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Synthesis of crosslinked polystyrene particles by seeded batch polymerization with monomer absorption

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 153-159页

作者： Ki-Chang LEE Han-ah WI Department of Polymer Science and Engineering Engineering Research Institute Gyeongsang National University

A highly crosslinked, monodispersed polystyrene（PS） particle was prepared by a seeded batch dispersion polymerization with a monomer absorption method. Prior to polymerization, 1,9 lam monodispersed PS seed particles were treated under an optimum condition of monomer absorption. The effects of divinylbenzebe（DVB） concentration and polymerization temperature were examined for styrene（in PS seed）/styrene（in the second stage） mass ratio of 1：1 in the medium range of EtOH/water mass ratio of 100/0-80/20 and 2.3 μm uniform crosslinked PS particles containing 15%-20% （mass fraction） DVB were prepared at 60-70 ℃. The results show that monomer absorption before the second stage of polymerization is more effective to prepare highly crosslinked monodispersed PS particles.

关键词： crosslinked polystyrene particle seeded batch dispersion polymerization monomer absorption divinylbenzene (DVB)

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Hemoglobin induces colon cancer cell proliferation by release of reactive oxygen species

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World Journal of Gastroenterology 2006年第35期12卷 5644-5650页

作者： Ryung-ah Lee Hyun-ah Kim Bo-Young Kang Kwang-Ho Kim Ewha Medical Institute Department of Surgery College of Medicine Ewha Womans University Seoul Korea Department of Surgery College of Medicine Ewha Womans University Seoul Korea Ewha Medical Institute Ewha Womans University Seoul Korea

AIM: To study whether hemoglobin could amplify colon cancer cell proliferation via reactive oxygen species (ROS) production. METHODS: Colon cancer cell line HT-29 was grown in the conventional method using RPMI1640 media. The viability of the cells was measured using the colorimetric MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazo- lium bromide] assay after adding hemoglobin. We de- termined reactive oxygen species levels to be indicators of oxidative stress in HT 29 cell lines with and without hemoglobin and/or 5-fluorouracil (5-FU), 5’-deoxy-5-flu- orouridine (5-DFUR) using fluorometric dichlorofluorescin diacetate (DCFH-DA) assay. RESULTS: Cellular proliferation was increased with he- moglobin in a concentration-dependent manner. A signif- icant increment on ROS levels was found in HT 29 cells following hemoglobin incubation. The cytotoxic effects of 5-FU and 5-DFUR were significantly blunted by admin- istration of hemoglobin. There was a slight increase of peroxiredoxin 1, superoxide dismutase 1 concentration according to different hemoglobin concentrations. CONCLUSION: Hemoglobin has a cellular proliferative effect on HT-29 colon cancer cell line by production of ROS. Also, hemoglobin abates cytotoxic effects of che- motherapeutic agents such as 5-FU and 5-DFUR.

关键词： Colon cancer Hemoglobin Reactive oxygen species

Development of hyaluronic acid-based edible film for alleviating dry mouth

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Food Science and Human Wellness 2023年第2期12卷 371-377页

作者： Dong-Keon Kweon Jung-ah Han Jinwoo Bio Co. Ltd.Yongin 17111Korea Department of Food and Nutrition Sangmyung UniversitySeoul 03016Korea

For alleviating dry mouth symptoms,edible films based on hyaluronic acid(HA)with 3 different m(800,1200 and 2300 kDa)were prepared(800 F,1200 F and 2300 F,respectively),and the properties as well as effectiveness were *** concentration of each HA dispersion for film forming was set as 3.0%,1.5%or 1.0%,for the m800,1200 and 2300 kDa,respectively,based on the *** 800 F showed the highest thickness,tensile strength,and water vapor transparency,whereas obtained the lowest transparency and elongation at break among *** of the HA films showed safety against microorganism during 28 storage day at 40℃with 60%*** optimum site for film attachment in mouth was the palate,and800 F was the most effective for stimulating saliva secretion,eliciting a 38%increase compared to control(without film),tested by the elderly over 65 years *** the sensory test,800 F was also the most *** on above results,the edible films effectively stimulating saliva secretion could be produced with HA,and the physical,sensory characteristics as well as disintegration times of the film could be controlled by mand the dissolution concentration of HA.

