27 results for "Zhang, Li-He"

Explanation by the double-metal-ion mechanism of catalysis for the differential metal ion effects on the cleavage rates of 5′-oxy and 5′-thio substrates by a hammerhead ribozyme

Zhou, De-Min; Zhang, Li-He; Taira, Kazunari

Proc Natl Acad Sci U S A · 1997 · English · PubMed Central

In a previous examination using natural all-RNA substrates that contained either a 5′-oxy or 5′-thio leaving group at the cleavage site, we demonstrated that (i) the attack by the 2′-oxygen at C17 on the phosphorus atom is the rate-limiting step only for the substrate that contains a 5′-thio group…

Methyl Carbonium Ion Migration during the Reaction of 4-Chloro-5-methoxyl-3(2H)-pyridazinone with Trifluoroethylation Agents

Li, Qin; Lin, Guichun; Liu, Li et al.

Molecules · 2009 · English · PubMed Central

To synthesize 4-chloro-5-methoxy-2-(β-trifluoroethyl)-3(2H)-pyridazinone (4), the reactions of 4-chloro-5-methoxy-3(2H)-pyridazinone (5) with RCH(2)CF(3) (R = I, TsO, MsO, TfO) in different solvents were studied. It was found that methyl group migration took place during this reaction. An oxonium…

Studies on the synthesis of a G-rich octaoligoisonucleotide (isoT)(2)(isoG)(4)(isoT)(2) by the phosphotriester approach and its formation of G-quartet structure

Chen, Jun; Zhang, Liang Ren; Min, Ji Mei et al.

Nucleic Acids Res · 2002 · English · PubMed Central

…form a parallel intermolecular G-quadruplex structure. K(+), Na(+) and Li(+) can prompt the formation of G-quartet structures and stabilize them. The effective order of these cations is K(+) > Na(+) > Li(+).

Synthetic N-Alkylated Iminosugars as New Potential Immunosuppressive Agents

Wang, Guan-Nan; Xiong, Yulan; Ye, Jia et al.

ACS Med Chem Lett · 2011 · English · PubMed Central

[Image: see text] The new emerging immunosuppressive effects displayed by iminosugars have not been much investigated so far. Several new N-alkyl dideoxy iminoalditols were designed and synthesized to explore their immunosuppressive effects. These iminosugars inhibited the proliferation of mouse…

A Cell Permeable NPE Caged ADP-Ribose for Studying TRPM2

Yu, Peilin; Wang, Qian; Zhang, Li-He et al.

PLoS One · 2012 · English · PubMed Central

Transient potential receptor melastatin-2 (TRPM2) is a non-selective Ca(2+)-permeable cation channel of the TRPM channel subfamily and is mainly activated by intracellular adenosine diphosphate ribose (ADPR). Here we synthesized a 1-(2-nitrophenyl)ethyl caged ADPR (NPE-ADPR) and found that uncaging…

Dimensions of the optic chiasm: quantitative ultrasound comparison between fetuses with anophthalmia/microphthalmia and normal fetuses

Wu, Li-Hong; Zheng, Qiao; He, Miao et al.

Quant Imaging Med Surg · 2021 · English · PubMed Central

BACKGROUND: The precise pathogenesis of anophthalmia/microphthalmia remains unknown. Prenatal observation of the optic chiasm in fetuses with this malformation would assist in understanding the embryonic development of the condition. The present study aimed to establish the normal fetal size ranges…

Hybrid characteristics of oligonucleotides consisting of isonucleoside 2′,5′-anhydro-3′-deoxy-3′-(thymin-1-yl)-d-mannitol with different linkage modes

Lei, Zhen; Zhang, Ling; Zhang, Liang Ren et al.

Nucleic Acids Res · 2001 · English · PubMed Central

Oligonucleotides consisting of the isonucleoside repeating unit 2′,5′-anhydro-3′-deoxy-3′-(thymin-1-yl)-d-mannitol (4) were synthesized with the monomeric unit 4 incorporated into oligonucleotides as 1′→4′ linkage 4a (oligomer I) or 6′→4′ linkage 4b (oligomer II). The hybrid properties of the two…

Identification of a new Cordyceps javanica fungus isolate and its toxicity evaluation against Asian citrus psyllid

Ou, Da; Zhang, Li‐He; Guo, Chang‐Fei et al.

Microbiologyopen · 2018 · English · PubMed Central

The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most serious pest of citrus worldwide. It acts as a vector for a group of phloem‐limited bacteria (Candidatus Liberibacter spp.) that causes Huanglongbing (HLB) disease. Thus, D. citri management is an important strategy against HLB, and…

Synthesis, physicochemical and biological properties of oligonucleotides incorporated with amino-isonucleosides

Wang, Fang; Chen, Yue; Huang, Ye et al.

Sci China Chem · 2011 · English · PubMed Central

Antisense oligonucleotides (ASONs) and siRNAs have been applied extensively for the regulation of cellular and viral gene expression, and RNAi is currently one of the most promising new approaches for anti-tumor and anti-viral therapy. In order to improve bioactivity properties and physicochemical…

Inhibition of Cardiomyocytes Differentiation of Mouse Embryonic Stem Cells by CD38/cADPR/Ca(2+) Signaling Pathway

Wei, Wen-Jie; Sun, Hai-Ying; Ting, Kai Yiu et al.

