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Chain Conformation and Bioactivity of Lentinan

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生物医学工程学杂志 2005年第S1期22卷 21-页

作者： Xiao-Juan XU Xu-lian li li-na zhang(department of chemistry, wuhan university, wuhan 430072,china)

Partial linear Model Averaging Prediction for Longitudinal Data

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Journal of Systems Science & Complexity 2024年第2期37卷 863-885页

作者： li na FEI Yu zhang Xinyu Faculty of Science Kunming University of Science and TechnologyKunming 650500China School of Statistics and Mathematics Yunnan University of Finance and EconomicsKunming 650221China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

Prediction plays an important role in data *** averaging method generally provides better prediction than using any of its *** though model averaging has been extensively investigated under independent errors,few authors have considered model averaging for semiparametric models with correlated *** this paper,the authors offer an optimal model averaging method to improve the prediction in partially linear model for longitudinal *** model averaging weights are obtained by minimizing criterion,which is an unbiased estimator of the expected in-sample squared error loss plus a *** properties,including asymptotic optimality and consistency of averaging weights,are established under two scenarios:(i)All candidate models are misspecified;(ii)Correct models are available in the candidate *** studies and an empirical example show that the promise of the proposed procedure over other competitive methods.

关键词： Asymptotic optimality longitudinal data model averaging estimator partially linear model prediction

SOLUTION PROPERTIES OF ANTITUMOR CARBOXYMETHYLATED DERIVATIVES OF α-(1→3)-D-GLUCAN FROM GANODERMA LUCIDUM

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Chinese Journal of Polymer Science 2001年第3期19卷 283-289页

作者： li-na zhang Mei zhang Jing-hua Chen Fan-bo Zeng department of chemistry wuhan university, wuhan 430072, china Pharmacy College, Tongji Medical university, wuhan 430072, china 武汉大学湖北武汉同济医科大学湖北武汉

Fractions of a water insoluble α-(1→3)-D-glucan (GL) extracted from Ganoderma lucidum were carboxy-methylated (CM) to obtain water-soluble carboxymethylated derivatives (CM-GL) having a degree of substitution (DS) of0.38～0.51. Weight-average molecular weight M_w and intrinsic viscosity [η] of the samples CM-GL were measured by gelpermeation chromatography combined with laser light scattering (GPC-LLS) and viscometry. The CM-GL exhibits a stifferchain in aqueous solution at 25℃ than the original glucan, The antitumor activities against Ehrlich ascites carcinoma (EAC,5×10~6) of the carboxymethylated derivatives from the α-glucan and curdlan, a β-glucan, are significantly higher than thoseof the original glucans. The effects of the relatively low molecular weight, expanded chains and better water-solubility of theCM-GL on the enhancement of antitumor activity could not be neglected. The chain stiffness decreased speedily withincrease of temperature from 40 to 60℃ or naOH concentration from 0.1 to 0.4 in the solution, respectively, and the changeof the chain stiffness is reversible.

关键词： Solution properties Antitumor activity Carboxymethylated derivative α-D-glucan Ganoderma lucidum

Exceptional points enhance sensing in silicon micromechanical resonators

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Microsystems & nanoengineering 2024年第1期10卷 17-25页

作者： Man-na zhang Lei Dong li-Feng Wang Qing-An Huang Key Laboratory of MEMS of the Ministry of Education Southeast UniversityNanjing 210096China

Exceptional points(EPs)have recently emerged as a new method for engineering the response of open physical systems,that is,systems that interact with the *** systems at the EPs exhibit a strong response to a small ***,we show a method by which the sensitivity of silicon resonant sensors can be enhanced when operated at *** our experiments,we use a pair of mechanically coupled silicon micromechanical resonators constituting a parity-time(PT)-symmetric *** perturbations introduced on the mechanically coupled spring cause the frequency to split from the EPs into the PT-symmetric regime without broadening the two spectrum linewidths,and this frequency splitting scales with the square root of the perturbation *** overall signal-tonoise ratio is still greatly enhanced,although the measured noise spectral density of the EP sensing scheme has a slight increase comparable to the traditional *** results pave the way for resonant sensors with ultrahigh sensitivity.

