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Chiral phosphoramidite ligand-modulated palladium auto-tandem catalysis for asymmetric dehydrogenative dienylation of imines with α-alkenes

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Science China Chemistry 2025年

作者： Zhong-Sheng Nong Hao-fan qian Ying-Chun Chen Pu-Sheng Wang Liu-Zhu Gong Hefei National Research Center for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of China Key Laboratory of Drug Targeting and Drug Delivery System (Sichuan University) Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University School of Materials and Chemistry Southwest University of Science and Technology

The development of efficient processes allowing rapid access to complex chiral molecules from easily available alkenes is a long-term pursuit in the synthetic chemistry community. Transition metal-catalyzed asymmetric functionalization of allylic C–H bond represents a unique alternative toward this goal. However, enantioselective dehydrogenative transformation of olefins to value-added optically enriched molecules remains yet to be discovered. Here, we report a highly enantioselective dehydrogenative dienylation of imines with unactivated α-alkenes driven by the synergistic action of palladium complex and carboxylic acid. Chiral phosphoramidite ligands turned out to be superior in modulating the performance of palladium autotandem catalysis and allowed a broad range of α-alkenes and imines to be transformed into chiral dienylamines. Mechanistic studies suggest that the dienes could be in situ generated from α-alkenes through a palladium(0)-mediated dehydrogenative process in the presence of excess benzoquinone oxidants, and then participated in the Pd-chiral phosphoramidite-catalyzed intermolecular vinylogous-type addition to the imines activated by the carboxylic acid co-catalyst. Notably, the second β-H elimination occurring in the dienylation event might be the turnover-limiting step.

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Poisson Equation on Some Complete Noncompact Manifolds

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Acta Mathematica Sinica,English Series 2007年第4期23卷 623-638页

作者： Xu qian fan Department of Mathematics Ji'nan University Guangzhou 510632 P. R. China

We study the Poisson equation on some complete noncompact manifolds with asymptotically nonnegative curvature. We will also study the limiting behavior of the nonhomogeneous heat equation on some complete noncompact m... 详细信息

关键词： Poisson equation heat equation Green's function

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Influence of Xingnao Jieyu capsule on hippocampal and frontal lobe neuronal growth in a rat model of post-stroke depression

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Neural Regeneration Research 2012年第3期7卷 187-190页

作者： Wentao fan qian Wang Yongmei Yan Shaanxi University of Chinese Medicine Xianyang 712000 Shaanxi Province China

The present study established a rat model of post-stroke depression using incomplete ischemia induced by unilateral carotid artery ligation in combination with solitary raising and subcutaneous injection of a small dose of reserpine. After intragastric perfusion with 45 mg/100 g, 15 mg/100 g, and 7.5 mg/100 g of Xingnao Jieyu for 7, 14 and 21 days, neuronal morphology in the frontal lobe and hippocampus was improved, depression state and voluntary behaviors were also effectively improved in rats with post-stroke depression. Moreover, the effects of Xingnao Jieyu at a dose of 45 and 15 mg/100 g were similar to the traditional antidepressant Prozac.

关键词： Xingnao Jieyu capsule poststroke depression hippocampus neuron traditional Chinese medicine neural regeneration

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Group-based user pairing for virtual MIMO in LTE

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 38-42页

作者： qian Yu fan Bin ZHENG Kan Wireless Signal Processing and Network Laboratory Beijing University ofPosts and Telecommunications Beijing 100876 China

A user pairing method is proposed to improve the throughput gain of virtual multiple input multiple output （virtual MIMO） in 3G long-term evolution（LTE）. The approach taken in this study separated the user pairing into four steps： 1） the users are divided into two groups according to their signal-to-noise ratio （SNR）, and different user pairing metrics are proposed for each group; 2） the scheduler chooses a user for transmitting by a given rule; 3） the scheduler searches the pairing candidate for the selected user in each group; 4） the scheduler chooses the final pairing user from the co-group and crossover-group candidates by using a marginal utility function, to balance fairness and efficiency. The method can improve the throughput of users with high SNR, and guarantee fairness for users with low SNR, so it can be used in 3G LTE systems. The article provides both theoretical analysis and simulation results to support the idea.

