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An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

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Science China Chemistry 2024年第9期67卷 2998-3003页

作者： Qi liu Xue-Dong li liang cheng li liu Beijing National Laboratory for Molecular Sciences(BNLMS) CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral ***,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination *** this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent *** addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis *** methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion

Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 2019-2034页

作者： Mingjian li ping Yang Pengyang Zhao Department of Engineering Mechanics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain ***,the physical mechanism underlying this phenomenon remains not fully *** study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal *** derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain ***,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain *** model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic *** simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture.

关键词： Ductile fracture vacancy grain boundary micromechanical finite element method

Improving anammox activity and reactor start-up speed by using CO_(2)/NaHCO_(3) buffer

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Journal of Environmental Sciences 2024年第5期139卷 60-71页

作者： Shaoan cheng Huahua li Xinyuan He Hua Chen Longxin li State Key Laboratory of Clean Energy Utilization College of Energy EngineeringZhejiang UniversityHangzhou 310027China

Anammox bacteria grow slowly and can be affected by large pH *** suitable buffers could make the start-up of anammox reactors easy and *** this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were *** with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox *** with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),*** Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic *** findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.

关键词： Anammox bacteria Buffer solution CO_(2)/NaHCO_(3) Physiological characteristics Microbial community shift

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Petroleum Science 2024年第4期21卷 2383-2392页

作者： li-Ming Zhao Cai-ping Lu Yang liu Chao-Chao li School of Mines China University of Mining and Technology Henan Institute of Geophysical Space Information

The similarities and differences in inherent mechanism and characteristic frequency between the onedimensional(1D) poroelastic model and the layered White model were investigated. This investigation was conducted under the assumption that the rock was homogenous and isotropic at the mesoscopic scale. For the inherent mechanism, both models resulted from quasi-static flow in a slow P-wave diffusion mode, and the differences between them originated from saturated fluids and boundary conditions. On the other hand, for the characteristic frequencies of the models, the characteristic frequency of the 1D poroelastic model was first modified because the elastic constant and formula for calculating it were misused and then compared to that of the layered White model. Both of them moved towards higher frequencies with increasing permeability and decreasing viscosity and diffusion length. The differences between them were due to the diffusion length. The diffusion length for the 1D poroelastic model was determined by the sample length, whereas that for the layered White model was determined by the length of the representative elementary volume(REV). Subsequently, a numerical example was presented to demonstrate the similarities and differences between the models. Finally, published experimental data were interpreted using the 1D poroelastic model combined with the Cole-Cole *** prediction of the combined model was in good agreement with the experimental data, thereby validating the effectiveness of the 1D poroelastic model. Furthermore, the modified characteristic frequency in our study was much closer to the experimental data than the previous prediction, validating the effectiveness of our modification of the characteristic frequency of the 1D poroelastic model. The investigation provided insight into the internal relationship between wave-induced fluid flow(WIFF)models at macroscopic and mesoscopic scales and can aid in a better understanding of the elastic modulus d

关键词： 1D poroelastic model Layered White model Quasi-static flow Slow P-wave diffusion Characteristic frequency Diffusion length

Prediction of cell-cell communication patierns of dorsal root ganglion cells:single-cell RNA sequencing data analysis

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Neural Regeneration Research 2024年第6期19卷 1367-1374页

作者： Yanna lian cheng Wu li liu Xiangyao li National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology Ministry of Education Frontier Science Center for Brain Research and Brain-Machine IntegrationSchool of Brain Science and Brain MedicineZhejiang UniversityHangzhouZhejiang ProvinceChina International Institutes of Medicine the Fourth Affiliated Hospital of Zhejiang University School of MedicineYiwuZhejiang ProvinceChina Zhejiang University-University of Edinburgh Institute Zhejiang University School of MedicineZhejiang UniversityHainingZhejiang ProvinceChina Biomedical Sciences College of Medicine and Veterinary MedicineThe University of EdinburghEdinburghUK Core Facilities of the School of Medicine Zhejiang UniversityHangzhouZhejiang ProvinceChina

Dorsal root ganglion neurons transmit peripheral somatic information to the central nervous system,and dorsal root ganglion neuron excitability affects pain *** root ganglion stimulation is a new approach for managing pain *** of the cell-cell communication among dorsal root ganglion cells may help in the development of new pain and itch management ***,we used the single-cell RNA-sequencing(scRNA-seq)database to investigate intercellular communication networks among dorsal root ganglion *** collected scRNA-seq data from six samples from three studies,yielding data on a total of 17,766 *** on genetic profiles,we identified satellite glial cells,Schwann cells,neurons,vascular endothelial cells,immune cells,fibroblasts,and vascular smooth muscle *** analysis revealed that eight types of dorsal root ganglion neurons mediated proprioceptive,itch,touch,mechanical,heat,and cold ***,we predicted several distinct forms of intercellular communication among dorsal root ganglion cells,including cell-cell contact,secreted signals,extracellular matrix,and neurotransmitter-mediated *** data mining predicted that Mrgpra3-positive neurons robustly express the genes encoding the adenosine Adora2b(A2B)receptor and glial cell line-derived neurotrophic factor family receptor alpha 1(GFRα-1).Our immunohistochemistry results confirmed the coexpression of the A2B receptor and GFRα-*** injection of the A2B receptor antagonist PSB-603 effectively prevented histamine-induced scratching behaviour in a dose-dependent *** results demonstrate the involvement of the A2B receptor in the modulation of itch ***,our findings provide insight into dorsal root ganglion cell-cell communication patterns and *** results should contribute to the development of new strategies for the regulation of dorsal root ganglion excitability.

