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A small,polyphyletic group of Firmicutes synthesizes trimethylamine from L-carnitine

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mLife 2023年第3期2卷 267-271页

作者： Marius Vital Ylenia Heinrich-Sanchez Hannover Medical School Institute for Medical Microbiology and Hospital EpidemiologyHannoverGermany

Impact statement Gut microbiota-derived trimethylamine(TMA)is associated with cardiometabolic disorders and exemplifies a microbial involvement in the etiology of emerging,noncommunicable diseases,the leading causes of death worldwide.Three bio-chemical pathways taking dietary compounds as intake have been described with distinct taxa involved that are all present at low relative abundances.A recently discovered pathway is now considered to be the main route for TMA synthesis from L-carnitine involvingγ-butyrobetaine as an intermediate product.By comprehensive(meta)genomic screening of publicly available data,namely,genomes of the UHGG catalog(n>200,000)and 10 metagenomic(transcriptomic)data sets,we revealed bacteria synthesizing TMA via this pathway and specified their ecophysiology.Results will contribute to stratification of individuals based on their gut microbiota's potential to synthesize TMA and might aid in the development of strategies restricting TMA formation.

关键词： product. synthesize statement

Theoretical study on the vibrational state distribution of product.CO in the photolysis of acetone CH_3COCH_3-→2CH_3 + CO

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Science China Chemistry 1999年第4期42卷 373-381页

作者：李杏利李宗马思渝 Department of Chemistry Beijing Nomal University Beijing China

The photolysis of acetone has been studied at 6-311G basis set using unrestricted Hartree-Fock method. The results show that ground state acetone （S0） cannot easily dissociate. The electrons of acetone undergo n→Ⅱ transition in laser, and excited acetone （T1） can easily dissociate: and acetyl can further undergo thermolytic dissociation: CH3CO→CH3+CO（R2）. The dynamic information (ωK, BKF, V0（S）) of reaction R2 is obtained and the vibrational state distributions of product.CO are calculated. The calculated value consists with the experimental value.

关键词： acetone intrinsic reaction coordinate (IRC) the vibrational state distribution of product.

On Wick product.of generalized operators

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Chinese Science Bulletin 1998年第15期43卷 1252-1256页

作者： Shunlong Luo Jia’an Yan Chinese Acad Sci Inst Appl Math Beijing 100080 Peoples R China

Fundamental properties of Wick product.of generalized operators are investigated. The annihilation and creation algebras are characterized from various points of view. Wick ordering widely used in quantum physics is i... 详细信息

关键词： Gaussian probability space generalized operator S transform Wick product.

A theorem on the transcendency and its applications

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Science China Mathematics 1997年第8期40卷 825-831页

作者：于秀源 Hangzhou Teachers College Hangzhou 310012China

A theorem on the transcendency,for a limit of a sequence of algebraic numbers,is given and used to test the transcendencies of some classes of numbers.

关键词： transcendency algebraic number continued fraction infinite product.

The regular representation and regular covariant representation of crossed product. of Woronowicz C^(*)-algebras

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Science China Mathematics 2005年第9期48卷 1245-1259页

作者： ZHANG Xiaoxia~(1,2) & GUO Maozheng~(1,3) 1. School of Mathematical Sciences,Peking University,Beijing 100871,China 2. Department of Mathematics,Yantai University,Yantai 264005,China 3. LMAM,Peking University,Beijing 100871,China School of Mathematical Sciences Peking University Beijing China Department of Mathematics Yantai University Yantai China LMAM Peking University Beijing China

In this paper, it is shown that the regular representation and regular covariant representation of the crossed product. A×α G correspond to the twisted multiplicative unitary operators, where A is a Woronowicz C*-algebra acted upon by a discrete group G. Meanwhile, it is also shown that the regular covariant C*-algebra is the Woronowicz C*-algebra which corresponds to a multiplicative unitary. Finally, an explicit description of the multiplicative unitary operator for C(SUq(2))×α Z is given in terms of those of the Woronowicz C*-algebra C(SUq(2)) and the discrete group G.

