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Isolated elevated aspartate aminotransferase in an asymptomatic woman due to macro-aspartate aminotransferase: A case report

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World Journal of Clinical Cases 2019年第24期7卷 4414-4419页

作者： Meng-ru Zhan Xu Liu Ming-Yuan Zhang Jun-Qi niu Department of Hepatology The First Hospital of Jilin University

BACKGROUND Macro-aspartate aminotransferase(AST), a macroenzyme, is a high-molecular mass complex formed by self-polymerization or association with other serum components that are difficult for the kidney to clear, leading to the isolated elevation of serum AST activity. Cases of macro-AST formation are rare, with only 3 published in the English language literature up to September 2019 in China. In this paper, we present a case in which an asymptomatic woman with persistent isolated elevated AST was confirmed as having macro-AST by the polyethylene glycol precipitation *** SUMMARY A 34-year-old woman was referred to our clinic for elevated AST levels with normal levels of other liver-associated enzymes on November 12, 2018. Her AST level of liver function test had been abnormal for 7 mo before she came to the clinic. The patient was asymptomatic with a normal physical examination. There was no relevant family history and no alcohol consumption or smoking. She had a several-month history of traditional Chinese medical taking and had stopped it 1 year prior. The laboratory tests in our clinic showed only the elevation of AST(89.5 U/L) with no other significant abnormalities. We performed the precipitation technique with polyethylene glycol to confirm the presence of macro-AST. Then for almost a year, her AST level still fluctuated in the abnormal *** This case highlights that clinical physicians should be familiar with this rare condition of persistent isolated AST elevation due to the presence of macro-AST to avoid unnecessary investigation and patient anxiety.

关键词： Aspartate aminotransferase Macroenzymes Macro-aspartate aminotransferase Polyethylene glycol precipitation method China Case report

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Frequency domain decision feedback equalizer for time-reversal space-time block coding

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The Journal of China Universities of Posts and Telecommunications 2012年第1期19卷 38-43页

作者： DONG Chao LIN Jia-ru niu Kai HE Zhi-qiang BIE Zhi-song The Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China

In this paper, a frequency domain decision feedback equalizer is proposed for single carrier transmission with time-reversal space-time block coding （TR-STBC）. It is shown that the diagonal decision feedback equalizer matrix can be calculated from the frequency domain channel response. Under the perfect feedback assumption, the proposed equalizer can approach matched filter bound （MFB）. Compared with the existing time domain decision feedback equalizer, the proposed equalizer exhibits better performance with the same equalization complexity.

关键词： decision feedback equalization matched filter bound time-reversal space-time block coding (TR-STBC)

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Effects of different alloying elements M(M=Fe,Ni,Mn,Si,Mo,Cu,Y)on Cr_(2)0_(3)with Cl:a first-principles study

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Journal of Iron and Steel Research International 2021年第5期28卷 613-620页

作者： ya-nan niu Nan Dong Si Liu Jing yang Pei-de Han Yu-cheng Wu College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Shanxi Engineering Technology Research Center for Energy Materials and Analysis and Testing Taiyuan University of TechnologyTaiyuan 030024ShanxiChina

Using the first-principles methods,the effects of different alloying elements M(M=Fe,Ni,Mn,Si,Mo,Cu,Y)on Cr_(2)0_(3)with Cl adsorption are *** results show that the layer distance of all doped models has been widened to different degrees with Cl *** Mo or Y is doped into the passive film,the difference of layer distance is reduced to a certain *** interaction between alloying elements and Cl is studied by calculating the adsorption height,bond population and electron density *** results show that Mo and Y can inhibit Cl erosion and improve the corrosion resistance of passive ***,we investigate the CrMoFe and CrMoY co-doped system with Cl *** calculations point out that when Mo and Y are doped together in the passive film,the corrosion resistance of the system is more prominent than that of CrMo,CrY and CrMoFe co-doping systems.

关键词： Density functional theory Cr_(2)0_(3) Doping Cl Austenitic stainless steel

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Fluorescence Responses of the Protonation and Deprotonation Processes between Phenolate and Phenol within Rosamine

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Chinese Journal of Chemistry 2018年第1期36卷 42-46页

作者： Ling yang Jinyun niu yanhua Zhan Yujie Xu ru Sun Jianfeng Ge College of Chemistry Chemical Engineering and Material Science Soochow University 199 Ren'Ai Road Suzhou Jiangsu 215123 China School of Radiation Medicine and Protection Medical College of Soochow University Suzhou Jiangsu 215123 China Jiangsu Key Laboratory of Medical Optics Suzhou Institute of Biomedical Engineering and Technology Chinese Academy of Sciences Suzhou215163 China

Two rosamine-based pH probes 1a and 1b with pyronine-phenol skeleton were designed and synthesized by a simple one-step reaction, pH titration experiments showed that probes 1a and 1b exhibit near OFF-ON fluorescence responses around 550--750 nm towards the hydrogen ions. The pKa of the probe 1a is 8.29, while that of the probe lb increases to 12.1 because of the hydrogen bond inside it. Selective and competitive experiments indicated that both common ions and amino acids did not interfere their emission with hydrogen ions. Moreover, confocal fluorescent imaging showed that the probe la could be served as mitochondria biomarker in HeLa and Ges-1 cells.