关键词： resonant symmetric points

Application of GNSS-PPP on Dynamic Deformation Monitoring of Offshore Platforms

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china Ocean Engineering 2024年第2期38卷 352-361页

作者： YU li-na XIONG Kuan GAO Xi-feng li Zhi FAN li-long zhang Kai Institute of Ocean Energy and Intelligent Construction Tianjin University of TechnologyTianjin 300384China china Railway Construction Bridge Engineering Bureau Group Co.LTD Tianjin 300300China School of Civil Engineering Tianjin UniversityTianjin 300072China department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong KongChina State Key Laboratory of Precision Blasting Jianghan UniversityWuhan 430056China

The real-time dynamic deformation monitoring of offshore platforms under environmental excitation is crucial to their safe *** Global navigation Satellite System-Precise Point Positioning(GNSS-PPP)has been considered for this purpose,its monitoring accuracy is relatively ***,the influence of background noise on the dynamic monitoring accuracy of GNSS-PPP remains ***,it is imperative to further validate the feasibility of GNSS-PPP for deformation monitoring of offshore *** address these concerns,vibration table tests with different amplitudes and frequencies are *** results demonstrate that GNSS-PPP can effectively monitor horizontal vibration displacement as low as±30 mm,which is consistent with ***,the spectral characteristic of background noise in GNSS-PPP is similar to that of GNSS-RTK(Real Time Kinematic).Building on this observation,an improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)has been proposed to de-noise the data and enhance the dynamic monitoring accuracy of *** monitoring application research is also undertaken,successfully extracting and analyzing the dynamic deformation of an offshore platform structure under environmental excitation using GNSS-PPP monitoring in conjunction with improved CEEMDAN *** comparing the de-noised dynamic deformation trajectories of the offshore platform during different periods,it is observed that the platform exhibits reversible alternating vibration responses under environmental excitation,with more pronounced displacement deformation in the direction of load *** research results confirm the feasibility and potential of GNSS-PPP for dynamic deformation monitoring of offshore platforms.

关键词： GNSS-PPP offshore platform dynamic deformation monitoring improved CEEMDAN de-noising

SIZE EXCLUSION CHROMATOGRAPHIC COLUMN PACKED WITH REGENERATED CELLULOSE GELS

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Chinese Journal of Polymer Science 2001年第4期19卷 415-419页

作者： Guang Yang li-na zhang Xiao-peng Xiong Xiao-dong Cao Yong-liang Yang department of chemistry wuhan university wuhan 430072, china 武汉大学湖北武汉

Microporous regenerated cellulose gel particles were prepared by mixing cellulose cuoxam with silk fibroin as pore former, and the mean pore size and pore volume of the particles were 525 nm and 7.27 mt g(-1), respectively. A preparative size-exclusion chromatography (SEC) column (550 mm x 20 mm) packed with the cellulose gel particles was used for the fractionation of two polysaccharides Dextran 07 (M-W = 7.14 x 10(4), d = 1.7) and Dextran 50 (M-W = 50.5 x 10(4), d = 3.8) in water phase. The fractionation range of the stationary phase covered M, from 3 x 10(3) to 1.1 x 10(6). The daily throughput was 2.9 g for Dextran 07 (D07) and 4.3 g for Dextran 50 (D50) with a flow-rate of 1.5 mt min(-1). The fractions obtained by using the SEC were analyzed by an analytical SEC combined with laser light scattering (LLS), and the polydispersity indices of fractions for Dextran 07 and Dextran 50 were determined to be 1.34-1.57 and 1.53-3.36, respectively. The preparative SEC is a simple, rapid, and suitable means not only for the fractionation of polysaccharides in water but also for other polymers in organic solvents.

关键词： cellulose packing silk fibroin preparative chromatography polysaccharides

Fluorescent Probes for Cysteine and Cysteine Oxidation Imaging

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Chemical Research in Chinese Universities 2024年第2期40卷 225-236页

作者： zhang Xia li Guocheng PAN Wei li na li Yanhua TANG Bo College of chemistry Chemical Engineering and Materials ScienceKey Laboratory of Molecular and Nano ProbesMinistry of EducationCollaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongInstitute of Molecular and Nano ScienceShandong Normal UniversityJinan250014P.R.China Laoshan Laboratory Qingdao266237P.R.China

Cysteine is an important regulator of redox *** to the nucleophilic and oxidative sensitivity,cysteine residues in proteins can be oxidized by intracellular reactive oxygen species(ROS),which can lead to protein structural and functional ***,the development of fluorescent probes to image cysteine and cysteine oxidation is of great significance for the study of redox homeostasis in living *** this review,the development of fluorescent probes for imaging cysteine and cysteine oxidation was ***,we further analyzed defects of the reported fluorescent probes and made suggestions for the future development of fluorescent *** expect that this review can not only provide a deeper understanding of the role of cysteine and cysteine oxidation in oxidative stress,but also broaden the application of fluorescent probes in imaging cysteine and cysteine oxidation.