关键词： virtual MIMO user pairing 3G LTE space division multiple access (SDMA)

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Hyperactivity of the Lateral Septum Leads to Hypersensitivity in Susceptible Mice

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Neuroscience Bulletin 2023年第9期39卷 1466-1468页

作者： fan qian Xia Zhang Bin Zhang Jie Li Neuropsychiatry Research Institute The Affiliated Hospital of Qingdao UniversityQingdao266000China Department of Neurology West China Hospital of Sichuan UniversityChengdu610041China

Everyone needs social interactions,not only humans but also most *** social interaction feedback is a reward,promoting more social behaviors and acting as a stress *** the contrary,negative social interactions such as school bullying may become a type of stress that leads to mental illnesses including anxiety and depression *** social defeat stress(CSDS)is a widely accepted social trauma model in rodents based on repeated social attacks,following which the defeated mice can be classified as susceptible(SUS)and resilient(RES)according to their social performance.

关键词： stress illness contrary

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Plant-Derived Enzymes Producing Chiral Aroma Compounds and Potential Application

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Phyton-International Journal of Experimental Botany 2023年第2期92卷 383-398页

作者： fang Dong qian fan Xinguo Su Lanting Zeng Guangdong Food and Drug Vocational College Guangzhou510520China National Navel Orange Engineering Research Center College of Life SciencesGannan Normal UniversityGanzhou341000China Tropical Agriculture and Forestry Department Guangdong AIB Polytechnic CollegeGuangzhou510650China Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement&Guangdong Provincial Key Laboratory of Applied Botany South China Botanical GardenChinese Academy of SciencesGuangzhou510650China

Aroma(volatile)compounds play important ecological functions in plants,and also contribute to the quality of plant-derived ***,chiral aroma compounds affect their functions in plants and lead to different flavor quality *** of chiral aroma compounds are due to the presence of enzymes producing these compounds in plants,which are generally involved in the final biosynthetic step of the aroma ***,we review recent progress in research on the plant-derived enzymes producing chiral aroma compounds,and their changes in response to environmental *** chiral aroma enzymes that have been reported produce(R)-linalool,(S)-linalool,(R)-limonene,and(S)-limonene,etc.,and these enzymes are found in various plant *** also discuss the origins of enantioselectivity in the plant-derived enzymes producing chiral aroma compounds and summarize the potential use of plants containing enzymes producing chiral aroma compounds for producing chiral flavors/fragrances.

关键词： Aroma chiral enantioselectivity enzyme plant volatile stereochemistry

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TRPC6:an underlying target for human glaucoma

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International Journal of Ophthalmology(English edition) 2012年第4期5卷 523-526页

作者： qian fan Wen-Bin Huang and Xiu-Lan Zhang Zhongshan Ophthalmic Center State Key Laboratory of Ophthalmology Sun Yat-sen University Guangzhou 510060 Guangdong Province China

Glaucoma is one of the leading causes of visual impairment and blindness worldwide. Of known risk factors for glaucoma, an increased in intraocular pressure is most highly correlated with glaucomatous damage. Irrespective of the cause, apoptosis of the retinal ganglion cells is the eventual outcome. It is widely accepted that glaucoma is a neurodegenerative disease that is strongly correlated with central nervous system disorders, such as Alzheimer's disease. These two disorders also share some similarities in pathogenic mechanisms. Recent studies suggest that the transient receptor potential canonical 6 channel could work together with brain-derived neurotrophic factor to promote neuron survival in brain and retina. In this study, we propose that transient receptor potential canonical 6 may contribute to the pathogenesis of human glaucoma and become a potential therapeutic target.

