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A novel storage and extraction method using solid-phase adsorption and ultrasonic-assisted nebulization extraction coupled to solid phase extraction

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ANALYTICAL METHODS 2017年第33期9卷 4863-4872页

作者： Zhang, Peixu li, xuwen Cui, li Chen, Jiafeng Qu, Yan Wang, Xiaozhong Wu, Qian liu, Ying Zhou, Chunkui Jin, Yongri Jilin Univ Hosp 1 Dept Neurol Changchun 130031 Jilin Peoples R China Jilin Univ Coll Chem Changchun 130021 Jilin Peoples R China Jilin Women & Children Hlth Hosp Blood Bank Changchun 130021 Jilin Peoples R China

A novel storage and extraction method was developed for biofluids. Plasma spiked with four types of minor ginsenosides (Rg(2), Rg(3), Rh-1 and Rh-2) was used as a model biofluid to evaluate this method. The method was based on solid-phase adsorption and ultrasonic-assisted nebulization coupled with solid phase extraction (SPA-UANE-SPE). Diatomaceous earth was used as an adsorbent to store the plasma for long periods of time at room temperature. Ultrasonic-assisted nebulization system-solid phase extraction was used to extract the four minor ginsenosides from the plasma. Some experimental parameters, such as the type and amount of the adsorbent, the ultrasonic-assisted nebulization extraction time, the pH of the extraction solution, the concentration of ZnSO4, the amount of C-18, and the type and volume of the eluent were investigated and optimized. Under the optimized conditions, the recoveries of four minor ginsenosides were in the range of 78.5-91.4%, and the RSDs are in the range of 3.5-4.4%. For the storage stability test, the stability of the method was better than that of 4 degrees C storage and was similar to that of -20 degrees C storage. Compared with other methods, the proposed method had a better extraction performance and was advantageous in terms of ease of operation, stable long term storage, and minimal requirements for storage conditions. Thus, this method may be effective for sample preparation in biofluid analysis.

关键词： Extraction

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A graphene modified anode to improve the performance of microbial fuel cells

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JOURNAL OF POWER SOURCES 2011年第13期196卷 5402-5407页

作者： Zhang, Yezhen Mo, Guangquan li, xuwen Zhang, Weide Zhang, Jiaqi Ye, Jianshan Huang, Xiaodan Yu, Chengzhong S China Univ Technol Sch Chem & Chem Engn Guangzhou 510641 Peoples R China Tianjin Univ Technol Sch Environm Sci & Safety Engn Tianjin 300071 Peoples R China Fudan Univ Dept Chem Shanghai 200433 Peoples R China Fudan Univ Shanghai Key Lab Mol Catalysis & Innovat Mat Shanghai 200433 Peoples R China Univ Queensland ARC Ctr Excellence Funct Nanomat Brisbane Qld 4072 Australia Univ Queensland Australian Inst Bioengn & Nanotechnol Brisbane Qld 4072 Australia

Graphene with a Brunauer similar to Emmett-Teller (BET) specific surface area of 264 m(2) g(-1) has been used as anodic catalyst of microbial fuel cells (MFCs) based on Escherichia coli (ATCC 25922). The electrochemical activities of plain stainless steel mesh (SSM), polytetrafluoroethylene (PTFE) modified SSM (PMS) and graphene modified SSM (GMS) have been investigated by cyclic voltammetry (CV), discharge experiment and polarization curve measurement. The GMS shows better electrochemical performance than those of SSM and PMS. The MFC equipped with GMS anode delivers a maximum power density of 2668 mW m(-2), which is 18 times larger than that obtained from the MFC with the SSM anode and is 17 times larger than that obtained from the MFC with the PMS anode. Scanning electron microscopy (SEM) results indicate that the increase in power generation could be attributed to the high surface area of anode and an increase in the number of bacteria attached to anode. (C) 2011 Elsevier B.V. All rights reserved.

