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Synthetic control of chiral pore surfaces in covalent organic frameworks for enantioselective separation of chiral drugs

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Science China Chemistry 2025年

作者： Shiguo Fu Xiaofeng Zhang Kaixuan Wang Linfeng Chen fan Xia Yong Cui yan Liu School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Faculty of Materials Science and Chemistry China University of Geosciences

Enantioselective separations of racemates using porous materials are highly attractive and significant in both fundamental research and technological applications. However, achieving controlled chiral pore surfaces to create the necessary driving force for enantiomer discrimination poses a fundamental challenge. Herein, we demonstrate that chiral covalent organic frameworks(COFs) possess the essential characteristics for effective enantioseparations through synthetic control over pore surfaces. We synthesized three 3D chiral COFs (CCOFs) featuring abundant chiral recognition sites on the pore walls via the condensation of enantiopure dialdehyde of 2,2′-dihydroxy-1,1′-binaphthyl and tetraamine. All CCOFs with high stability exhibit an 11-fold interpenetrated framework with tubular open channels, decorated with dihydroxyl or diethoxyl groups. The CCOFs with dihydroxyl groups serve as solid adsorbents for the adsorptive separation and solid-phase extraction of various chiral 1-phenylethanol-derived enantiomers, particularly racemic drugs, achieving up to 98%enantiomeric excess. In contrast, the CCOF with diethoxy groups is unable to resolve the racemates. These CCOF materials can be recycled and reused without any apparent loss of performance. Density functional theory (DFT) calculations reveal that the enantiospecific recognition arises from the well-organized chiral inner sphere and multiple chiral host-guest interactions.

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Can patients with mild non-neoplastic lesions diagnosed at baseline screening be safely exempt from surveillance: evidence from multicenter community-based cohorts

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Science China Life Sciences 2025年第1期68卷 263-271页

作者： Siyi He Zhiyi Zhang Guohui Song Zhenhai Wang Chunyun Dai Shipeng yan Kun Jiang Bingbing Song He Li Maomao Cao Dianqin Sun fan.yan. Xinxin yan Shaoli Zhang Yi Teng Qianru Li Changfa Xia Wanqing Chen Office of Cancer Screening National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical College Department of Gastroenterology Gansu Wuwei Tumor Hospital Cixian Cancer Institute Linzhou Cancer Hospital Center for Disease Control and Prevention of Sheyang County Department of Cancer Prevention and Control Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of MedicineCentral South University Luoshan Center for Disease Control and Prevention Office for Cancer Control and Research Affiliated Cancer Hospital of Harbin Medical University

Surveillance recommendations for gastric cancer（GC） in current guidelines focused on advanced precancerous lesions and were based on precise diagnosis of severity/extent of baseline lesions. We aimed to develop a less endoscopy-related equipment-dependent risk-stratification tool, and assessed whether mild-precursor-lesion patients can be safely exempt from surveillance. In the multicenter communitybased cohort, 75,051 participants receiving baseline endoscopy were enrolled during 2015–2017 and followed-up until 2021. Cumulative incidence rates（CIRs） of GC for precancerous-conditions were calculated by Kaplan-Meier method and compared by Log-rank tests. Mixedeffects Cox regression models were used to detect potential factors for progression towards GC. A risk score was calculated as counts of selected factors. An independent cohort, including 26,586 participants was used for external validation. During a median follow-up of 6.25 years, CIRs of GC were 0.302%, 0.436%, and 4.756% for normal group, non-neoplastic（atrophic gastritis/intestinal metaplasia） and neoplastic lesions（low-grade/high-grade dysplasia）, respectively(Ptrend<0.001). Four predictors, including male, ≥60 years, smoking, and limited vegetable consumption, were selected for risk-stratification. High-risk patients（≥3 risk factors） with non-neoplastic lesions showed higher GC risks（adjusted HR=7.73, 95%CI: 4.29–13.92）, and their four-year CIR reached the one-year CIR of neoplastic lesions. Further categorizing non-neoplastic lesions by histological grade, both patients with moderate-to-severe lesions（aHR=3.07, 95%CI: 1.67–5.64） and high-risk patients with mild lesions（aHR=7.29, 95%CI: 3.58–14.86） showed higher risks. Consistent trends were observed in validation cohort. High-risk mild-precursor-lesion patients should receive surveillance within 3–5 years after baseline screening. Our study provides evidence on supplementing current guideline recommendations.

