检索结果-南通市图书馆

Synthesis of anionic sulphonate-crown ether surfactants

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2013年第12期24卷 1137-1139页

作者： Jing Zhou He-Le Liang Qing-De Chen xing-hai shen Beijing National Laboratory for Molecular Sciences (BNLMS) Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental ScienceCollege of Chemistry and Molecular EngineeringPeking University

Two sulphonate-crown ether surfactants （sodium （4＇-dodecanoyldJbenzo-18-crown-6）-4＂（5＂）-sulpho- nate, ammonium （4＇-dodecanoyldibenzo-18-crown-6）-4＂（5＂）-sulphonate） were designed and synthesized via a two-step continuous method. The products were purified and characterized by IR. 1H NMR and elemental analysis. The physicochemical properties of the surfactants were studied by fluorescence, conductivity and dynamic light scattering techniques.

关键词： Crown ether Sulphonate Surfactant Synthesis

Preparation and characterization of single crystals[Ln(TBPO)4(NO3)2]NTf2 (Ln = Eu, Gd)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2017年第1期28卷 19-23页

作者： Chuan-Dong Deng Yu-Jia Qiao Qing-De Chen xing-hai shen Beijing National Laboratory for Molecular Sciences (BNLMS) Fundamental Science on Radiochemistry and Radiation Chemistry Laboratory College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Two single crystals [Ln（TBPO）4（NO3）2]NTf2 （Ln = Eu, Gd） were prepared and characterized by element analysis, single crystal X-ray diffraction, PXRD, FT-IR, TGA and fluorescence spectroscopy. The two compounds have similar coordinate structures, in which the central metal ion is coordinated by four TBPO（Tri-n-butylphosphine oxide） molecules and two bidentate nitrates, while NTf2^-（bis（trifluor-（bis（trifluoromethylsulfonyl）imide anion） acts as the counter anion. The packing modes of the two crystals are same. The two single crystals are the focus on 8-coordinate tetra-TRPO complexes（TRPO is Trialkyphosphine oxides）.

关键词： Tri-n-butylphosphine oxide Europium Gadolinium Single crystal

EFFECTS OF L-PHENYLALANINE ON THE RADIATION SYNTHESIS OF POLY(N,N'-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE)(MICRO)GELS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2005年第6期23卷 643-650页

作者： Qing-de Chen xing-hai shen and Hong-cheng Gao Department of Applied Chemistry,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China Department of Applied Chemistry College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

The effects of L-phenylalanine （L-Phe） on the synthesis ofpoly（N,N＇-methylenebisacrylamide-co-4-vinylpyridine）（poly（Bis-co-4-VP））（micro）gels by γ-ray irradiation were studied. The addition of L-Phe could not only decrease the gelation dose （Dg） of the synthesis obviously, but also transform the morphology of copolymer from microgel to gel. In addition, the swelling ability of the （micro）gels was also affected in the presence of L-Phe. The decrease of Dg was ascribed to the effect of pH, while the transformation of the morphology was ascribed to the effect of L-Phe on the stability of the poly（Bis-co-4-VP） microgel. Such an effect was confirmed further as compared with the effects of L-alanine, L-glutamic acid, L-arginine, sulfuric acid and aqueous ammonia.

关键词： L-Phenylalanine γ-Ray irradiation Gelation dose Morphology transformation (Micro)gel

STABILITY OF POLY(N,N'-METHYLENEBISACRYLAMIDE-co-4-VINYLPYRIDINE)MICROGEL DISPERSION AND ADJUSTMENT OF THE HYDROPHOBICITY IN THE MICROGELS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2005年第6期23卷 635-642页

In the UV-Vis spectra of pure light-scattering systems, there is an exponential relationship between absorbance and wavelength （A = Kλ^-n）. Here, the exponent n is named as flocculation-coagulation parameter. In the present paper, the effects of different additives on the stability of poly（N,N＇-methylenebisacrylamide-co-4-vinylpyridine）（poly（Bis-co-4-VP）） microgel dispersion were studied in detail via this parameter. The results showed that the stability of the dispersion mainly comes from the ionization of pyridine groups, making the microgel positively charged on its surface. This was confirmed by the measurement of Zeta potential and the result of conductometric titration. The result of fluorescence analysis indicated that the hydrophobicity in the microgels is enhanced with the increase in total 4-VP unit content.