J Biol Chem · 2012 · English · PubMed Central

Cyclic adenosine diphosphoribose (cADPR) is an endogenous Ca(2+) mobilizing messenger that is formed by ADP-ribosyl cyclases from nicotinamide adenine dinucleotide (NAD). The main ADP-ribosyl cyclase in mammals is CD38, a multi-functional enzyme and a type II membrane protein. Here we explored the…

Chemoradiotherapy Versus Radiotherapy Alone in Stage II Nasopharyngeal Carcinoma: A Systemic Review and Meta-analysis of 2138 Patients

Xu, Cheng; Zhang, Li-He; Chen, Yu-Pei et al.

J Cancer · 2017 · English · PubMed Central

Background: To explore the value of chemoradiotherapy (CRT) in stage II nasopharyngeal carcinoma (NPC) compared to radiotherapy (RT) alone which includes two-dimensional radiotherapy (2D-RT) and intensity-modulated radiotherapy (IMRT). Methods:All topic-related comparative articles were identified…

Rapid Synthesis of Iminosugar Derivatives for Cell‐Based In Situ Screening: Discovery of “Hit” Compounds with Anticancer Activity

Zhang, Lei; Sun, Fang; Li, Yingxia et al.

ChemMedChem · 2007 · English · PubMed Central

Effective and efficacious drug screening methods are imperative in the drug discovery process. A library has been constructed efficiently and followed by in situ cell‐based screening without product purification. This method led to discovery of several iminosugar derivatives with anticancer…

Comprehensive Assessment of Candidate Reference Genes for Gene Expression Studies Using RT-qPCR in Tamarixia radiata, a Predominant Parasitoid of Diaphorina citri

Guo, Chang-Fei; Pan, Hui-Peng; Zhang, Li-He et al.

Genes (Basel) · 2020 · English · PubMed Central

Tamarixia radiata (Waterston) is a predominant parasitoid of the Asian citrus psyllid (ACP), a destructive citrus pest and vector of huanglongbing (HLB) disease in the fields of southern China. To explore the functioning of target genes in T. radiata, the screening of specific reference genes is…

A Novel Fluorescent Cell Membrane-permeable Caged Cyclic ADP-ribose Analogue

Yu, Pei-Lin; Zhang, Zhe-Hao; Hao, Bai-Xia et al.

J Biol Chem · 2012 · English · PubMed Central

Cyclic adenosine diphosphate ribose is an endogenous Ca(2+) mobilizer involved in diverse cellular processes. A cell membrane-permeable cyclic adenosine diphosphate ribose analogue, cyclic inosine diphosphoribose ether (cIDPRE), can induce Ca(2+) increase in intact human Jurkat T-lymphocytes. Here…

CD38/cADPR/Ca(2+) Pathway Promotes Cell Proliferation and Delays Nerve Growth Factor-induced Differentiation in PC12 Cells

Yue, Jianbo; Wei, Wenjie; Lam, Connie M. C. et al.

J Biol Chem · 2009 · English · PubMed Central

Intracellular Ca(2+) mobilization plays an important role in a wide variety of cellular processes, and multiple second messengers are responsible for mediating intracellular Ca(2+) changes. Here we explored the role of one endogenous Ca(2+)-mobilizing nucleotide, cyclic adenosine diphosphoribose…

Impact of Huanglongbing Pathogen Infection on the Amino Acid Composition in Both Citrus Plants and the Asian Citrus Psyllid

Zhang, Li-He; Ren, Su-Li; Su, Zheng-Qin et al.

Front Physiol · 2021 · English · PubMed Central

The Asian citrus psyllid (ACP) Diaphorina citri is the main vector of the pathogen Candidatus Liberibacter asiaticus (CLas), which is the causal agent of citrus Huanglongbing disease. Feeding by both ACP nymphs and adults on host plants allows them to obtain nutrition. Therefore, the nutritional…

Effects of Endosymbionts on the Nutritional Physiology and Biological Characteristics of Whitefly Bemisia tabaci

Gao, Han; Yin, Xiang-Jie; Fan, Zhen-Huai et al.

Insects · 2025 · English · PubMed Central

Insects and their endosymbionts have a close mutualistic relationship. However, the precise nature of the bacterial endosymbiont-mediated interaction between host plants and whitefly Bemisia tabaci MEAM1 is still unclear. In the present study, six populations of Bemisia tabaci MEAM1 sharing the…

Behavioral and physiological responses of the aphelinid parasitoid, Encarsia formosa, to interspecific competitors

Fan, Ze-Yun; Khan, Muhammad Musa; Lv, Xiao-Lu et al.

Commun Biol · 2025 · English · PubMed Central

The inter- and intra- specific competition is a key factor influencing population dynamics, ecosystem stability, and adaptive evolution in invertebrates, especially within parasitoid communities. Numerous parasitoid species can detect cues left by other parasitoid species, yet it remains unclear…

Tamarixia radiata Behaviour is Influenced by Volatiles from Both Plants and Diaphorina citri Nymphs

Liu, Yan-Mei; Guo, Shu-Hao; Wang, Fei-Feng et al.

Insects · 2019 · English · PubMed Central

Tamarixia radiata (Waterston) is an important ectoparasitoid of the Asian citrus psyllid, Diaphorina citri Kuwayama, a globally destructive pest of citrus. In the present study, a Y-tube olfactometer was employed to investigate whether the parasitoid T. radiata is capable of utilizing the odour…

Correction: Liu et al. Tamarixia radiata Behaviour Is Influenced by Volatiles from Both Plants and Diaphorina citri Nymphs. Insects 2019, 10, 141

Liu, Yan-Mei; Guo, Shu-Hao; Wang, Fei-Feng et al.

Insects · 2024 · English · PubMed Central