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Determination of trace Pb(II), Cd(II) and Zn(II) using differential pulse stripping voltammetry without Hg modification

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Science China Chemistry 2013年第12期56卷 1749-1756页

作者： lin Qi lin hongmei ZHANG YuanHui RONG MingCong KE HuiXian TANG XinHua CHEN Xi Key Lab of Global Change and Marine-Atmospheric Chemistry SOA Third Institute of Oceanography SOA Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen Standard Scientific Instrument Co. Ltd.

In this work,we reported a simultaneous determination approach for Pb(II),Cd(II)and Zn(II)atμg L 1concentration levels using differential pulse stripping voltammetry on a bismuth film electrode(BiFE).The BiFE could be prepared in situ when the sample solution contained a suitable amount of Bi(NO)3,and its analytical performance was evaluated for the simultaneous determination of Pb(II),Cd(II)and Zn(II)in *** determination limits were found to be 0.19μg L 1for Zn(II),and0.28μg L 1for Pb(II)and Cd(II),with a preconcentration time of 300 *** BiFE approach was successfully applied to determine Pb(II),Cd(II)and Zn(II)in tea leaf and infusion samples,and the results were in agreement with those obtained using an atomic absorption spectrometry *** Hg usage,the in situ preparation for BiFE supplied a green and acceptability sensitive method for the determination of the heavy metal ions.

关键词： bismuth film electrode differential pulse stripping voltammetry tea leaves tea infusion

Brain-derived neurotrophic factor expression is higher in brain tissue from patients with refractory epilepsy than in normal controls

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Neural Regeneration Research 2011年第29期6卷 2262-2266页

作者： Yudan Lv Jiqing Qiu Zan Wang Li Cui hongmei Meng Weihong lin Department of Neurology First Hospital of Jilin University Changchun 130021 Jifin Province China

The role of the brain-derived neurotrophic factor in epilepsy remains controversial. The present study utilized light and electron microscopy to investigate pathological and ultrastructural changes in brain tissue obtained from the seizure foci of 24 patients with temporal epilepsy. We found that epileptic tissue showed neuronal degeneration, glial cell proliferation, nuclear vacuolization, and neural cell tropism. Immunoelectron microscopy and immunohistochemistry showed that brain-derived neurotrophic factor was expressed at significantly higher levels in patients with refractory temporal epilepsy compared with normal controls, demonstrating that the pathological changes within seizure foci in patients with refractory epilepsy are associated with brain-derived neurotrophic factor expression alterations.

关键词： refractory epilepsy brain-derived neurotrophic factor seizure focus brain injury neural regeneration

Neuronal injury and brain-derived neurotrophic factor expression in a rat model of amygdala kindling seizures Differences in brain regions and kindling courses

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Neural Regeneration Research 2010年第8期5卷 585-590页

作者： Weihong lin hongmei Meng Yudan Lv Zan Wang Na Li Li Cui Baimin Zhang Department of Neurology First Hospital of Jilin UniversityChangchun 130021Jilin ProvinceChina

BACKGROUND：Studies have demonstrated that brain-derived neurotrophic factor （BDNF） has a dual effect on epilepsy. However, the relationship between epilepsy-induced brain injury and BDNF remains poorly ***：According to ultrastructural and molecular parameters, to detect the degree of neuronal injury and BDNF expression changes at different brain regions and different kindling times to determine the effects of BDNF on epilepsy-induced brain ***, TIME AND SETTING：A randomized, controlled, animal experiment based on neuropathology and molecular biology was performed at the Department of Physiology and Department of Pathology, Basic Medical College of Jilin University in ***：UltraSensitiveTM SP kit for immunohistochemistry （Fuzhou Maxim Biotechnology, China）, BDNF antibody （concentrated type, Wuhan Boster Biological Technology, China）, JEM-1000SX transmission electron microscopy （JEOL, Japan）, and BH-2 light microscope （Olympus, Japan） were used in the present ***：Wistar rats were randomly assigned to control （n = 6）, sham-surgery （n = 6）, and model （n = 60） groups. The control group rats were not treated; an electrode was embedded into the amygdala in rats from the sham-surgery and model groups; an amygdala kindling epilepsy model was established in the model *** OUTCOME MEASURES：Pathological changes in the temporal lobe and hippocampus were observed by light and electron microscopy at 1, 3, 7, 14, and 21 days following kindling, and BDNF expression in the various brain regions was determined by ***：In the model group, temporal lobe cortical and hippocampal neurons were swollen and the nuclei were laterally deviated. There were also some apoptotic neurons 3 days after kindling. The nucleoli disappeared and the nuclei appeared broken or lysed, as well as slight microglia hyperplasia, at 7 days. Electron microscopic observation displayed chromatin aggregation in the nuclei and slight mitochon

