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Characterization of dual enzyme resulted from bicistronic expression of two β-glucanases in porcine cells

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Journal of Integrative Agriculture 2015年第4期14卷 732-740页

作者： ZHANG Xian-wei li zi-cong MENG Fan-ming WANG De-hua liU De-wu HE Xiao-yan SUN Yue BAI Yin-shan WU Zhen-fang National Engineering Research Center for Breeding Swine Industry South China Agricultural University Wen's Research Institute Guangdong Wen's Food Group Co.Ltd.

Many animal feed grains contain high β-glucan in the cell wall. Pigs do not secret β-glucanase to degrade the β-glucan in their feed. The indigestible β-glucan not only blocks the release of nutrients from the grain cell wall, but also increases the digesta viscosity in the gastrointestinal tract of pigs. Therefore, dietary β-glucan significantly inhibits nutrient digestion and absorption in pigs. Transgenic expression of β-glucanase in the digestive tract of pigs may offer a solution to solve this problem. In the current study, four artificial codon-optimized β-glucanases genes was prepared and expressed in porcine cells. Only p Bg A and p Egx showed high activity in transfected pig kidney cells. To improve the p H range and p H stability of β-glucanase, the two β-glucanases, p Bg A and p Egx, were co-expressed in pig kidney cells and salivary gland cells by linker A3 or 2A peptide. The resulting dual enzymes of p Bg A3 p Eg and p Bg2 Ap Eg showed significantly enlarged p H range and significantly increased p H stability, as compared to parental enzymes. These results provide useful data for future study on increasing the feed digestibility of pigs by transgenic expression of β-glucanase in their salivary glands.

关键词： β-glucanase bicistronic pig feed digestibility salivary gland cells transgenic

Inhibition of KU70 and KU80 by CRISPR interference,not NgAgo interference,increases the efficiency of homologous recombination in pig fetal fibroblasts

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Journal of Integrative Agriculture 2019年第2期18卷 438-448页

作者： li Guo-ling QUAN Rong WANG Hao-qiang RUAN Xiao-fang MO Jian-xin ZHONG Cui-li YANG Huaqiang li zi-cong GU Ting liU De-wu WU Zhen-fang CAI Geng-yuan ZHANG Xian-wei National Engineering Research Center for Breeding Swine Industry College of Animal ScienceSouth China Agricultural UniversityGuangzhou 510642P.R.China Wens Foodstuff Group Co. Ltd.Yunfu 527400P.R.China

Non-homologous end-joining(NHEJ) is a predominant pathway for the repair of DNA double-strand breaks(DSB). It inhibits the efficiency of homologous recombination(HR) by competing for DSB targets. To improve the efficiency of HR, multiple CRISPR interference(CRISPRi) and Natronobacterium gregoryi Argonaute(NgAgo) interference(NgAgoi) systems have been designed for the knockdown of NHEJ key molecules, KU70, KU80, polynucleotide kinase/phosphatase(PNKP), DNA ligase IV(liG4), and NHEJ1. Suppression of KU70 and KU80 by CRISPRi dramatically promoted(PliG4, and NHEJ1 repair factors did not significantly increase(P>0.05) HR efficiency. Interestingly, although the NgAgoi system significantly suppressed(PliG4, and NHEJ1 expression, it did not improve(P>0.05) HR efficiency in primary fetal fibroblasts. Our result showed that both NgAgo and catalytically inactive Cas9(dCas9) could interfere with the expression of target genes, but the downstream factors appear to be more active following CRISPR-mediated interference than that of NgAgo.