关键词： glaucoma transient receptor potential canonical 6 channel neuroprotection

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Cod liver oil: a potential protective supplement for human glaucoma

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International Journal of Ophthalmology(English edition) 2011年第6期4卷 648-651页

作者： Wen-Bin Huang qian fan and Xiu-Lan Zhang Zhongshan Ophthalmic Center State Key Laboratory of Ophthalmology Sun Yat-sen University Guangzhou 510060 Guangdong Province China

Glaucoma is one of the leading causes of visual impairment and blindness. Improved knowledge of the pathogenesis of this disease has allowed the exploration of new therapeutic methods. In general, elevated intraocular pressure (IOP), oxidative stress, and vascular insufficiency are accepted as the major risk factors for the progression of glaucoma. Many natural compounds have been found beneficial for glaucoma. Nutritional therapies are now emerging as potentially effective in glaucomatous therapy. One nutritional supplement with potential therapeutic value is cod liver oil, a dietary supplement that contains vitamin A and omega-3 polyunsaturated fatty acids (PUFAs). Vitamin A is important for preserving normal vision and it is a well-known antioxidant that prevents the oxidative damage that contributes to the etiology and progression of glaucoma. Vitamin A is also a crucial factor for maintaining the integrity of conjunctival and corneal ocular surfaces, and preventing the impairment of ocular epithelium caused by topical antiglaucomatous drugs. Omega-3 fatty acids are beneficial for glaucoma patients as they decrease IOP, increase ocular blood flow, and improve optic neuroprotective function. In this article, we propose that cod liver oil, as a combination of vitamin A and omega-3 fatty acids, should be beneficial for the treatment of glaucoma. However, further studies are needed to explore the relationship between cod liver oil and glaucoma.

关键词： cod liver oil glaucoma omega-3 fatty acids vitamin A

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Synthesis and self-assembly of amphiphilic ABA type triblock copolymer with well-defined glycopolymer segments

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Chinese Science Bulletin 2008年第9期53卷 1343-1351页

作者： WANG JianYu qian YanLing ZHANG fan ZHU BaoKu XU YouYi Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education of China Institute of Polymer ScienceZhejiang University Hangzhou 310027 China

A novel amphiphilic ABA type triblock copolymer with well-defined glycopolymer segments was suc- cessfully synthesized via the atom transfer radical polymerization (ATRP) technique, using a bromo-terminated difunctional polysulfone as macroinitiator. The difunctional polysulfone macroini- tiator was prepared by esterifying the phenolic end groups of polysulfone to α-haloesters. This macroinitiator was then used to initiate the polymerization of a glucose-carrying monomer, 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-D-glucofuranose (MAIpG), resulting an ABA type triblock copolymer. After acidolysis treatment, the isopropylidenyl groups of the protected sugar residues were removed, thus the amphiphilic ABA type triblock copolymer with well-defined glycopolymer segments was obtained. The polymers obtained were identified by FT-IR, 1H-NMR, GPC, and TGA. The self-assembly behavior of the amphiphilic glycopolymer in selective solvent (e.g. DMF/H2O) system was also preliminarily explored. The resultant amphiphilic glycopolymer shows potential applications in the fields of controlled release and delivery of drugs, micro-reactors, nano-materials, medical devices, and so on.

关键词：两性分子共聚物丙三醇 ATRP

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Modified reward function on abstract features in inverse reinforcement learning

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第9期11卷 718-723页

作者： Shen-yi CHEN Hui qian Jia fan Zhuo-jun JIN Miao-liang ZHU School of Computer Science and Technology Zhejiang University Hangzhou 310027 China

We improve inverse reinforcement learning(IRL) by applying dimension reduction methods to automatically extract Abstract features from human-demonstrated policies,to deal with the cases where features are either unknown or *** importance rating of each abstract feature is incorporated into the reward *** is performed on a task of driving in a five-lane highway,where the controlled car has the largest fixed speed among all the *** is almost 10.6% better on average with than without importance ratings.

关键词： Importance rating Abstract feature Feature extraction Inverse reinforcement learning(IRL) Markov decision process(MDP)

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