关键词： stomach neoplasms precancerous conditions cancer screening cumulative incidence risk stratification

Maintaining moderate levels of hypochlorous acid promotes neural stem cell proliferation and differentiation in the recovery phase of stroke

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Neural Regeneration Research 2025年第3期20卷 845-857页

作者： Lin-yan Huang Yi-De Zhang Jie Chen Hai-Di fan Wan Wang Bin Wang Ju-Yun Ma Peng-Peng Li Hai-Wei Pu Xin-Yian Guo Jian-Gang Shen Su-Hua Qi School of Medical Technology Xuzhou Key Laboratory of Laboratory DiagnosticsXuzhou Medical UniversityXuzhouJiangsu ProvinceChina School of Pharmacy Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina Department of Laboratory Medicine Branch Hospital of Huai’an First People’s HospitalHuai’anJiangsu ProvinceChina Department of Laboratory Medicine the Affiliated Hospital of Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina School of Chinese Medicine The University of Hong KongHong Kong Special Administrative RegionChina

It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late ***,previous studies have shown that excessive increases in hypochlorous acid after stroke can cause severe damage to brain *** previous studies have found that a small amount of hypochlorous acid still exists in the later stage of stroke,but its specific role and mechanism are currently *** simulate stroke in vivo,a middle cerebral artery occlusion rat model was established,with an oxygen-glucose deprivation/reoxygenation model established in vitro to mimic *** found that in the early stage(within 24 hours)of ischemic stroke,neutrophils produced a large amount of hypochlorous acid,while in the recovery phase(10 days after stroke),microglia were activated and produced a small amount of hypochlorous ***,in acute stroke in rats,hypochlorous acid production was prevented using a hypochlorous acid scavenger,taurine,or myeloperoxidase inhibitor,4-aminobenzoic acid *** results showed that high levels of hypochlorous acid(200μM)induced neuronal apoptosis after oxygen/glucose deprivation/***,in the recovery phase of the middle cerebral artery occlusion model,a moderate level of hypochlorous acid promoted the proliferation and differentiation of neural stem cells into neurons and *** suggests that hypochlorous acid plays different roles at different phases of cerebral ischemia/reperfusion *** levels of hypochlorous acid(5 and 100μM)promoted nuclear translocation ofβ-*** transfection of single-site mutation plasmids,we found that hypochlorous acid induced chlorination of theβ-catenin tyrosine 30 residue,which promoted nuclear ***,our study indicates that maintaining low levels of hypochlorous acid plays a key role in the recovery of neurological function.

关键词： cell differentiation cerebral ischemia/reperfusion injury chlorination hypochlorous acid microglia neural stem cell neurogenesis nuclear translocation stroke β-catenin

Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

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Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu yan-Bo Li Qi Zhang Jun-Zhao Xiao Yi-fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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Enhancement and Application of Overset Grid Assembly

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Chinese Journal of Aeronautics 2010年第6期23卷 631-638页

作者： fan Jingjing yan Chao National Laboratory of Computational Fluid Dynamics Beijing University of Aeronautics and AstronauticsBeijing 100191China

In this article, the overset grid assembly method is improved to efficiently solve several critical problems that occur when applying overset grids to the complicated geometries and moving body. First, instead of using the two-step searching (i.e. cut and paste), a single-step searching method based on the grid cell size is proposed to modify holes and optimize the grid overlapping automatically. Second, discrepancies between the wall surface representations, where the grids overlap, are handled by introducing the wall's normal directions to the hole-map and projecting the interpolated points on the recipient mesh into the donor mesh. Finally, the dynamic overset method is modified to address the complex moving body problem. At every time step, the initial hole surface of the previous time step is dynamically adjusted to accomplish hole cutting and avoid the time consuming hole-map procedure. Numerical experiments show that the enhanced overset grid assembly method obtains satisfactory results.

关键词： overset grid hole-map hole-surface optimization surface grid overset dynamic overset

Robust adaptive control of hypersonic vehicle considering inlet unstart

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Journal of Systems Engineering and Electronics 2022年第1期33卷 188-196页

作者： WANG fan fan Pengfei fan Yonghua XU Bin yan Jie College of Astronautics Northwestern Polytechnical UniversityXi’an 710072China College of Automation Northwestern Polytechnical UniversityXi’an 710072China

In this paper,a model reference adaptive control(MRAC)augmentation method of a linear controller is proposed for air-breathing hypersonic vehicle(AHV)during inlet *** the development of hypersonic flight technology,hypersonic vehicles have been gradually moving to the stage of *** the maneuvers,changes of attitude,Mach number and the back pressure can cause the inlet unstart phenomenon of *** unstart causes significant changes in the aerodynamics of AHV,which may lead to deterioration of the tracking performance or instability of the control ***,we firstly establish the model of hypersonic vehicle considering inlet unstart,in which the changes of aerodynamics caused by inlet unstart is described as nonlinear ***,an MRAC augmentation method of a linear controller is proposed and the radial basis function(RBF)neural network is used to schedule the adaptive parameters of ***,the Lyapunov function is constructed to prove the stability of the proposed ***,numerical simulations show that compared with the linear control method,the proposed method can stabilize the attitude of the hypersonic vehicle more quickly after the inlet unstart,which provides favorable conditions for inlet restart,thus verifying the effectiveness of the augmentation method proposed in the paper.