关键词： rosamine phenolate and phenol protonation and deprotonation pH probe mitochondria biomarker

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Stability Analysis of Hybrid-Driven Underwater Glider

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China Ocean Engineering 2017年第5期31卷 528-538页

作者： niu Wen-dong WANG Shu-xin WANG yan-hui SONG yang ZHU ya-qiang Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education School of Mechanical EngineeringTianjin University The Joint Laboratory of Ocean Observing and Detecting Qingdao National Laboratory for Marine Science and Technology

Hybrid-driven underwater glider is a new type of tmmanned underwater vehicle, which combines the advantages of autonomous underwater vehicles and traditional underwater gliders. The autonomous underwater vehicles have good maneuverability and can travel with a high speed, while the traditional underwater gliders are highlighted by low power consumption, long voyage, long endurance and good stealth characteristics. The hybrid-driven underwater gliders can realize variable motion profiles by their own buoyancy-driven and propeller propulsion systems. Stability of the mechanical system determines the performance of the system. In this paper, the Petrel-II hybrid-driven underwater glider developed by Tianjin University is selected as the research object and the stability of hybrid-driven underwater glider unitedly controlled by buoyancy and propeller has been targeted and evidenced. The dimensionless equations of the hybrid-driven underwater glider are obtained when the propeller is working. Then, the steady speed and steady glide path angle under steady-state motion have also been achieved. The steady-state operating conditions can be calculated when the hybrid-driven underwater glider reaches the desired steady-state motion. And the steady- state operating conditions are relatively conservative at the lower bound of the velocity range compared with the range of the velocity derived from the method of the composite Lyapunov function. By calculating the hydrodynamic coefficients of the Petrel-II hybrid-driven underwater glider, the simulation analysis has been conducted. In addition, the results of the field trials conducted in the South China Sea and the Danjiangkou Reservoir of China have been presented to illustrate the validity of the analysis and *** to show the feasibility of the method of the composite Lyapunov function which verifies the stability of the Petrel-II hybrid-driven underwater glider.

关键词： hybrid-driven underwater glider stability analysis numerical simulation field trials

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Gene Sequence, Soluble Expression and Homologous Comparison of a D-Hydantoinase fromPseudomonas putida YZ-26

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Chemical Research in Chinese Universities 2005年第5期21卷 552-557页

作者： SHI ya-wei ZHAO Li-xia niu Li-xi FENG Xia YUAN Jing-ming Key Laboratory for Chemical Biology and Molecular Engineering of Ministry of Education Institute of Biotechnology Shanxi University Taiyuan 030006 P. R. China

A 1440bp open-reading frame encoding D-hydantoinase from Pseudomonas putida YZ-26 was cloned and sequenced（ GenBank AY387829）. The DNA fragment was inserted into Nde and BamHI sites of vector pET-3a, yielding a recombinant plasmid, pET-HDT. After being transferred into the host strain, the artificial strain, pET-HDT/ E. coli BL21 can express the D-hydantoinase as the soluble form in the Lura-Bertani medium without addition of any inducers. The activity of the enzyme toward substrate DL-hydantoin can reach 3000-4000 IU per cells from one-liter bacterial culture incubated at 30 ℃ for 10-12 h. By the comparison of amino acid sequence homology, hydrophobic residues analysis and secondary structure prediction, it was found that D-hydantoinase reported herein is quite similar to that from Pseudomonas putdia CCRC12857, and alike to that from Pseudomonas putdia DSM84 or other bacteria. A rapid and efficient purification procedure of the enzyme was performed by a three-step procedure： ammonium sulfate fractionation, phenyl Sepharose hydrophobic interaction chromatography and Sephacryl S-200 gel filtration. The molecular mass of the monomeric enzyme is 52042 Da as determined by MALDI-TOF mass spectrometry.