关键词： homologous recombination non-homologous end-joining CRISPRi NgAgoi KU70 KU80

Chinese Medicine Combined with Adjuvant Chemotherapy for Improving Myelosuppression in Colorectal Cancer Patients: A Systematic Review and Network Meta-Analysis

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Chinese Journal of Integrative Medicine 2024年第7期30卷 643-652页

作者： li Rui ZHANG Tong YAN Shao-hua YAN Yun-zi DING Ya-cong WANG Yan-song YANG Yu-fei Department of Oncology China Academy of Chinese Medical Sciences Xiyuan Hospital Department of Oncology Dongfang Hospital Beijing University of Chinese Medicine Graduate School Beijing University of Chinese Medicine

Objective: To assess the effectiveness of Chinese herbal medicine(CHM) combined with adjuvant chemotherapy on myelosuppression for colorectal cancer(CRC) patients using network meta-analysis(NMA). Methods: literature searches in both international(PubMed, Embase, Web of Science, and Cochrane library) and Chinese(China Science and Technology Journal Database, Wanfang Data, China National Knowledge Infrastructure) databases for relevant randomized controlled trials(RCTs) were conducted from inception until October 10, 2022. We included RCTs of patients who received CHM combined with chemotherapy, including FOLFOX, XELOX, FOLFIRI, and other relevant regimens in the CHM treatment group. The outcomes included the incidence of myelosuppression, leukopenia, hemoglobin reduction, and thrombocytopenia. Two reviewers independently screened the databases, extracted the data, and assessed the risk of bias and credibility of evidence. RevMan 5.4.1 software and STATA 14.0 were used to perform the NMA. Results: A total of 31 RCTs were included, published from 2008 to 2021 in Chinese. Among these, 2,314 participants comparing the following 9 CHMs were identified: Shengbai Recipe(SBR), Bazhen Decoction(BZD), Jianpi Jiedu Recipe(JJR), Jianpi Recipe(JR), Compound Cantharis Capsule(CCC), Zaofan Pill(ZFP), Guilu Erxian Gel(GL), Buzhong Tiaogan Decoction(BZ), and Qiamagu Capsule(QM). The results of NMA found an indirect comparison. Based on the surface under the cumulative ranking curve(SUCRA), the ZFP+ chemotherapy group had the lowest incidence of myelosuppression, with an odds ratio(OR) of 0.08 [95% confidence interval(CI): 0.01, 0.76], whereas the GL+ chemotherapy group had the lowest incidence of leukopenia, hemoglobin reduction, and thrombocytopenia, with an OR of 5.25(95% CI: 2.41, 11.43), 4.66(95% CI: 2.23, 9.72), and 0.27(95% CI: 0.13, 0.54), respectively. Moreover, BZD + chemotherapy could alleviate leukopenia, hemoglobin reduction, and thrombocytopenia(P<0.01). Pairwise comparison showed that there was no difference in the

关键词： Chinese herbal medicine colorectal cancer network meta-analysis systematic review myelosuppression chemotherapy

Boosting Hydrogen Storage Performance of MgH_(2) by Oxygen Vacancy-Rich H-V_(2)O_(5) Nanosheet as an Excited H-Pump

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Nano-Micro Letters 2024年第8期16卷 398-416页

作者： li Ren Yinghui li zi li Xi lin Chong Lu Wenjiang Ding Jianxin Zou National Engineering Research Center of light Alloys Net Forming&State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Shanghai Engineering Research Center of Mg Materials and Applications&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Center of Hydrogen Science Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Instrumental Analysis Center of SJTU Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

MgH_(2) is a promising high-capacity solid-state hydrogen storage material,while its application is greatly hindered by the high desorption temperature and sluggish kinetics.Herein,intertwined 2D oxygen vacancy-rich V_(2)O_(5) nanosheets(H-V_(2)O_(5))are specifically designed and used as catalysts to improve the hydrogen storage properties of MgH_(2).The as-prepared MgH_(2)-H-V_(2)O_(5) composites exhibit low desorption temperatures(Tonset=185℃)with a hydrogen capacity of 6.54 wt%,fast kinetics(Ea=84.55±1.37 kJ mol^(-1) H_(2) for desorption),and long cycling stability.Impressively,hydrogen absorption can be achieved at a temperature as low as 30℃ with a capacity of 2.38 wt%within 60 min.Moreover,the composites maintain a capacity retention rate of~99%after 100 cycles at 275℃.Experimental studies and theoretical calculations demonstrate that the in-situ formed VH_(2)/V catalysts,unique 2D structure of H-V_(2)O_(5) nanosheets,and abundant oxygen vacancies positively contribute to the improved hydrogen sorption properties.Notably,the existence of oxygen vacancies plays a double role,which could not only directly accelerate the hydrogen ab/de-sorption rate of MgH_(2),but also indirectly affect the activity of the catalytic phase VH_(2)/V,thereby further boosting the hydrogen storage performance of MgH_(2).This work highlights an oxygen vacancy excited“hydrogen pump”effect of VH_(2)/V on the hydrogen sorption of Mg/MgH_(2).The strategy developed here may pave a new way toward the development of oxygen vacancy-rich transition metal oxides catalyzed hydride systems.