关键词： cell-cell communications CellChat dorsal root ganglion scRNA-Seq database

The innovative safe herbicide dienediamine saves paraquat

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Molecular Plant 2024年第1期17卷 11-12页

作者： Jin-Qiu Xia ping Xu cheng-Bin Xiang Division of life Sciences and Medicine Division of Molecular&Cell BiophysicsHefei National Science Center for Physical Sciences at the MicroscaleMOE Key Laboratory for Membraneless Organelles and Cellular DynamicsUniversity of Science and Technology of ChinaThe Innovation Academy of Seed DesignChinese Academy of SciencesHefeiAnhui Province 230027China Shanghai Key Laboratory of Plant Functional Genomics and Resources Shanghai Chenshan Botanical GardenShanghai Chenshan Plant Science Research CenterCAS Center for Excellence in Molecular Plant SciencesShanghai 201602China

Throughout the history of agriculture,the challenge of weed management has endured,necessitating significant investments to facilitate ideal crop growth and maximize *** for weed control mainly involve manual and chem... 详细信息

关键词： approach. manual chemical

Microdeletion on Xq27.1 in a Chinese VACTERL-like Family with Kidney and Anal Anomalies

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Biomedical and Environmental Sciences 2024年第5期37卷 503-510页

作者： li Min ZHANG Yu Lan ZHANG Kai li li ping ping LYU Yu Han liANG Ya Xin YU Yue Department of Gynecology and Obstetrics Beijing HospitalNational Center of GerontologyInstitute of Geriatric MedicineChinese Academy of Medical SciencesBeijing 100730China Chinese Academy of Medical Sciences and Peking Union Medical College Beijing HospitalBeijing 100730China The Key Laboratory of Geriatrics Beijing Institute of GeriatricsBeijing HospitalNational Center of GerontologyInstitute of Geriatric MedicineChinese Academy of Medical SciencesBeijing 100730China

Objective VATER/VACTERL-like association is associated with adverse pregnancy *** evidence of this disorder is *** this study,we aimed to provide genetic insights to improve the diagnosis of *** We have described a Chinese family in which four members were affected by renal defects or agenesis,anal atresia,and anovaginal fistula,which is consistent with the diagnosis of a VACTERL-like *** and genetic analyses were conducted using genome and exome *** Segregation analysis revealed the presence of a recessive X-linked microdeletion in two living affected individuals,harboring a 196–380 kb microdeletion on Xq27.1,which was identified by familial exome *** sequencing was performed on the affected male,confirming a-196 kb microdeletion in Xq27.1,which included a 28%loss of the CDR-1 *** family members were included in the co-segregation analysis,and only VACTERL-like cases with microdeletions were reported in *** These results suggest that the 196–380 kb microdeletion in Xq27.1 could be a possible cause of the VATER/VACTERL-like ***,further genetic and functional analyses are required to confirm or rule out genetic background as the definitive cause of the VACTERL association.

关键词： Prenatal diagnosis VACTERL whole-genome sequencing whole-exome sequencing X-linked

Rapid prediction of damaged ship roll motion responses in beam waves based on stacking algorithm

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Journal of Hydrodynamics 2024年第2期36卷 394-405页

作者： Xin-ran liu Ting-qiu li Zi-ping Wang School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan430063China

Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI *** paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD *** general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting *** offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for *** is clearly demonstrated that the predicted response amplitude operator(RAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics *** high-quality CFD samples,therefore,implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of determination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various ***,the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.

关键词： Ship motion damaged ship computational fluid dynamics(CFD) machine learning stacking algorithm

血液净化膜材在凝血过程中对凝血十二因子的接触活化

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四川大学学报（工程科学版） 2005年第3期37卷 86-89页

作者：程莉萍乐以伦四川大学材料科学与工程学院四川成都610065 四川大学高分子科学与工程学院四川成都610065

对6种血液净化膜材:不同磺化度的磺化聚醚砜(PES-SO3Na-Ⅰ、PES-SO3Na-Ⅱ)、聚醚砜(PES)、聚砜(PS)、聚甲基丙烯酸甲酯(PMMA)、醋酸纤维素(CA)在体外静态接触血浆时对凝血十二因子(FXII)的接触活化程度进行了研究,并据此评价这些材料的... 详细信息

对6种血液净化膜材:不同磺化度的磺化聚醚砜(PES-SO3Na-Ⅰ、PES-SO3Na-Ⅱ)、聚醚砜(PES)、聚砜(PS)、聚甲基丙烯酸甲酯(PMMA)、醋酸纤维素(CA)在体外静态接触血浆时对凝血十二因子(FXII)的接触活化程度进行了研究,并据此评价这些材料的血液相容性。先将膜材与血浆在37℃孵育一定时间,然后测定材料结合FXII的活化产物α-FXIIa的促凝活性和被孵育血浆中未活化FXII的促凝活性。这些材料活化FXII的程度由大到小的次序是PMMA>CA>PS>PES>PES-SO3Na-I>PES-SO3Na-II。PES有着良好的血液相容性,并且通过磺化可进一步提高其血液相容性。

关键词：接触活化凝血十二因子血液净化生物材料