关键词： Edible film Hyaluronic acid Saliva stimulating Tensile strength Thickness

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Digital exchange attributes and the risk of closure

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Blockchain(Research and Applications) 2023年第2期4卷 136-145页

作者： Seung ah Lee George Milunovich Department of Actuarial Studies and Business Analytics Macquarie UniversitySydneyNSW2109Australia

Presently,there are over 500 cryptocurrency exchanges worldwide and more than 19,700 different *** the fact that cryptocurrency trading is possible via private peer-to-peer transactions,more than 90%of trading occurs on organised exchanges,which provide convenience and ***,centralised cryptocurrency exchanges are regarded as high-value targets by criminals and are often victims of *** this paper,we investigate the risk of cryptocurrency exchange closures and develop predictive models to forecast which markets will close down and which ones will remain active using publicly available *** models perform well and reach a high level of classification *** trading volume,the availability of public information on exchange staff,exchange lifetime,and several cybersecurity features are identified as key attributes in predicting exchange ***,our models do not account for all sources of risk,e.g.,potential fraud and mismanagement of client funds committed by the exchanges themselves,and market participants are encouraged to carefully consider where and how they store their digital assets.

关键词： Cryptocurrency markets Digital exchange Closure Classification Predictive models

Natural dietary anti-cancer chemopreventive compounds:redox-mediated differential signaling mechanisms in cytoprotection of normal cells versus cytotoxicity in tumor cells

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Acta Pharmacologica Sinica 2007年第4期28卷 459-472页

作者： Sujit NAIR ah-Ng Tony KONG Graduate Program in Pharmaceutical Sciences Department of Pharmaceutics Ernest Mario School of PharmacyRutgersThe StateUniversity of New JerseyPiscatawayNew Jersey 08854USA

Many dietary phytochemicals exhibit health-beneficial effects including preven-tion of diseases such as cancer,as well as neurological,cardiovascular,inflam-matory,and metabolic ***,herbivorous and omnivorousanimals have been ingesting *** interaction between"animal-plant"ecosystems has resulted in an elaborate system of detoxification and defensemechanisms evolved by animals including *** cells,includinghuman cells,respond to these dietary phytochemicals by"non-classical receptorsensing"mechanisms of electrophilic chemical-stress typified by"thiol-modu-lated"cellular signaling events primarily leading to the gene expression of phar-macologically beneficial effects,but sometimes unwanted cytotoxicity *** has been studying two groups of dietary phytochemical cancer-chemopreventive compounds (isothiocyanates and polyphenols),which areeffective in chemical-induced,as well as genetically-induced,animal carcinogen-esis *** compounds typically generate"cellular stress"and modulategene expression of phase Ⅱ detoxifying/antioxidant ***,reac-tive oxygen species,and reactive nitrogen species are known to act as secondmessengers in the modulation of many cellular signaling pathways leading togene expression changes and pharmacological ***-sensitive tran-scription factors such as nuclear factor-E2-related factor 2 (Nrf2),AP-1,NF-κB,tocite a few examples,sense and transduce changes in the cellular redox status andmodulate gene expression responses to oxidative and electrophilic stresses,pre-sumably via sulfhydryl modification of critical cysteine residues found on theseproteins and/or other upstream redox-sensitive molecular *** the currentreview,we will explore dietary cancer chemopreventive phytochemicals,discussthe link between oxidative/electrophilic stresses and the redox circuitry,and con-sider different redox-sensitive transcription *** will also discuss thekelch-l

关键词： redox Nrf2 Keapl NES NLS gene expression profiles

Studies on the flow and distribution of leukocytes in mesentery microcirculation of rats

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World Journal of Gastroenterology 1999年第3期5卷 231-234页

作者： Jiang Y Liu ah Zhao KS Mil Med Univ 1st Chinese PLA Lab Shock & Microcirculat Guangzhou 510515 Peoples R China

AIM To study the effect of leukocyteendothelium interaction (LEI) on the flow anddistribution of leukocytes in microcirculationunder physiological *** A microcirculation image multipleparameter computer analysis system (MIMPCAS)was used to study the flow and distribution ofleukocytes in mesentery microcirculation of ratsIn *** The difference of visible leukocyteflux (VLF) was as high as 131 times in thearterioles and venules with similar diameter andblood velocity. The visible leukocytes rolledalong the blood vessel wall as a" jerky"movement. The frequency distribution of thevisible leukocyte velocity (VLV) showed a "twopeak" Curve. The low peak value was at 10 pm/ s-- 15 pm/ s while the high peak fell between25 pm/ s-- 30 pm/ s. With the increase of diameterof venules, VLF increased while the VLVremained at the same level. With the increase ofRBC velocity, VLV trends to elevate and VLF tofal I *** The results herein might providea basic theory for the study on the mechanism ofLEI under physiological condition and novelmethods for the prevention and treatment of highLEI in many pathological

关键词： Studies on the flow and distribution of leukocytes in mesentery microcirculation of rats flow

The anti-tubercular activity of Melia azedarach L. and Lobelia chinensis Lour. and their potential as effective anti-Mycobacterium tuberculosis candidate agents

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Asian Pacific Journal of Tropical Biomedicine 2016年第10期6卷 830-835页