关键词： Hydrogen storage MgH_(2) V_(2)O_(5)nanosheets Oxygen vacancies VH_(2)

Semi-supervised remote sensing image scene classification with prototype-based consistency

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Chinese Journal of Aeronautics 2024年第2期37卷 459-470页

作者： Yang li Zhang li zi WANG Kun WANG Qifeng YU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Deep learning significantly improves the accuracy of remote sensing image scene classification,benefiting from the large-scale datasets.However,annotating the remote sensing images is time-consuming and even tough for experts.Deep neural networks trained using a few labeled samples usually generalize less to new unseen images.In this paper,we propose a semi-supervised approach for remote sensing image scene classification based on the prototype-based consistency,by exploring massive unlabeled images.To this end,we,first,propose a feature enhancement module to extract discriminative features.This is achieved by focusing the model on the foreground areas.Then,the prototype-based classifier is introduced to the framework,which is used to acquire consistent feature representations.We conduct a series of experiments on NWPU-RESISC45 and Aerial Image Dataset(AID).Our method improves the State-Of-The-Art(SOTA)method on NWPU-RESISC45 from 92.03%to 93.08%and on AID from 94.25%to 95.24%in terms of accuracy.

关键词： Semi-supervised learning Remote sensing Scene classification Prototype network Deep learning

Nonreciprocal generation of Schrodinger cat state induced by topology

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 23-30页

作者： zi-Hao li li-li Zheng Ying Wu Xin-You Lü School of Physics and Institute for Quantum Science and Engineering Huazhong University of Science and Technologyand Wuhan Institute of Quantum TechnologyWuhan 430074China Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education Jianghan UniversityWuhan 430074China

The Schrodinger cat state produced differently in two directions is anticipated to be a critical quantum resource in quantum information technologies.By exploring the interplay between quantum nonreciprocity and topology in a one-dimensional microcavity array,we obtain the Schrodinger cat state(a pure quantum state)in a chosen direction at the edge cavity,whereas a classical state in the other direction.This nonreciprocal generation of the cat state originates from the topologically protected chiralitymode excitation in the nontrivial phase,but in the trivial phase,the nonreciprocal generation of cat state vanishes.Thus,our proposal is switchable by tuning the parameters so that a topological phase transition occurs.Moreover,the obtained cat state has nonreciprocal high fidelity,nonclassicality,and quantum coherence,which are sufficient to be used in various one-way quantum technologies,e.g.,invisible quantum sensing,noise-tolerant quantum computing,and chiral quantum networks.Our work provides a general approach to control quantum nonreciprocities with the topological effect,which substantially broadens the fields of nonreciprocal photonics and topological physics.

关键词： Schr?dinger cat state nonreciprocity topology

A Study of the Effect of the Miller Cycle on the Combustion of a Supercharged Marine Diesel Engine

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Energy Engineering 2024年第5期121卷 1363-1380页

作者： lingjie Zhao cong li Mechanical and Automotive Engineering School Shanghai University of Engineering ScienceShanghai201600China

