度泛函理论研究

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原子与分子物理学报 2025年第1期42卷 29-34页

作者：辛国鹏毛敏刘信平马文涛马杰张煜湖北民族大学化学与环境工程学院恩施445000

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H... 详细信息

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H23)附近;而亲电活性位点位于氧原子(O32)及其附近.前线分子轨道研究结果表明二氢杨梅素分子的最高占据轨道(HOMO)都位于酮基氧(O32)和羟基氧(O20)附近,说明这些位点易与亲电试剂反应.而最低空轨道(LUMO)位于碳原子(C12、C13、C14)区域,表明这些区域可与亲核试剂反应.简缩福井函数(f)结果证实了位于C-O-C键中的氧原子的f-值的亲电活性较其他位点氧原子大;而位于C8碳原子的f^(+)值较大,因此该位点亲核活性较强.通过理论计算所得到的二氢杨梅素的红外光谱数据与实验所得到的红外光谱数据相差不大,这就说明理论计算结果是较为可靠的.从而为实验和理论研究二氢杨梅素结构与性质的关系提供了一定的理论参考.

关键词：二氢杨梅素密度泛函理论反应活性位点量子化学计算

Conservative and functional surgery in the treatment of salivary gland tumours

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International Journal of Oral Science 2019年第3期11卷 176-179页

作者： Guangyan Yu xin peng Department of Oral & Maxillofacial Surgery Peking University School and Hospital of Stomatology

The principle of modern oncological surgery is to conserve the functional organs or tissues as much as possible based on eradication of the *** salivary gland tumours,conservative and functional salivary surgery,including partial sialoadenectomy as well as anatomical and functional preservation of the facial nerve,great auricular nerve,superficial musculoaponeurotic system (SMAS),and Stensen’s duct,has become increasingly *** the present review,we discuss the following aspects of conservative and functional surgery in the treatment of salivary gland tumours:(i) partial superficial parotidectomy (PP) to treat benign parotid gland tumours,(ii) modification of surgical incisions to improve cosmetic results,(iii) modification of the surgical approach to decrease complications,(iv) extracardial dissection to treat benign superficial parotid tumours,(v) partial sialoadenectomy to treat benign submandibular gland tumours,and (vi) 125I brachytherapy to preserve facial *** majority of the operated parotid or submandibular glands are preserved,and surgical complications are also *** and functional surgery plays a significant role in maintaining normal salivary gland function and in improving patients’ quality of life during the treatment of salivary gland tumours and thus should be further promoted.

关键词： salivary gland great auricular nerve parotid gland

A Method to Construct the Nonlocal Symmetries of Nonlinear Evolution Equations

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Chinese Physics Letters 2013年第10期30卷 5-8页

作者： xin Xiang-peng CHEN Yong Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai 200062

A method is proposed to seek the nonlocal symmetries of nonlinear evolution *** validity and advantages of the proposed method are illustrated by the applications to the Boussinesq equation,the coupled Korteweg-de Vries system,the Kadomtsev–Petviashvili equation,the Ablowitz–Kaup–Newell–Segur equation and the potential Korteweg-de Vries *** facts show that this method can obtain not only the nonlocal symmetries but also the general Lie point symmetries of the given equations.

关键词： equations equation equation

Classic axon guidance molecules control correct nerve bridge tissue formation and precise axon regeneration

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Neural Regeneration Research 2020年第1期15卷 6-9页

作者： xin-peng Dun David BParkinson Faculty of Medicine and Dentistry Plymouth UniversityPlymouthDevonUK The Co-Innovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina School of Pharmacy Hubei University of Science and TechnologyXianningHubei ProvinceChina