关键词： epilepsy brain injury brain-derived neurotrophic factor kindling brain regions rats neuronal injury neural regeneration

The underlying mechanism of variety–water–nitrogen–stubble damage interactions on yield formation in ratoon rice with low stubble height under mechanized harvesting

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Journal of Integrative Agriculture 2024年第3期23卷 806-823页

作者： Jingnan Zou Ziqin Pang Zhou Li Chunlin Guo hongmei lin Zheng Li Hongfei Chen Jinwen Huang Ting Chen Hailong Xu Bin Qin Puleng Letuma Weiwei lin Wenxiong lin College of Life Sciences Fujian Agriculture and Forestry University(FAFU)/Fujian Key Laboratory for Agroecological Processes and Safety MonitoringFuzhou 350002China College of Agriculture FAFU/Fujian Key Laboratory for Crop Physiology and Molecular EcologyFuzhou 350002China Institute of Oceanography College of Geography and OceanographyMinjiang UniversityFuzhou 350108China Crop Science Department The National University of LesothoRoma 00100Lesotho The Agricultural Extension Station of Pucheng County Nanping 353400China

Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to *** treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble *** to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice

关键词： mechanized harvesting ratoon rice rice stubble yield attributes

Characteristics and origin of mafic and ultramafic xenoliths in trachyandesite lavas from Heikongshan volcano,Tengchong,Yunnan Province,China

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Science China Earth Sciences 2010年第9期53卷 1295-1306页

作者： YU hongmei, lin ChuanYong, SHI LanBin, XU JianDong & CHEN XiaoDe Institute of Geology, China Earthquake Administration, Beijing 100029, China Institute of Geology China Earthquake Administration Beijing China

The trachyandesite lavas from Heikongshan volcano of the Tengchong volcanic cluster, Yunnan Province contain relatively abundant mafic and ultramafic small xenoliths comprising mainly gabbro, pyroxenite and rare lherzolites, all less than 2.5 cm in size. Gabbro xenoliths are characterized by "open" texture represented by relatively abundant vesicles and ground-mass fillings, while pyroxenite xenoliths are characterized by equigranular and poikilitic texture. Their mineral compositions (clinopyroxene ± orthopyroxene ± plagioclase) are similar to those of phenocrysts in lavas, and their equilibration temperature (1000-1125°C) is consistent with the crystallization temperature of the phenocrysts (998-1108°C). Thus, the textures and compositions of these xenoliths are different from those of lower crustal and mantle xenoliths, and were derived from the magma chamber. Among them, the gabbroic xenoliths come from the crystal-bubble-liquid zone at the top of the magma reservoir, while the pyroxenite xenoliths come from the cumulates in the bottom of magma reservoir. The studied single lherzolite xenolith with porphyroclastic texture has similar mineral compositions to the mantle xenoliths from eastern China, and is considered to be of upper mantle origin. It was brought into magma reservoir by replenishment magma, and might have experienced a cooling event before eruption. The formation of xenoliths in trachyandesite flows largely reflects the ascent, storage, evolution and eruption processes of magma.

关键词： magma chamber xenoliths geothermo-barometry trachyandesite Heikongshan volcano Tengchong

Solidification behavior of SiC_w/Al-18Si composites

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Rare Metals 2007年第S1期26卷 237-241页

作者： WEI hongmei,GENG lin,and ZHANG Xuexi School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

SiCw/Al-18Si composites were prepared by squeeze casting *** behavior of SiCw/Al-18Si composites was studied by differential scanning calorimeter(DSC) and scanning electron microscopy(SEM).The re-melting temperature has little effect on the solidification behavior and microstructure of *** the increase of SiC whisker content,onset and peak temperatures of primary Si decrease and the average size of primary silicon becomes smaller and *** addition lowers onset and peak temperatures of primary Si,however,onset and peak temperatures of eutectic were barely affected by Sr *** average sizes of primary Si and Al-Si eutectic both decrease by Sr addition.