关键词： Microgel dispersion(s) 4-Vinylpyridine Flocculation-coagulation parameter Zeta potential

Biological factors driving colorectal cancer metastasis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第2期16卷 259-272页

作者： Shuai-xing An Zhao-Jin Yu Chen Fu Min-Jie Wei Long-hai shen Department of Pharmacology School of PharmacyChina Medical UniversityShenyang 110122Liaoning ProvinceChina Liaoning Key Laboratory of Molecular Targeted Antitumor Drug Development and Evaluation Liaoning Cancer Immune Peptide Drug Engineering Technology Research CenterKey Laboratory of Precision Diagnosis and Treatment of Gastrointestinal Tumors(China Medical University)Ministry of EducationShenyang 110122Liaoning ProvinceChina BD Department Greenpine Pharma Group Co.LtdTianjin 300020China Center of Oncology Genertec Liaoyou Gem Flower HospitalPanJin 124010Liaoning ProvinceChina

Approximately 20%of colorectal cancer(CRC)patients present with metastasis at *** Stage I-III CRC patients who undergo surgical resection,18%typically suffer from distal metastasis within the first three years following initial *** median survival duration after the diagnosis of metastatic CRC(mCRC)is only 9 *** is traditionally considered to be an advanced stage malignancy or is thought to be caused by incomplete resection of tumor tissue,allowing cancer cells to spread from primary to distant organs;however,increa-sing evidence suggests that the mCRC process can begin early in tumor *** patients present with high heterogeneity and diverse cancer phenotypes that are classified on the basis of molecular and morphological *** genomic and nongenomic events can induce subclone diversity,which leads to cancer and *** the course of mCRC,metastatic cascades are associated with invasive cancer cell migration through the circulatory system,extravasation,distal seeding,dormancy,and reactivation,with each step requiring specific molecular ***,cancer cells presenting neoantigens can be recognized and eliminated by the immune *** this review,we explain the biological factors that drive CRC metastasis,namely,genomic instability,epigenetic instability,the metastatic cascade,the cancer-immunity cycle,and external lifestyle *** remarkable progress in CRC research,the role of molecular classification in therapeutic intervention remains *** review shows the driving factors of mCRC which may help in identifying potential candidate biomarkers that can improve the diagnosis and early detection of mCRC cases.

关键词： cancer Metastasis cascade Cancer immunity Genomic variation Epigenetic instability Lifestyle factor

Using Copula functions to predict climatic change impacts on floods in river source regions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第3期15卷 406-418页

作者： Ting-xing CHEN hai-shen LYU Robert HORTON Yong-Hua ZHU Ren-sheng CHEN Ming-Yue SUN Ming-Wen LIU Yu LIN The National Key Laboratory of Water Disaster Prevention College of Hydrology and Water ResourcesHohai UniversityNanjing 2098China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China Departmentof Agronomy lowa State UniversityAmes IA5oollUSA Qilian Alpine Eology and Hydrology Research Station Northwest Instiuteof Eco-Environmentand ReourcesChinese Academy of SciencesLanzhou0000 China

Flood frequency in river source regions is significantly affected by rainfall and snowmelt as part of climatic changes.A traditional univariate flood frequency analysis cannot reflect the complexity of floods,and when used in isolation,it can only underestimate flood *** effective flood prevention and mitigation,it is essential to consider the combined effects of precipitation and *** functions can effectively quantify the joint distribution relationship between floods and their associated variables without restrictions on their distribution *** study uses copula functions to consider a multivariate probability distribution model of flood peak flow(Q)with cumulative snowmelt(CSm)and cumulative precipitation(CPr)for the Hutubi River basin located in northern Xinjiang,*** joint frequencies of rainfall and snowmelt floods are predicted using copula models based on the Coupled Model Intercomparison Project Phase 6 *** results show that Q has a significant positive correlation with 24-d CSm(r=0.559,p=0.002)and 23-d CPr(r=0.965,p<0.05).Flood frequency will increase in the future,and mid-(2050e2074)and long-term(2075e2099)floods will be more severe than those in the near-term(2025e2049).The probability of flood occurrence is higher under the SSP2-4.5 and SSP1-2.6 scenarios than under *** during the historical period(1990e2014)led to extreme floods,and increasing future precipitation trends are found to be *** increases with rising temperatures and occurs earlier than estimated,leading to an earlier flood period in the basin and more frequent snowmelt *** Q under the joint return period is larger than that during the same univariate return *** difference indicates that neglecting the interaction between precipitation and snowmelt for floods leads to an underestimation of the flood risk(with underestimations ranging from 0.3%to 22%).The underestimations decrease with an increase