The peripheral nervous system has an astonishing ability to regenerate following a compression or crush injury;however,the potential for full repair following a transection injury is much ***,the major clinical challenge for peripheral nerve repair come from long gaps between the proximal and distal nerve stumps,which prevent regenerating axons reaching the distal *** axon targeting during nervous system development is controlled by families of axon guidance molecules including Netrins,Slits,Ephrins and *** recent studies have indicated key roles of Netrin1,Slit3 and EphrinB2 signalling in controlling the formation of new nerve bridge tissue and precise axon regeneration after peripheral nerve transection *** the nerve bridge,nerve fibroblasts express EphrinB2 while migrating Schwann cells express the receptor ***2/EphB2 signalling between nerve fibroblasts and migrating Schwann cells is required for Sox2 upregulation in Schwann cells and the formation of Schwann cell cords within the nerve bridge to allow directional axon growth to the distal nerve *** in the outermost layer of the nerve bridge express Slit3 while migrating Schwann cells and regenerating axons express the receptor Robo1;within Schwann cells,Robo1 expression is also ***3/Robo1 signalling is required to keep migrating Schwann cells and regenerating axons inside the nerve *** addition to the Slit3/Robo1 signalling system,migrating Schwann cells also express Netrin1 and regenerating axons express the DCC *** appears that migrating Schwann cells could also use Netrin1 as a guidance cue to direct regenerating axons across the peripheral nerve *** neural tissues have been suggested as promising alternatives for the repair of large peripheral nerve ***,understanding the function of classic axon guidance molecules in nerve bridge formation and their roles in axon regeneration could be h

关键词： axonal guidance EphrinB2 nerve bridge Netrin1 peripheral nerve regeneration Slit3 Sox2 transection injury

Speed Distributions of CMEs in Cycle 23 at Low and High Latitudes

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Chinese Journal of Astronomy and Astrophysics 2008年第2期8卷 146-152页

作者： peng-xin Gao Ke-Jun Li National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 GraduateSchool of Chinese Academy of Sciences Beijing 100049

We analyzed the speed （v） distributions of 11584 coronal mass ejections （CMEs） observed by the Large Angle and Spectrometric Coronagraph Experiment on board the Solar and Heliospheric Observatory （SOHO/LASCO） in cycle 23 from 1996 to 2006. We find that the speed distributions for high-latitude （HL） and low-latitude （LL） CME events are nearly identical and to a good approximation they can be fitted with a lognormal distribution. This finding implies that statistically the same driving mechanism of a nonlinear nature is acting in both HL and LL CME events, and CMEs are intrinsically associated with the source＇s magnetic structure on large spatial scales. Statistically, the HL CMEs are slightly slower than the LL CMEs. For HL and LL CME events respectively, the speed distributions for accelerating and decelerating events are nearly identical and also to a good approximation they can be both fitted with a lognormal distribution, thus supplementing the results obtained by Yurchyshyn et al.

关键词： Sun activity -- Sun coronal mass ejections (CMEs)

Dynamic expression of Slit1–3 and Robo1–2 in the mouse peripheral nervous system after injury

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Neural Regeneration Research 2020年第5期15卷 948-958页

作者： Bing Chen Lauren Carr xin-peng Dun Department of Neurology The Affiliated Huaian No.1 People’s Hospital of Nanjing Medical UniversityHuai’anJiangsu ProvinceChina Plymouth University Peninsula Schools of Medicine and Dentistry PlymouthUK The Co-innovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina

The Slit family of axon guidance cues act as repulsive molecules for precise axon pathfinding and neuronal migration during nervous system development through interactions with specific Robo *** we previously reported that Slit1–3 and their receptors Robo1 and Robo2 are highly expressed in the adult mouse peripheral nervous system,how this expression changes after injury has not been well ***,we constructed a peripheral nerve injury mouse model by transecting the right sciatic *** 14 days after injury,quantitative real-time polymerase chain reaction was used to detect mRNA expression of Slit1–3 and Robo1–2 in L4–5 spinal cord and dorsal root ganglia,as well as the sciatic *** analysis was performed to examine Slit1–3,Robo1–2,neurofilament heavy chain,F4/80,and vimentin in L4–5 spinal cord,L4 dorsal root ganglia,and the sciatic ***-expression of Slit1–3 and Robo1–2 in L4 dorsal root ganglia was detected by in situ *** addition,Slit1–3 and Robo1–2 protein expression in L4–5 spinal cord,L4 dorsal root ganglia,and sciatic nerve were detected by western blot *** results showed no significant changes of Slit1–3 or Robo1–2 mRNA expression in the spinal cord within 14 days after *** the dorsal root ganglion,Slit1–3 and Robo1–2 mRNA expression were initially downregulated within 4 days after injury;however,Robo1–2 mRNA expression returned to the control level,while Slit1–3 mRNA expression remained upregulated during regeneration from 4–14 days after *** the sciatic nerve,Slit1–3 and their receptors Robo1–2 were all expressed in the proximal nerve stump;however,Slit1,Slit2,and Robo2 were barely detectable in the nerve bridge and distal nerve stump within 14 days after ***3 was highly ex-pressed in macrophages surrounding the nerve bridge and slightly downregulated in the distal nerve stump within 14 days after ***1 was upregulated in vimentin-positive cells and migrating S