关键词： Graphene Biocatalyst Microbial fuel cells

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Design of Wide-Range High-Precision Cesium Oven Temperature Control System for Time-Keeping Cesium Beam Frequency Standards

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APPliED SCIENCES-BASEL 2025年第3期15卷 1128-1128页

作者： liu, Jie li, Xiaofeng li, Chao Hu, xuwen li, Qingyue Sun, Fuyu Zhang, Shougang Chinese Acad Sci Natl Time Serv Ctr 3 East Shuyuan Rd Xian 710600 Peoples R China Nanchang Univ Sch Phys & Mat Sci Nanchang 330031 Peoples R China Chinese Acad Sci Key Lab Time Reference & Applicat 3 East Shuyuan Rd Xian 710600 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

The temperature fluctuation of a cesium oven has a significant impact on the performance of time-keeping cesium beam frequency standards. We have designed a circuit system for the precise temperature control of the cesium oven used in it. The use of a 24-bit analog-to-digital converter ensures a temperature measurement resolution more than 0.5 mK within the working range. The digital PID algorithm guarantees the accuracy of error signal computation, and a 16-bit digital-to-analog converter improves the resolution of the control current adjustment. Ultimately, we achieved the goal of keeping the temperature fluctuation of the cesium oven to less than 4 mK within a working range of 120 degrees C. The results indicate that the circuit system effectively ensures the performance of the cesium beam frequency standard.

关键词： time-keeping cesium beam frequency standards cesium oven temperature control digital PID

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Research of the assessable method of postpartum hemorrhage

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TECHNOLOGY AND HEALTH CARE 2016年第Suppl 2期24卷 S465-S469页

作者： Chi, Zhenyu Zhang, Song Wang, Yang Yang, lin Yang, Yimin li, xuwen Beijing Univ Technol Coll Life Sci & Bioengn Beijing Peoples R China Shenzhen Huada Gene Res Inst Shenzhen Guangdong Peoples R China

BACKGROUND: Postpartum hemorrhage (PPH) is the most common cause of parturient death worldwide [1]. However, most cases of PPH can be avoided. OBJECTIVE: This paper employs statistical methods to screen risk factors of PPH and calculate relevant parameters. METHODS: Multivariable logistic regression analysis was applied to obtain the regression equation and odds ratio (OR) value. The determined risk factors were assigned comprehensive and reasonable scores according to scientific relevance and reasoning according to the OR value. P-PPH values were calculated in order to assess the morbidity of PPH. RESULTS: The scores of pregnant women could be intuitively used to show the risk of getting PPH. CONCLUSIONS: Through the above methods, a comprehensive risk evaluation method of detecting PPH was developed.

关键词： Postpartum hemorrhage high risk factors comprehensive scores

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Selective Frustrated/Nonfrustrated Anion-Migrated Ring-Opening Polymerization of 1-Cyclopropylvinylbenzene

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MACROMOLECULES 2022年第12期55卷 5140-5148页

作者： Bai, Hongyuan Wang, Yinran Han, li Wang, Xuefei Yan, Hong li, xuwen Chen, Siwei Leng, Haitao Yao, Zijing Ma, Hongwei Dalian Univ Technol Sch Chem Engn Dept Polymer Sci & Engn Dalian 116024 Peoples R China

Exploring novel polymerization mechanisms for the preparation of switchable isomers in chains from homopolymerization with only monomers is undoubtedly an exhilarating and challenging pursuit in polymer chemistry. Therefore, this work presents a novel strategy for realizing reversible cycle anion migrated ring-opening polymerization (AMROP) and general anionic polymerization (thermodynamics limits the further ring-opening reaction of the 1-cyclopropylvinylbenzene (CPVB) unit, and this process is defined as frustrated AMROP). By employing alkali metal alkoxides (potassium tert-butoxide (t-BuOK) and sodium 2,3-dimethylpentan-3-olate (NaODP)) as additives, the opening of the cyclopropyl group in CPVB can be controlled during homopolymerization. Additionally, the structure and sequence distribution of inserted CPVB units are determined by distinct selective polymerization mechanisms. Thus, the synthetic polymer includes two structural units, i.e., ring-opened CPVB (ro), which is generated from AMROP, and nonopened CPVB (ga), which results from frustrated AMROP (F-AMROP). Furthermore, in view of steric hindrance from the penultimate-unit effect during chain growth of CPVB, the process of F-AMROP cannot continuously occur and requires the AMRO process of CPVB to decrease the steric hindrance around active centers. Therefor;under the influence of steric hindrance from the penultimate unit, AMRO, and thermodynamics, a reversible cycle of frustrated and nonfrustrated AMROP can be activated during the polymerization process, which further realizes a single monomer to prepare an alternating polymer with different isomers. Ultimately, the mechanisms for AMROP and F-AMROP are explored deeply with density functional theory calculations. This intriguing mechanistic finding will become a pioneering and innovative strategy for development of polymerization mechanisms and unprecedented polymer structures in polymer synthesis.