The Miller cycle is a program that effectively reduces NOx emissions from marine diesel engines by lowering the maximum combustion temperature in the cylinder,thereby reducing NOx emissions.To effectively investigate the impact of Miller cycle optimum combustion performance and emission capability under high load conditions,this study will perform a one-dimensional simulation of the performance of a marine diesel engine,as well as a threedimensional simulation of the combustion in the cylinder.A 6-cylinder four-stroke single-stage supercharged diesel engine is taken as the research object.The chassis dynamometer and other related equipment are used to build the test system,carry out the diesel engine bench test,and collect experimental data.The simulation results are compared with the test results,and the error is less than 5%.In this study,the authors will use simulation software to simulate several Miller cycle scenarios designed for early inlet valve closure and analyze the impact of the Miller cycle on combustion and emissions at 100%load conditions.By comparing the flow field distribution of the engine at 1500 r/min condition,it was found that proper EIVC can prolong the ignition latency period and homogeneous fuel-air mixture combustion acceleration,but it can reduce pressure and temperature within the piston chamber and NOx emission.However,the Miller cycle reduces end-of-compression temperatures,which increases combustion duration and exhaust temperatures,making it difficult to improve fuel economy at the optimum fuel consumption point,and closing the intake valves prematurely leads to excessive fuel expenditure.Furthermore,temperature and heat release rate within the piston chamber,NOx,and SOOT generation were significantly enhanced.

关键词： Miller cycle EIVC combustion NOx emissions marine diesel

Detection of Pb in Tieguanyin tea and ash by laser-induced breakdown spectroscopy

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Optoelectronics Letters 2024年第2期20卷 116-121页

作者： li Jingwen YAO lixing SHEN li WANG cong Tianjin Key Laboratory of Quantum Optics and Intelligent Photonics School of ScienceTianjin University of TechnologyTianjin 300384China1

In this work, laser-induced breakdown spectroscopy(liBS) was applied for the detection of Pb in Tieguanyin tea and ash. Firstly, the Tieguanyin tea and ash containing Pb were prepared, and the difference of intensities of Pb I spectral lines before and after the ashing treatment was studied. It was found that the intensities of Pb I lines increased by 30 times and the standard deviation of background signal decreased by 41% after the ashing treatment. Therefore, the enrichment of Pb element by ashing treatment was used to detect Pb in tea with high sensitivity. Then, the calibration curve of Pb was established using spectral lines without self-absorption, and the determination coefficient(R^(2)) for the linear fitting of calibration curve was 0.979 9. Finally, it was found that the limit of detection of Pb was 233.8 ppb. Compared with the results of other works which detect Pb directly, the enrichment of Pb by ashing treatment improved the detection sensitivity of Pb by about 200 times. In addition, this method can be applied to the high sensitivity detection of other heavy metals, such as Cr, Cd, Hg, etc in plants, Chinese herbal medicine, flour, rice, coal and other solid materials.

关键词： breakdown spectroscopy treatment

Modulation of d-orbital to realize enriched electronic cobalt sites in cobalt sulfide for enhanced hydrogen evolution in electrocatalytic water/seawater splitting

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Rare Metals 2024年第2期43卷 511-521页

作者： Jian-Peng Sun Yu Zheng zi-Sheng Zhang Xiang-Chao Meng zi-Zhen li Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao266100China Shanxi Institute of Energy Taiyuan030600China Department of Chemical and Biological Engineering Faculty of EngineeringUniversity of OttawaOttawaONK1N6 N5Canada

Herein,a novel single-atomic Pt doping and interface-rich CoS/Co(OH)_(2)(Pt-CoS/Co(OH)_(2)/C)electrocatalyst has been successfully prepared.Benefiting from precise regulation of d-orbital electronic structure modulation on Co site,Pt-CoS/Co(OH)_(2)/C exhibited remarkable HER activity and high stability for hydrogen evolution in splitting both water(73 mV@10 mA·cm^(−2)) and seawater(87 mV@10 mA·cm^(−2)).Notably,atomic Pt doping was introduced into CoS/Co(OH)_(2),which could produce local unbalanced Coulombic force and significantly increased the number of S vacancies,and then expose abundant Co sites.Meantime,Co(OH)_(2) in Pt-CoS/Co(OH)_(2)/C could act as the adsorption sites for H_(2)O in hydrogen evolution reaction process.Density functional theory results also proved that atomic Pt doping,S vacancies and Co(OH)_(2) coupling could result in the formation of enriched electronic Co sites and optimize d_(z2) orbital electronic structure,and then realize the depth upward shift of d-band center and enhance the adsorption of H*on Co sites.

关键词： Electrocatalysts Hydrogen evolution reaction Pt-CoS/Co(OH)_(2) d-band center Electronic structure Water/seawater electrolysis