关键词： D-Hydantoinase Gene sequence Soluble expression Homologous comparison Purification Mass spectrum

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Semi-supervised Ladder Networks for Speech Emotion Recognition

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International Journal of Automation and computing 2019年第4期16卷 437-448页

作者： Jian-Hua Tao Jian Huang ya Li Zheng Lian Ming-Yue niu National Laboratory of Pattern Recognition Beijing 100190 China School of Artificial Intelligence University of Chinese Academy of Science (CAS) Beijing 100190 China CAS Center for Excellence in Brain Science and Intelligence Technology Institute of Automation Chinese Academy of Sciences Beijing 100190 China

As a major component of speech signal processing, speech emotion recognition has become increasingly essential to understanding human communication. Benefitting from deep learning, many researchers have proposed various unsupervised models to extract effective emotional features and supervised models to train emotion recognition systems. In this paper, we utilize semi-supervised ladder networks for speech emotion recognition. The model is trained by minimizing the supervised loss and auxiliary unsupervised cost function. The addition of the unsupervised auxiliary task provides powerful discriminative representations of the input features, and is also regarded as the regularization of the emotional supervised task. We also compare the ladder network with other classical autoencoder structures. The experiments were conducted on the interactive emotional dyadic motion capture (IEMOCAP) database, and the results reveal that the proposed methods achieve superior performance with a small number of labelled data and achieves better performance than other methods.

关键词： Speech emotion recognition the ladder network semi-supervised learning autoencoder regularization

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Applications of in-situ solid-state nuclear magnetic resonance in methanol to olefins reaction

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Science China Chemistry 2025年第01期 134-151页

作者： Jing niu Shutao Xu Yingxu Wei Zhongmin Liu National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of Sciences State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The methanol-to-olefins（MTO） reaction offers an alternative pathway for the production of low-carbon olefins from non-oil feedstocks. Fundamental research has been impeded by a lack of comprehensive understanding of its underlying mechanism,despite the significant progress made in industry. In-situ solid-state nuclear magnetic resonance（ss NMR） spectroscopy has emerged as a pivotal tool, offering crucial insights into key species under real-time operando conditions. Furthermore, the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the combination of in-situ13C MAS NMR and 2D correlation spectroscopy. Moreover, recent technological advancements in hyperpolarization（HP） methods, including HP129Xe NMR and dynamic nuclear polarization（DNP）, have significantly improved the sensitivity of ss NMR, enabling detailed structural and kinetic analysis as well as the detection of trace species. In this feature article, we summarized recent advancements in（in-situ） ss NMR spectroscopy applied to MTO reaction processes,encompassing mechanistic investigations at various stages and the intricate host–guest interactions. These theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts, thereby advancing the techniques towards more sustainable and economical production route for olefins.

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Robust Tracking Control of Switched Nonlinear Systems via the Multiple Lyapunov Function Approach

Robust Tracking Control of Switched Nonlinear Systems via th...

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第25届中国控制与决策会议

作者： ya-quan Ma Xin Jin Ben niu yanyan Liu AVIC Shenyang Engine Design and Research Institute College of Mathematics and physics Bohai University School of Information Science and Engineering Northeastern University

ISBN: (纸本)9781467355322

This paper addresses the problem of robust tracking control for a class of switched nonlinear systems via the multiple Lyapunov functions （MLFs） approach. First, a state feedback controller and a state dependent switching law are designed to assure global asymptotic output and state tracking with zero tracking error in the steady state by using linear matrix inequalities （LMIs）. Then, the tracking control method is formulated such that the robust H ∞ tracking performance is achieved. Finally, an example is provided to demonstrate the effectiveness of the main results.

关键词： Switched systems Tracking Multiple Lyapunov functions Linear matrix inequality Uncertainty

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Achievable rate region for the multiple-access channel with multiple cognitive transmitters

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The Journal of China Universities of Posts and Telecommunications 2013年第3期20卷 20-25,24-25页

作者： GUO Yu-chen niu Kai XU Wen-jun HE Zhi-qiang LIN Jia-ru Key Lab of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications

A scenario where one ＇dumb＇ radio and multiple cognitive radios communicating simultaneously with a common receiver is considered. In this paper, we derive an achievable rate region of the multiple-user cognitive multiple-access channel （MUCMAC） under both additive white Gaussian noise （AWGN） channel and rayleigh fading channel, by using a combination of multiple user dirty paper coding （DPC） and superposition coding. Through cognition, it is assumed that the secondary users （SUs） are able to obtain the message of the primary user （PU） non-causally beforehand. Using this side information, the SUs can perform multiple user DPC to avoid the interference from the SU. Besides, the SUs can also allocate part of their transmit power to aid the PU, using superposition coding. Therefore, the capacity region of traditional multiple-access channel （MAC） can be enlarged. Moreover, some asymptotic results are shown as the number of SUs increases. In the AWGN case, it is illustrated that the maximum achievable rate of the PU grows logarithmically with the increase of the number of SUs, whereas in the Rayleigh case, we show that the cognitive gain will increase with the decreasing of the channel signal to noise ratio （SNR）.

关键词： cognitive radios MAC superposition coding DPC

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