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Synthesis of A Novel Fulleroaziridine Carrying 4-Deoxy-4'-demethylepipodophyllotoxin

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Chinese Chemical Letters 2003年第11期14卷 1123-1126页

作者： qian rong LI Sha YANG Structure Research Laboratory University of Science and Technology of ChinaHefei 230026

A novel fulleroaziridine 2 with a closed 6,6-ring junction was synthesized from [60]fullerene and 4-azido-4-deoxy- 4?demethylepipodophyllotoxin 1 in 1, 2-dichlorobenzene at 110℃ for 45 h, in a yield of 39.3 % based o... 详细信息

关键词： Podophyllotoxin derivative azide fullerene fulleroaziridine cycloaddition.

Characterization of 4-Aryl-5-ethoxycarbonyl-6-methyl-3,4-dihydro-pyrimidin-2(1H)-thiones by EI-TOF Mass Spectrometry

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Chemical Research in Chinese Universities 2006年第1期22卷 40-44页

作者： LI qian-rong XUE Song YIN Hao Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry University of Science and Technology of China Hefei 230026 P. R. China

The electron impact （EI） time-of-flight mass spectra （TOFMS） of the title compounds （ thioxo-Biginelli compounds） were studied to establish their fragmentation pathways. With a TOF instrument of high resolution, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the ionic elemental compositions for all the compounds through interpretation by software. By further applying chemical intuition, majority of the fragmentation ions were fully assigned. All the compounds give strong signals（ average 76% ） for their molecular ions in the El spectra. Two kinds of characteristic fragmentation pathways from the molecular ion were observed. One is related to the loss of the ester group, forming a resonance stabilized ion with a moderate abundance（ average 40% ）. The other concerns the loss of the aromatic-ring radical, forming another resonance stabilized ion at m/z 199 with a high abundance（ average 79% ）, from which further important fragmentations including the formation of an ion at m/z 171 （average 24% ） by the loss of C2H2 （via the McLafferty rearrangement）, and an ion at m/z 153（ average 10% ） by the elimination of a water molecule preceed. In addition, ion [ M - Et ]^＋ with a high abundance（average 62% ） is a characteristic for the Biginelli compounds with an ethoxycarbonyl group. Differences and similarities among the fragmentations observed from the EI-TOFMS of oxo-Biginelli compounds are discussed.

关键词： Beginelli compound 3,4-Dihydropyrimidinthione Time-of-flight mass spectrometry Electron impact

Toward favorable detection performance and low complexity by incorporating MIMO detection with ARQ

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The Journal of China Universities of Posts and Telecommunications 2011年第3期18卷 69-74页

作者： QI Yuan qian rong-rong PENG Tao WANG Wen-bo School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China Key Laboratory of Universal Wkeless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China Automation School Beijing University of Posts and Telecommunications Beijing 100876 China

Although multiple-input-multiple-output （MIMO） detection has received much research attention in the past years, to the author＇s knowledge, few detection methods demonstrate optimal/near-optimal performance with low complexity. This paper proposes to incorporate automatic retransmission request （ARQ） with sub-optimal MIMO detectors so as to achieve both favorable performance and low complexity. In the study, retransmission delay induced by ARQ is exploited as a source of improving the detection performance of low complexity algorithms. In particular, the detection performance of sub-optimal algorithms improved by introducing ARQ is analyzed theoretically. A sufficient condition for such scheme to achieve full-diversity performance is also derived which relates detection performance with number of transmission times. Moreover, throughput cost by retransmission is deduced as well as its lower bound. The zero-forcing （ZF） equalizer cooperating with ARQ, as a case study, is shown to have evident performance improvement through theoretical analysis. And numerical results are presented to verify the effectiveness of the proposed scheme which boosts the performance of sub-optimal detector and possesses lower implementation complexity for practical reality simultaneously.

关键词： MIMO ARQ complexity performance

Complexity study of sphere decoding in multi-antenna systems

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The Journal of China Universities of Posts and Telecommunications 2010年第3期17卷 1-5页

作者： qian rong-rong QI Yuan PENG Zao WANG Wen-bo Wireless Signal Processing and Network Lab (Key Lab of Universal Wireless Communication Ministry of Education) Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this article a bridge between the expected complexity and performance of sphere decoding （SD） is built. The expected complexity of SD for infinite lattices is then investigated, which naturally is the upper-bound of those for all the finite lattices if given by the same channel matrix and signal noise ratio （SNR）. Such expected complexity is an important characterization of SD in multi-antenna systems, because no matter what modulation scheme is used in practice （generally it has finite constellation size） this upper-bound holds. Above bridge also leads to a new method of determining the radius for SD. The numerical results show both the real value and upper-bound of average searched number of candidates in SD for 16-QAM modulated system using the proposed sphere radius determining method. Most important of all new understandings of expected complexity of SD are given based on above mentioned theoretic analysis and numerical results.

关键词： MIMO sphere decoding expected complexity

Studies on the Element Characteristics of Nephrite Minerals from Different Deposits by GD-MS

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Chinese Journal of Chemistry 2011年第6期29卷 1251-1255页

作者： Siqinbilige qian, rong Zhuo, Shangjun Gan, Fuxi Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China Shanghai Mass Spectrometry Center Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China Fudan University Shanghai 200433 China

Element characteristics of nephrite minerals were determined by glow discharge mass spectrometry （GD-MS） through surface adherence method. To solve the conductivity problem of non-conductive nephrite samples, high purity indium pin （〉99.9999%） was used as discharge host. During the preparation procedure, a small piece of nephrite sample was ground into powder （about 200 meshes）, and then the sample powder was coated on the surface of indium pin to form a rod sample. Typical elements of nephrite minerals were analyzed by GD-MS, and the relative standard deviations showed that the stability and reproducibility of this method were good. Meanwhile, four nephrite samples from two different deposits were further studied by this method. The GD-MS results of major elements and trace elements revealed that typical elements of the nephrite minerals from same deposit were similar, and those from different deposits exhibited significant difference. In addition, results of external-beam proton induced X-ray emission （PIXE） were consistent with the result of GD-MS determination. The present approach had been proven to be simple, efficient to perform the rapid screening and multi-element semi-quantitative analysis of nephrite samples.