作者： Won Hyung Choi In ah Lee Department of Biomedical Science School of Medicine Kyung Hee University Department of Medical Zoology School of Medicine Kyung Hee University Department of Chemistry College of Natural Science Kunsan National University

Objective: To evaluate the anti-mycobacterial activity of Melia azedarach L.(M. azedarach) and Lobelia chinensis Lour.(L. chinensis) extracts against the growth of Mycobacterium tuberculosis(M. tuberculosis).Methods: The anti-M. tuberculosis activity of M. azedarach and L. chinensis extracts were evaluated using different indicator methods such as resazurin microtiter assay(REMA) and mycobacteria growth indicator tube(MGIT) 960 system assay. The M. tuberculosis was incubated with various concentrations(50–800 mg/m L) of the extracts for 5 days in the REMA, and for 4 weeks in MGIT 960 system ***: M. azedarach and L. chinensis extracts showed their anti-M. tuberculosis activity by strongly inhibiting the growth of M. tuberculosis in a concentration-dependent manner in the REMA and the MGIT 960 system assay. Particularly, the methanol extract of M. azedarach and n-hexane extract of L. chinensis consistently exhibited their effects by effectively inhibiting the growth of M. tuberculosis in MGIT 960 system for 4 weeks with a single-treatment, indicating higher anti-M. tuberculosis activity than other extracts,and their minimum inhibitory concentrations were measured as 400 mg/m L and 800 mg/m L, ***: These results demonstrate that M. azedarach and L. chinensis extracts not only have unique anti-M. tuberculosis activity, but also induce the selective antiM. tuberculosis effects by consistently inhibiting or blocking the growth of M. tuberculosis through a new pharmacological action. Therefore, this study suggests the potential of them as effective candidate agents of next-generation for developing a new anti-tuberculosis drug, as well as the advantage for utilizing traditional medicinal plants as one of effective strategies against tuberculosis.

关键词： Lobelia chinensis Lour. Melia azedarach L. MGIT 960 system Drug susceptibility Tuberculosis

Thermal Efficiency for Each Zone of a Solar Pond

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Chinese Physics Letters 2011年第10期28卷 281-283页

作者： BEZİR CİCEK Nalan ŞahİNŞENCAN Arzu Department of Physics Faculty of ScienceSuleyman Demirel UniversityTurkey Department of Mechanical Education Technical Education FacultySüleyman Demirel UniversityTurkey

A salt gradient solar pond with a surface area of 3.5×3.5 m^(2) and a depth of 2 m is *** collapsible covers are used to reduce thermal energy loss from the surface of the solar pond during the night and to increase the thermal efficiency of the pond solar energy harvesting during *** covers can be rotated between 0 and 180°by a controlled electric motor and has insulation and reflection *** thermal efficiency for each solar pond zone is investigated theoretically and experimentally.

关键词： properties insulation harvesting

Pharmacometrics of nutraceutical sulforaphane and its implications in prostate cancer prevention

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Journal of Chinese Pharmaceutical Sciences 2016年第1期25卷 12-22页

作者： Sujit Nair ah-Ng Tony Kong Amrita Cancer Discovery Biology Laboratory Amrita Vishwa Vidyapeetham University Center for Cancer Chemoprevention Research and Department of Pharmaceutics Rutgers The State University of New Jersey

Sulforaphane(SFN), found in broccoli and other cruciferous vegetables, has a beneficial effect in chemoprevention of prostate cancer, whose incidence and associated mortality have gradually increased worldwide. There is great enthusiasm for bench-to-bedside development of SFN as a potent chemopreventive agent, possibly alone or as an adjunct to existing chemotherapy regimens, in the oncology care setting to reduce toxicity of chemotherapeutics and potentially enhance their cancer cell-kill efficacy. In this review, we appreciate existing knowledge on SFN using a pharmacometrics approach, which is fast becoming a gold standard in discovery research and validation of New Chemical Entities and New Biological Entities in pharmaceutical industry. We discuss the epistemology of SFN target engagement and quantitative systems pharmacology with due emphasis on mechanistic pharmacology, pharmacodynamics, pharmacogenomics and metabolism of SFN. In addition, we explore the quantitative freeway to SFN translational medicine by assessing the preclinical and clinical PK/metabolism aspects of SFN that form the cornerstone of SFN pharmacometric evaluation, as well as the promise of SFN in prostate cancer. Taken together, we share perspectives on the exciting developments in translational cancer chemoprevention, with emphasis on the pharmacometric aspects, of the nutraceutical SFN which is currently in clinical trials, and suggest that the pharmacometric approach holds great promise in the SFN translational pharmacology paradigm for prostate cancer.

关键词： Pharmacometrics Pharmacokinetics Quantitative systems pharmacology Target engagement Metabolism Pharmacogenomics Chemoprevention Sulforaphane Isothiocyanate Prostate cancer

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