关键词： Additives Chemical structure Molecular structure Polymerization Polymers

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Intelligent Delivery Systems in Tumor Metabolism Regulation: Exploring the Path Ahead

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ADVANCED MATERIALS 2024年第11期36卷 2309582-2309582页

作者： li, xuwen Sun, Tao Jiang, Chen Fudan Univ Sch Pharm Dept Pharmaceut Minist EducKey Lab Smart Drug Delivery Shanghai 201203 Peoples R China MOE Frontiers Ctr Brain Sci Shanghai 201203 Peoples R China

Cancer metabolism plays multifaceted roles in the initiation and progression of tumors, and interventions in metabolism are considered fundamental approaches for cancer control. Within the vast metabolic networks of tumors, there exist numerous potential therapeutic targets, intricately interconnected with each other and with signaling networks related to immunity, metastasis, drug resistance, and more. Based on the characteristics of the tumor microenvironment, constructing drug delivery systems for multi-level modulation of the tumor microenvironment is proven as an effective strategy for achieving multidimensional control of cancer. Consequently, this article summarizes several features of tumor metabolism to provide insights into recent advancements in intelligent drug delivery systems for achieving multi-level regulation of the metabolic microenvironment in cancer, with the aim of offering a novel paradigm for cancer treatment. Latest advancements in intelligent drug delivery systems (DDS) exhibit distinctive advantages, including precise sensing, programmability, feedback control, and intrinsic activity. These attributes render them conducive to facilitating multi-dimensional therapeutic approaches grounded in metabolic ***

关键词： intelligent delivery systems metabolism regulation nanomedicine tumor metabolism

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The Pulse Waveform and Parameters Analysis of Various Athletes Based on Radial Pulse

The Pulse Waveform and Parameters Analysis of Various Athlet...

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IEEE Workshop on Electronics, Computer and Applications (IWECA)

作者： Wang, Anran li, xuwen Yang, lin Yang, Xingxing Meng, Lanxi Su, Jun Zhang, Song Beijing Univ Technol Coll Life Sci & Bioengn Beijing 100124 Peoples R China Beijing Muxiyuan Sports Tech Sch Beijing 100075 Peoples R China

ISBN: (纸本)9781479945658

Classify the sports events by the maximal oxygen uptake (MaxO(2)) and the maximal muscular voluntary contraction (MVC). Collect the radial pulse wave of different sports events and discuss the pulse waveform and characteristic parameters. Radial pulse waveform on 304 subjects was collected, by using PowerLab and its bundled software LabChart 7, developed by ADInstrument. Normalize each radial pulse waveform and let the waveform cycle and amplitude distribute in the range of 0.100. Analyze the relative time of the maximum point Tm, the abscissa X and ordinate Y of dicrotic notch, the pulse waveform area K and the pulse wave age index SDPTG. The pulse waveform changing trend of MVC (<50%) group and MVC (>50%) group are different while the sports have the same MaxO(2). And the pulse waveform changing trend of MaxO(2) (<40%) group, MaxO(2) (40%-70%) group and MaxO(2) (>70%) group are as well as different while the sports have the same MVC.

关键词： Athlete Pulse wave Radial artery Waveform parameter

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Metabolic Nanoregulators Induce Ferroptosis and Change Metabolite Flow to Reverse Immunosuppressive Tumor Microenvironment

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ACS NANO 2024年第51期18卷 34996-35012页

作者： Wang, Yu Chen, Qinjun Luo, Yifan Qu, Yangqi li, xuwen Song, Haolin li, Chufeng Zhang, Yiwen Sun, Tao Jiang, Chen Fudan Univ Key Lab Smart Drug Delivery State Key Lab Med Neurobiol Dept PharmaceutSch PharmInst Brain SciMinist Ed Shanghai 201203 Peoples R China MOE Frontiers Ctr Brain Sci Shanghai 201203 Peoples R China Fujian Med Univ Affiliated Hosp 1 Natl Reg Med Ctr Dept Digest Dis Binhai Campus Fuzhou 350212 Peoples R China