关键词： glow discharge mass spectrometry nephrite element characteristics trace analysis

Regioselective Propargylation of Aldehydes with Propargyl Bromide Mediated by Sn-In in Aqueous Media under Microwave Irradiation

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Chinese Chemical Letters 2005年第12期16卷 1573-1576页

作者： Cheng Zhi GU qian rong LI Hao YIN Structure Research Laboratory University of Science and Technology of China Hefei 230026

Tin-indium were employed in the propargylations of various aldehydes with propargyl bromide in the presence of SnCl2 and C6H5（CH3）3NBr under microwave irradiation to afford the corresponding homopropargyl alcohols exclusively in high yields. All the reactions were completed smoothly in predominantly aqueous media in 200 seconds only.

关键词： Propargylation aldehydes tin-indium regioselectivity microwave

Toll-like receptor signaling in colorectal cancer:carcinogenesis to cancer therapy

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World Journal of Gastroenterology 2014年第47期20卷 17699-17708页

作者： Ting-Ting Li Shuji Ogino Zhi rong qian Department of Geriatric Gastroenterology Chinese PLA General Hospital Department of Medical Oncology Dana-Farber Cancer Institute and Harvard Medical SchoolBostonMA 02215United States Department of Pathology Brigham and Women’s Hospital and Harvard Medical SchoolBostonMA 02215United States Department of Epidemiology Harvard School of Public HealthBostonMA 02215United States

Toll-like receptors (TLRs) are germ line encoded innate immune sensors that recognize conserved microbial structures and host alarmins, and signal expression of major histocompatibility complex proteins, costimulatory molecules, and inflammatory mediators by macrophages, neutrophils, dendritic cells, and other cell types. These protein receptors are characterized by their ability to respond to invading pathogens promptly by recognizing particular TLR ligands, including flagellin and lipopolysaccharide of bacteria, nucleic acids derived from viruses, and zymosan of fungi. There are 2 major TLR pathways; one is mediated by myeloid differentiation factor 88 (MYD88) adaptor proteins, and the other is independent of MYD88. The MYD88-dependent pathway involves early-phase activation of nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NF-κB1) and all the TLRs, except TLR3, have been shown to activate this pathway. TLR3 and TLR4 act via MYD88-independent pathways with delayed activation of NF-κB signaling. TLRs play a vital role in activating immune responses. TLRs have been shown to mediate inflammatory responses and maintain epithelial barrier homeostasis, and are highly likely to be involved in the activation of a number of pathways following cancer therapy. Colorectal cancer (CRC) is one of the most common cancers, and accounts for almost half a million deaths annually worldwide. Inflammation is considered a risk factor for many common malignancies including cancers of the colorectum. The key molecules involved in inflammation-driven carcinogenesis include TLRs. As sensors of cell death and tissue remodeling, TLRs may have a universal role in cancer; stimulation of TLRs to activate the innate immune system has been a legitimate therapeutic strategy for some years. TLRs 3/4/7/8/9 are all validated targets for cancer therapy, and a number of companies are developing agonists and vaccine adjuvants. On the other hand, antagonists may fav

关键词： Toll-like receptor Colorectal cancer Carcinogenesis Prognosis Cancer therapy

Synthesis and Characterization of a Novel Podophyllotoxin Derivative Containing a Cyclohexadienone Group

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Chemical Research in Chinese Universities 2007年第4期23卷 421-425页

作者： LI qian-rong PAN Zhen YIN Hao WANG Wei Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei 230026 P. R. China

4β-Azido-4-demethyl-4＇-O-demethyl-epipedophyllotoxin reacted with phenyliodonium diacetate in MeOH at room temperature to synthesize a novel pedophyllotoxin derivative containing a cyclohexadienone group with the original configurations of C2 and C4, which are required for the antitumor activities. The component and structure of the pro-duct were confirmed using elemental analysis, high-resolution mass spectrum, ^1H and ^13C NMR spectra, and infrared spectrum. Furthermore, the fragmentation routes of the product were fully assigned with electron-impaet time-of-flight mass spectrometry（ EI-TOF MS）, which can also be used for the structural elucidation based on the molecular ion at m/z 455（16% ） and three novel characteristic fragment ions at m/z 183（37% ）, 425（7% ）, and 199（5% ）. The cyclohexadienone product is sensitive to acidic media. When it is treated with a trace of acid, another novel derivative containing an orthoquinone moiety is formed, which links with the metabolism of the cancer inhihitors.

关键词： Podophyllotoxin derivative PIDA Structural elucidation

Reactions of Podophyllotoxin with DDQ

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Chinese Chemical Letters 2001年第12期12卷 1057-1060页

作者： qian rong LI Ting Hu ZHANG Robert S.WARD Structure Research Laboratory University of Science and Technology of ChinaHefei 230026 Chemistry Department University of Wales SwanseaSingleton ParkSwansea SA2 8PP UK

Podophyllotoxin I reacts with DDQ in acetic acid to give podophyllotoxone 2 at 75 degreesC and the naphthol 3 at 90 degreesC, and in TFA to give the naphthalene 4. 4'-O-Benzyl-epipodophyllotoxin 5 reacts with DDQ in a... 详细信息

关键词： podophyllotoxin oxidation DDQ