关键词： Cysteine Cysteine oxidation Fluorescent probe Oxidative stress

Incubation temperature induced developmental plasticity of cold responsive physiological phenotypes in Japanese Quails

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Avian Research 2024年第3期15卷 385-394页

作者： Yingxin Kou Rongmiao zhang Xiaoqian li na Zhu Yihang Huang Shuping zhang College of life and Environmental Sciences Minzu University of ChinaBeijing100081China

Embryonic development is a critical period for phenotype *** variation during embryonic development can induce changes in postnatal phenotypes of *** thyroxine secretion and aerobic metabolic activity of small birds are important phenotypes closely related to their winter *** the context of climate change,it is necessary to determine whether temperature variation during incubation in birds leads to developmental plasticity of these cold responsive *** incubated Japanese Quail(Coturnix japonica)eggs at 36.8℃,37.8℃,and 38.8℃,and raised the chicks to 35-day old at 22℃with same raising conditions,then all the quails were exposed to gradually temperature dropping environment(from 15℃to 0℃).After cold treatment,serum T3 level,resting metabolic rate,skeletal muscle and liver metabolomes of the birds were *** serum T3 levels were significantly lower in the 38.8℃group and significantly higher in the 36.8℃group compared to the 37.8℃*** metabolic rate in the 38.8℃group was significantly lower compared to the 37.8℃*** with the 37.8℃group,metabolites involved in the tricarboxylic acid cycle in the liver were significantly lower in the 38.8℃group,and metabolites related to lipid oxidation metabolism and fatty acid biosynthesis were significantly lower in the skeletal muscles in the 38.8℃group but significantly higher in the 36.8℃*** results indicate that incubation temperature variation can lead to developmental plasticity in cold responsive physiological *** incubation temperature may impair the capacity of birds coping with cold challenge.

关键词： Cold response Developmental plasticity Incubation temperature Metabolic rate Metabolomes Precocial bird Thyroxin

Astronomical forcing and sedimentary noise modeling of lake-level changes in the Middle Eocene Chezhen Sag,Bohai Bay Basin,eastern china

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Frontiers of Earth Science 2024年第2期18卷 446-459页

作者： Xuwei LUAN Jinliang zhang na li Tao CHEN Long SUN Xuecai zhang Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China College of Geosciences China University of Petroleum(Beijing)Beijing 102249China Management Center of Oil and Gas Exploration Sinopec Shengli OilfieldDongying 257000China

The accurate determination of geological age is a key to understanding the history and process of paleolake evolution and oil and gas exploration in continental lake ***,improving the accuracy of geological age has always been a difficult scientific problem.A 609-m-thick,continuous lacustrine mudstone and sandstone succession in Chezhen Sag(eastern china)provides an ideal middle Eocene sedimentary record for establishing a high-resolution stratigraphic chronology *** on spectrum analysis and sliding window spectrum analysis of the natural gamma(GR)logging data of well Che 271(C271)in Chezhen Sag,the periods of 405 kyr and 40.1 kyr were filtered by a Gaussian bandpass filter,and a“floating”astrochronological time scale(ATS)was *** total number of 405 kyr eccentricity cycles were 13.6 and 40.1 kyr obliquity cycles were 138 which recorded from the upper member 4(Es4U)to the member 3(Es3)of the Eocene Shahejie Formation,and the depositional duration was 5.53 *** Coefficient(COCO)analysis and evolutionary Correlation Coefficient(eCoCo)analysis found that the optimal sedimentary rate of different *** noise simulation revealed the history of paleolake water changes in the Middle Eocene in the Chezhen Sag,according to which four sequences are *** study shows that the lake level change of Chezhen Sag in the middle Eocene shows prominent 1.2 Myr cycles and an antiphase well-coupled relationship with obliquity ***,we propose a model to explain the relationship between the orbital cycle and lake level change in the continental lake *** the obliquity of the earth increases,the middle and high latitudes of the earth will be closer to the sun,the direct sunlight will be higher,and the meridional sunshine will increase,thus accelerating the evaporation process of lake basin *** the seasonal changes are obvious(maximum period of 1.2 Myr ultra-long obliquity),this effect is more signific

关键词： Chezhen Sag cyclostratigraphy astrochronological time scale sedimentary noise