关键词： air-breathing hypersonic vehicle(AHV) inlet unstart model reference adaptive control augmentation(MRAC) radial basis function(RBF)neural network

Effect of swirling flow on platelet concentration distribution in small-caliber artificial grafts and end-to-end anastomoses

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Acta Mechanica Sinica 2011年第5期27卷 833-839页

作者： fan Zhan Yu-Bo fan Xiao-yan Deng Key Laboratory for Biomechanics and Mechanobiologyof Ministry of Education School of Biological Science and Medical EngineeringBeihang University 100191 Beijing China

Platelet concentration near the blood vessel wall is one of the major factors in the adhesion of platelets to the *** our previous studies,it was found that swirling flows could suppress platelet adhesion in small-caliber artificial grafts and end-to-end *** order to better understand the beneficial effect of the swirling flow,we numerically analyzed the near-wall concentration distribution of platelets in a straight tube and a sudden tubular expansion tube under both swirling flow and normal flow *** numerical models were created based on our previous experimental *** simulation results revealed that when compared with the normal flow,the swirling flow could significantly reduce the near-wall concentration of platelets in both the straight tube and the expansion *** present numerical study therefore indicates that the reduction in platelet adhesion under swirling flow conditions in small-caliber arterial grafts,or in end-to-end anastomoses as observed in our previous experimental study,was possibly through a mechanism of platelet transport,in which the swirling flow reduced the near-wall concentration of platelets.

关键词： Platelet near-wall concentration · Swirling flow · Small-caliber arterial grafts · End-to-end anastomosis

Risk factors for developing osteoporosis in diabetic kidney disease and its correlation with calcium-phosphorus metabolism,FGF23,and Klotho

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World Journal of Diabetes 2025年第1期16卷 49-57页

作者： fan.yan. yan Wu Wei Zhang Department of Endocrinology Wuhu Second People's HospitalWuhu 241000Anhui ProvinceChina Department of Nephrology Wuhu Second People's HospitalWuhu 241000Anhui ProvinceChina

BACKGROUND The progression of diabetic kidney disease(DKD)affects the patient’s kidney glomeruli and tubules,whose normal functioning is essential for maintaining normal calcium(Ca)and phosphorus(P)metabolism in the *** risk of developing osteoporosis(OP)in patients with DKD increases with the aggravation of the disease,including a higher risk of fractures,which not only affects the quality of life of patients but also increases the risk of *** To analyze the risk factors for the development of OP in patients with DKD and their correlation with Ca-P metabolic indices,fibroblast growth factor 23(FGF23),and *** One hundred and fifty-eight patients with DKD who were admitted into the Wuhu Second People’s Hospital from September 2019 to May 2021 were selected and divided into an OP group(n=103)and a normal bone mass group(n=55)according to their X-ray bone densitometry *** data and differences in Ca-P biochemical indices,FGF23,and Klotho were *** correlation of Ca-P metabolic indices with FGF23 and Klotho was discussed,and the related factors affecting OP in patients with DKD were examined by multivariate logistic regression *** The OP group had a higher proportion of females,an older age,and a longer diabetes mellitus duration than the normal group(all P<0.05).Patients in the OP group exhibited significantly higher levels of intact parathyroid hormone(iPTH),blood P,Ca-P product(Ca×P),fractional excretion of phosphate(FeP),and FGF23,as well as lower estimated glomerular filtration rate,blood Ca,24-hour urinary phosphate excretion(24-hour UPE),and Klotho levels(all P<0.05).In the OP group,25-(OH)-D3,blood Ca,and 24-hour UPE were negatively correlated with FGF23 and positively correlated with *** contrast,iPTH,blood Ca,Ca×P,and FeP exhibited a positive correlation with FGF23 and an inverse association with Klotho(all P<0.05).Moreover,25-(OH)-D3,iPTH,blood Ca,FePO4,FGF23,Klotho,age,and female gender were key fa

关键词： Diabetic kidney disease Osteoporosis Calcium-phosphorus metabolism FGF23 Klotho

Multi-objective quality control method for cold-rolled products oriented to customized requirements

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International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1332-1342页

作者： Yi-fan.yan.Zhi-min Lü Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China

To deal with the increasing demand for low-volume customization of the mechanical properties of cold-rolled products, a two-way control method based on mechanical property prediction and process parameter optimization(PPO) has become an effective solution. Aiming at the multi-objective quality control problem of a company's cold-rolled products, based on industrial production data, we proposed a process parameter design and optimization method that combined multi-objective quality prediction and PPO. This method used the multi-output support vector regression(MSVR) method to simultaneously predict multiple quality indices. The MSVR prediction model was used as the effect verification model of the PPO results. It performed multi-process parameter collaborative design and realized the optimization of production process parameters for customized multi-objective quality requirements. The experimental results showed that, compared with the traditional single-objective quality prediction model based on support vector regression(SVR), the multi-objective prediction model could better take into account the coupling effect between process parameters and quality index, the MSVR model prediction accuracy was higher than that of the SVR, and the optimized process parameters were more capable and reflected the influence of metallurgical mechanism on the quality index,which were more in line with actual production process requirements.

关键词： customized production quality control multi-objective prediction multi-output support vector regression process parameter optimization