Aberrant energy and substance metabolic pathways of tumor cells critically support tumor cell proliferation by hijacking the resources from nonmalignant cells, thereby establishing a metabolite flow favorable to tumor progression. This metabolic adaptation of tumor cells further modulates the immune landscape, ultimately creating a tumor microenvironment characterized by drug resistance and immunosuppression. The synergistic regulation of energy and substance metabolic pathways might be a good antitumor therapeutic paradigm. However, due to the metabolic convergence, it is crucial to selectively modulate the aberrant metabolism of tumor cells without compromising the functionality of other cells. Small-molecule drugs have the ability to target a wide range of biomolecules for antitumor therapy, but their application is limited by undesirable toxicities. Constructing nanodrug delivery systems can improve their properties and allow for the inclusion of multiple drugs, thereby exerting synergistic antitumor effects. In this study, we developed a two-drug codelivery system using drugs-conjugated multibranched polymers to modulate tumor cell metabolism by exploiting synthetic lethal pathways for safe and effective antitumor therapy. By delivery of adapalene and erastin simultaneously through nanoparticles, the material and energy metabolism of tumor cells can be regulated. This nanoparticle construction achieves tumor tissue targeting and responsive drug release, alters metabolite flow within tumor cells, and effectively kills tumor cells. Additionally, the nanoparticles can reverse the tumor immunosuppressive microenvironment, starting from single-cell regulation to whole-lesion control.

关键词： metabolic nanoregulators metabolite flow ferroptosis immunosuppression multibranched polymers

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Analysis of heart rate variation and foetal quiet sleep cycle correlation for normal and suspicious foetuses

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BIOTECHNOLOGY & BIOTECHNOLOGICAL EQUIPMENT 2018年第4期32卷 988-992页

作者： li, Guangfei Zhang, Song Yang, lin li, Shufang Wang, Yan Zhao, Yangyu Yang, Yimin Hao, Dongmei li, xuwen Zhang, Lei Xu, Mingzhou Beijing Univ Technol Coll Life Sci & Bioengn Beijing Peoples R China Peking Univ Hosp 3 Obstet & Gynecol Beijing Peoples R China Beijing Yes Med Devices Co Ltd Beijing Peoples R China Beijing Aerosp Changfeng Co Ltd Beijing Peoples R China

Cardiotocography (CTG) is the basic method of monitoring foetal condition in the perinatal period. However, due to the limited insight into the CTG generation mechanism, some CTG recordings can be mistreated as a predictor of neonatal asphyxia, leading to a wrong assessment of the foetal status and improper obstetric intervention. Therefore, in case of suspicious CTG indications, a reliable verification of the true foetal status is vital for reducing the clinical diagnosis false-positive rate and avoiding the unnecessary obstetrician intervention. The paper presents the results obtained for 44 foetuses on the shares of three heart rate variation (HRV) ranges and quiet sleep cycles. This approach uses the parameters of the HRV range shares and quiet sleep cycles to analyse different types of foetuses. The results obtained show that most parameters reveal significant differences between normal and suspicious groups. This is quite lucrative for defining a set of coefficients, whose incorporation into a classifier will improve the accuracy of distinguishing the normal foetuses from suspicious ones.

关键词： Foetal heart rate foetal quiet sleep HRV range share

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FLAVONOIDS FROM THE LEAVES OF Actinidia kolomikta

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CHEMISTRY OF NATURAL COMPOUNDS 2010年第2期46卷 205-208页

作者： Lu, Juan Jin, Yongri liu, Guiying Zhu, Na Gui, Mingyu Yu, Aimin li, xuwen Jilin Univ Coll Chem Changchun 130021 Peoples R China Changchun Normal Univ Coll Chem Changchun 130021 Peoples R China

One new acetylated flavonoid, kaempferide-7-O-(4 ''-O-acetyl)-alpha-L-rhamnoside, and six known flavonoids were isolated from the EtOAc fraction of the leaves of Actinidia kolomikta (Rupr. et Maxim.) Planch. The chemical structures of the isolated compounds were established by application of chemical and spectroscopic analysis. The new acetylated flavonoid was screened for its protective effect on human erythrocytes against AAPH-induced hemolysis, and it can slow the hemolysis induced by AAPH.

关键词： Actinidia kolomikta Actinidiaceae acetylated flavonoid AAPH-induced hemolysis

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