关键词： SiC_w/Al-18Si composites DSC solidification microstructure

Robust Inference for Censored Quantile Regression

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Journal of Systems Science & Complexity 2024年

作者： TANG Yuanyuan WANG Xiaorui ZHU Jianming lin hongmei TANG Yanlin TONG Tiejun School of Statistics and Information Shanghai University of International Business and Economics Department of Statistics and Data Science Southern University of Science and Technology School of Statistics KLATASDS-MOE East China Normal University Department of Mathematics Hong Kong Baptist University

In various fields such as medical science and finance, it is not uncommon that the data are heavy-tailed and/or not fully observed, calling for robust inference methods that can deal with the outliers and incompleteness efficiently. In this paper, the authors propose a rank score test for quantile regression with fixed censored responses, based on the standard quantile regression in an informative subset which is computationally efficient and robust. The authors further select the informative subset by the multiply robust propensity scores, and then derive the asymptotic properties of the proposed test statistic under both the null and local alternatives. Moreover, the authors conduct extensive simulations to verify the validity of the proposed test, and apply it to a human immunodeficiency virus data set to identify the important predictors for the conditional quantiles of the censored viral load.

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Characteristics of trace metals in marine aerosols and their source identification over the Southern Ocean

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Advances in Polar Science 2015年第3期26卷 203-214页

作者： ZHAO Shuhui CHEN Liqi lin hongmei Key Lab of Global Change and Marine Atmospheric Chemistry SOA Third Institute of OceanographyState Oceanic Administration

Atmospheric trace metals （Cu, Zn, Cd, Pb, Fe, V, and Cr）, As, A1 and Na in marine aerosols were studied over the Southern Ocean during the 28th Chinese National Antarctic Research Expedition. Fe was the most abundant of the analyzed trace metals, with an average concentration of 28.824 ng.m3. V and Zn concentrations were also high, and their average concentrations were 5.541 ng.m^3 and 2.584 ng.m^-3, respectively. Although sea spray significantly influenced the marine aerosol particles measured （Na had the highest concentrations of the analyzed elements, with an average concentration of 2.65 μg.m^-3）, multivariate analyses （enrichment factor and principal components analysis） indicated that most of the elements were not associated with oceanic sources. Over the Southern Ocean, Fe, Cd, As, AI and Cr in the aerosols mainly originated from crustal sources, while Cu, Pb, V and Zn originated from crustal sources and anthropogenic emissions. The enrichment factors （EFcrust） for most elements （Fe, Al, As, Cr, Cd, Cu and V） were much lower in the northern latitudes, indicating that when the sampling occurred closer to land the concentrations of these elements in aerosols were strongly affected by terrestrial crustal sources.

关键词： aerosol trace element multivariate analysis Southern Ocean marine

Liquid-liquid extraction pretreatment samples method used for pharmacokinetic study of rhubarb in rats after oral administrated

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Journal of Traditional Chinese Medical Sciences 2018年第3期5卷 291-301页

作者： hongmei lin Longfei lin lingyan Xu Yuanping Xie Zhenzhen Xia Qing Wu Department of TCM Pharmaceutics School of Chinese Materia MedicaBeijing University of Chinese MedicineBeijingChina Institute of Chinese Materia Medica China Academy of Chinese Medical SciencesBeijingChina

Objective:Pretreatment of biological samples is the most critical step in pharmacokinetic studies,especially pre-treatment of plasma *** pretreatment of biological samples in pharmacokinetic study of Traditional Chinese Medicines (TCM) is difficult due to the complexity of the *** organic solvent system ethyl acetate:acetone (10:1) solution used for liquid-liquid extraction has been developed in this study and compared with the commonly used protein precipitation ***:Rats,Beagle dogs and humans plasma samples were adopted in this study in order to demonstrate the universality of the pretreatment *** of this pretreatment method was also verified through its application to the pharmacokinetics of rhubarb in ***:According to the results of extraction recovery matrix effect,it was indicated that the liquid-liquid extraction methods with new organic solvent might be suitable for variety of structures of compounds and various types of plasma *** pharmacokinetic study result showed that the developed pretreatment method could successfully be used for simultaneous determination of three active compounds modin,emodin-8-O-β-D-glucopyranoside (EDG) and rhein in rat plasma with high sensitivity,accuracy,and recovery by liquid chromatography tandem mass spectrometry (LC-MS/MS).Conclusion:The pretreatment method of liquid-liquid extraction methods with new organic solvent could be successfully applied for multi-component pharmacokinetics of TCM.

关键词： Pretreatment method Liquid-liquid extraction Protein precipitation LC-MS/MS Rhubarb