关键词： dorsal root ganglion nerve regeneration neural regeneration peripheral nerve Robo 1 Robo 2 sciatic nerve Slit1 Slit2 Slit3

Performance monitoring of non-gaussian chemical processes with modes-switching using globality-locality preserving projection

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Frontiers of Chemical Science and Engineering 2017年第3期11卷 429-439页

作者： xin peng Yang Tang Wenli Du Feng Qian Key Laboratory of Advanced Control and Optimization for Chemical Process Ministry of Education East China University of Science and Technology Shanghai 200237 China

In this paper, we propose a novel performance monitoring and fault detection method, which is based on modified structure analysis and globality and locality preserving （MSAGL） projection, for non-Gaussian processes with multiple operation conditions. By using locality preserving projection to analyze the embedding geometrical manifold and extracting the non-Gaussian features by independent component analysis, MSAGL preserves both the global and local structures of the data simultaneously. Furthermore, the tradeoff parameter of MSAGL is tuned adaptively in order to find the projection direction optimal for revealing the hidden structural information. The validity and effectiveness of this approach are illustrated by applying the proposed technique to the Tennessee Eastman process simulation under multiple operation conditions. The results demonstrate the advantages of the proposed method over conventional eigendecomposition-based monitoring methotis.

关键词： non-Gaussian processes subspace projection independent component analysis locality preserving projection finite mixture model

Non-thermal effects of 0.1 THz radiation on intestinal alkaline phosphatase activity and conformation

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Chinese Physics B 2019年第12期28卷 383-388页

作者： xin-xin Zhang Ming-Xia He Yu Chen Cheng Li Jin-Wu Zhao peng-Fei Wang xin peng The Center for Terahertz Waves School of Precision Instrument and Opto-electronics EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China Department of Chemistry School of ScienceTianjin UniversityTianjin 300354China School of Life Sciences Tianjin UniversityTianjin 300072China

Alkaline phosphatase(ALP) plays an integral role in the metabolism of liver and development of the skeleton in humans. To date, the interactions between different-duration terahertz(THz) radiation and ALP activities, as well as the influence mechanism are still unclear. In this study, using the para-nitro-phenyl-phosphate(p NPP) method, we detect changes in ALP activities during 40-minute THz radiation(0.1 THz, 13 m W/cm^2). It is found that the activity of ALP decreases in the first 25 min, and subsequently increases in the later 15 min. Compared with the activity of ALP being heated, the results suggest that short-term terahertz radiation induces a decrease in enzyme activity through the non-thermal mechanism. In order to explore the non-thermal effects of THz radiation on ALP, we focus on the impacts of 0.1 THz radiation for 20 min on the activity of ALP in different concentrations. The results reveal that the activity of ALP decreases significantly after exposure to THz radiation. In addition, it could be deduced from fluorescence, ultraviolet-visible(UV-vis), and THz spectra results that THz radiation has induced changes in ALP structures. Our study unlocks non-thermal interactions between THz radiation and ALP, as well as suggests that THz spectroscopy is a promising technique to distinguish ALP structures.

关键词： THz radiation alkaline phosphatase non-thermal effects spectroscopy conformations

AI-boosted software automation:learning from human pair programmers

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Science China(Information Sciences) 2019年第10期62卷 50-52页

作者： xin peng Zhenchang xinG Jun SUN School of Computer Science Fudan University Shanghai Key Laboratory of Data Science Fudan University Research School of Computer Science Australian National University School of Information Systems Singapore Management University

Dear editor,Software automation [1] aims to automatically generate computer programs from formal or informal requirement descriptions. It covers a variety of transformations of different spans, including generating programs from natural-language requirements, requirements specifications, or design specifications. Traditionally software automation is achieved through logical reasoning and rule-based transformation [1]. Although the transformation

关键词： AI-boosted software automation:learning from human pair programmers API pro