关键词： Climate change Flood frequency Copula CMIP6 River source regions

Effects of environment and genotype-by-environment interaction on phenotype of Rorippa elata(Brassicaceae),an endemic alpine plant in the Hengduan mountains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2024年第4期17卷 42-55页

作者： Zhi-Qiang Du Yao-Wu xing Ting-shen Han CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Plant Diversity and Specialty Crops Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China

Global climate change poses a severe threat to mountain *** plasticity and local adaptation are two common strategies for alpine plant to cope with such *** may facilitate organismal adaptation to contrasting environments,depending on the influences of the environment or genotype or their interacted *** this study,we use an endemic alpine plant(Rorippa elata)in the Hengduan mountains(HDM)to unravel its phenotypic basis of adaptation strategy and evaluate the relative contributions of environment and genotype to its *** transplanted 37 genotypes of *** into two common gardens across low and high elevations(2800 vs.3800 m)during *** fitness-related traits were measured,including flowering probability and glucosinolates(GS)*** estimated the environmental or genotypic contributions to the phenotype and identified the main environmental *** results revealed that both environment and genotype-by-environment interactions contributed to the phenotypes of *** heterogeneity was identified as a key factor that explained 24%of the total phenotypic *** particular,genotypes of the northern HDM showed significantly higher plasticity in flowering probability than those of the southern ***,within the southern HDM,GS content indicated local adaptation to herbivory stresses for *** genotypes along *** conclusion,our results suggest that *** may have adapted to the alpine environment through species-level plasticity or regional-level local *** processes were shaped by either complex topography or interactions between genotype and mountain *** study provides empirical evidence on the adaptation of alpine plants.

关键词： alpine plant common garden genotype-by-environment Hengduan mountains local adaptation phenotypic plasticity

A Review on Nanomaterial-based Strategies for Manipulating Tumor Microenvironment to Enhance Chemodynamic Therapy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第2期40卷 202-212页

作者： CAO Mengyu xing Xiner shen Xiaotong OUYANG Jin NA Na Key Laboratory of Radiopharmaceuticals Ministry of EducationCollege of ChemistryBeijing Normal UniversityBeijing100875P.R.China Department of Chemistry College of Arts and SciencesBeijing Normal University at ZhuhaiZhuhai519087P.R.China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430074P.R.China

Cancer is a leading cause of death worldwide,and a series of strategies has been reported for tumor-specific ***,chemodynamic therapy(CDT)has become a research hotspot for antitumor treatment due to its advantages of high specificity,endogenous stimulation,and high ***,the therapeutic effects of CDT are normally limited in the complex tumor microenvironment(TME),such as insufficient acidity,tumor hypoxia,low hydrogen peroxide(H2O2),and high glutathione(GSH).Consequently,different kinds of multifunctional nanomaterials have been designed to manipulate TME conditions,which provided more opportunities to improve the efficiency of *** review focuses on nanomaterial-based strategies for enhancing CDT through manipulating *** CDT enhancements,this review would provide a reference for the future development of efficient CDT nanomaterials.

关键词： Chemodynamic therapy Tumor microenvironment Nanomaterial Manipulating strategy Fenton/Fenton-like reaction

Enhanced Flexoelectricity in Barium Titanate-Cellulose Composite Thin Films

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第4期37卷 521-527页

作者： Wensi xing Hongyu Cao Xin Zhang Xu Liang Jianwei Song shengping shen Chemomechanics and Intelligent Media Laboratory State Key Laboratory for Strength and Vibration of Mechanical StructuresSchool of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049China

Biopolymers,the potential flexoelectric materials,are environment-friendly,degradable,lightweight,cost-effective,and possess remarkable processing properties catering to the requirements of advanced ***,the flexoelectric coefficient of biopolymers is normally much weaker than that of ceramic materials,limiting their potential applications for designing high-performance green electromechanical coupling *** improve the flexoelectric response in biopolymers,we composited barium titanate(BTO)with 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibrils(TOCNF)to enhance the flexoelectric response of *** to the high permittivity and flexoelectric effect of BTO,the relative dielectric constant and flexoelectric coefficient of 33.3 wt%BTO-TOCNF films reached 30.94@1 kHz and 50.05±1.88 nC/m@1 Hz,which were almost 172 times and 27 times higher than those of TOCNF,*** composite thin film contains high dielectric constant and flexoelectric coefficient,as well as excellent *** study provided a straightforward and efficient method for improving the flexoelectric effect of biopolymers,and demonstrated its great potential applications in flexoelectric-based devices.

关键词： Flexoelectricity Cellulose BaTiO_(3) Composite Thin films