关键词： multiplicative unitary operator, Woronowicz C*-algebra, crossed product.

Semirings which are unions of rings

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Science China Mathematics 2002年第2期45卷 172-195页

作者：郭聿琦 F.Pastijn Dept. of Math. Stat. and Comp. Sci. Marquette University Milwaukee WI 53201-1881 United States Department of Mathematics Yunnan University Kunming 650091 China

Sernirings which are a disjoint union of rings form a variety S which contains the variety of all rings and the variety of all idempotent sernirings, and in particular, the variety of distributive lattices. Various st... 详细信息

关键词： semiring, ring, completely regular semigroup, lattice of varieties, band, idempotent semiring, semilattice, orthodox completely regular semigroup, bisemilattice, orthodox semiring, completely simple semigroup, Mal'cev product.

Effects of non-starch polysaccharide on starch gelatinization and digestibility:a review

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Food Innovation and Advances 2023年第4期2卷 302-312页

作者： Sha Li Wenjing Chen Abel Wend-Soo Zongo Yuanyuan Chen Hongshan Liang Jing Li Bin Li College of Food Science and Technology Huazhong Agricultural UniversityWuhan 430070China Key Laboratory of Environment Correlative Dietology Huazhong Agricultural UniversityMinistry of EducationWuhan 430070China College of Food Science and Technology Zhejiang University of TechnologyHangzhou 310014China

Non-starch polysaccharides have been given wide consideration for their use in starch-based food due to their ability to improve texture,sensory attributes,and functional properties of the end product.In a binary system(starch and non-starch polysaccharides),the characteristics of starch,exemplified as gelatinization and digestibility undergo significant changes.This review article,through a combination of origin and chemical structure-based classification approach,explores the impact of non-starch polysaccharides on starch behavior,concretely for gelatinization and hydrolysis.The underlying mechanism to retard gelatinization gives rise to some colloids that can reduce water accessibility and interact with starch molecules,which vary with the origin.The interfering role of starch hydrolysis attributed to polysaccharides restrict starch swelling,the bulk viscosity,and more ordered structures occur in the mixture.Besides,the role of non-starch polysaccharides on enzymes is another factor.Therefore,this paper gives an overview of how non-starch polysaccharides interfere with starch gelatinization and digestion,which provides a comprehensive understanding of starchy product..

关键词： product. swelling attributed

STRUCTURE AND CHARACTERISTICS OF LEFT CLIFFORD SEMIGROUPS

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Science China Mathematics 1992年第7期35卷 791-805页

作者：朱聘瑜郭聿琦岑嘉评 Department of Mathematics Qinghai Normal University Xining 810008 PRC Department of Mathematics Lanzhou University Lanzhou 730000 PRC Department of Mathematics The Chinese University of Hong Kong

As generalization of Clifford semigroups, left Clifford semigroups are defined and ξ-product. for such semigroups and their semilattice decompositions are studied. In particular, considering how a semilattice decomposition becomes a strong semilattice decomposition and ξ-product.becomes spined product. some structure theorems and characteristics for this class of semigroups are obtained.

关键词： left Clifford semigroup semilattice and strong semilattice of left groups ξ-prduct and spined product.

Structure of the weakly left C-semigroups

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Chinese Science Bulletin 1996年第6期41卷 462-467页

作者：郭聿琦 Department and Institute of Mathematics Yunnan Unrversity Kunming 650091 China

Left (right) C-semigroups are the regular semigroups satisfying the following condition:eSSe (SeeS) for every e∈E (the set of idempotents of S). Refs. [1, 2] give the left(right) semi-spined product.structure and the left (right) △-product.structure of a left(right) C-semigroup, respectively. It is easy to see that the above condition defining a reg-ular semigroup S to be a left (right) C-semigroup may be replaced by the following condi-tion:

关键词： left (weakly left) C-semigroups quasi-C-semigroups left Δ-(right Δ- Δ-) product spined product.