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The Roles of Barotropic Instability and the Beta Effect in the Eyewall Evolution of Tropical Cyclones 被引量:1
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作者 Jie JIANG Yuqing WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第11期1800-1815,共16页
Diabatic heating by convection in the eyewall often produces an annular region of high potential vorticity(PV)around the relatively low PV eye in a strong tropical cyclone(TC).Such a PV ring is barotropically unstable... Diabatic heating by convection in the eyewall often produces an annular region of high potential vorticity(PV)around the relatively low PV eye in a strong tropical cyclone(TC).Such a PV ring is barotropically unstable and can encourage the exponential growth of PV waves.In this study,such instability and the subsequent nonlinear evolution of three TC-like vortices having PV rings with different degrees of hollowness on an f-plane are first examined using an unforced,inviscid shallow-water-equation model.Results show that the simulated eyewalls evolve similarly to those in the nondivergent barotropic model.It is also found that the polygonal eyewall structure can be decomposed into vortex Rossby waves(VRWs)of different wavenumbers with different amplitudes,allowing for wave-wave interactions to produce complicated behaviors of mesovortices in the TC eyewall.The same set of PV rings has been examined on a beta-plane.Although the beta effect has been rendered unimportant to the eyewall evolution due to the relatively small scale of the inner-core circulation,this study shows that the beta effect may erode the coherent structure of mesovortices in the eyewall of an initially hollow PV-ring vortex.Mesovortices modeled on the beta-plane with a greater beta parameter tend to experience an earlier breakdown and enhanced radial gradients of the basic-state(azimuthally mean)angular velocity,followed by wave-wave,wave-flow interactions,leading to earlier merger and axisymmetrization processes.This result implies that the beta effect could be one of the forcings that shorten the lifetime of quasi-steady mesovortices in the eyewall of real TCs. 展开更多
关键词 tropical cyclones vortex rossby waves barotropic instability beta effect
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Public Effective Dose Assessment Using Gross Alpha and Beta Radioactivity Levels of Tap Drinking Water in the District of Abidjan, Cote d’Ivoire
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作者 Ponaho Claude Kezo Issa Konate Tekpo Paul Dali 《Journal of Environmental Protection》 CAS 2023年第3期127-138,共12页
In order to assess public effective dose due to gross alpha and beta in water, 43 tap water samples were collected from different areas in the District of Abidjan. Using the low background Gas-less Automatic Alpha/Bet... In order to assess public effective dose due to gross alpha and beta in water, 43 tap water samples were collected from different areas in the District of Abidjan. Using the low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) for analysis, the gross alpha and beta concentrations found varied from 0.001 ± 0.002 to 0.063 ± 0.050 Bq/l with an average of 0.013 ± 0.012 Bq/l and from 0.067 ± 0.080 to 0.320 ± 0.120 Bq/l with an average of 0.174 ± 0.076 Bq/l, respectively in samples. The public effective dose assessment showed values of dose to ingestion of alpha and beta emitter radionuclides lower than the recommended value of dose for drinking water 0.1 mSv/y, except in 30% of the samples. These results show the need for additional studies to be conducted in order to clarify the hazardousness of these water samples. However, this study still remains important because it has provided necessary data for future tap water quality monitoring studies in the District of Abidjan. 展开更多
关键词 Gross Alpha and beta Concentration Tap Water effective Dose District of Abidjan
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Gross Alpha and Beta Activities and Related Lifetime Risks Assessment Due to Ingestion of Drinking Water from Different Sources in the District of Abidjan, Cote d’Ivoire
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作者 Ponaho Claude Kezo Issa Konate Dabo Salif Ignace Agba 《World Journal of Nuclear Science and Technology》 CAS 2024年第1期86-96,共11页
Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the ... Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the objective of this study was to assess the risk of cancer due to the ingestion of alpha and beta emitting radionuclides in the different types of water consumed in the region. A total of 63 water samples with 43 tap water samples, 5 bottled mineral water and 15 sachet water samples was collected and taken to GAEC laboratory for analysis. The low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) was used to determine alpha and beta activity concentrations. Activity concentrations of both gross alpha and gross beta obtained in water sample were respectively lower than the WHO recommended limits of 0.1 Bq/l and 1 Bq/l. Also, the annual effective dose and total equivalent effective dose found in mineral bottled water samples were higher than in other types of water. The assessment of radiological lifetime risk has shown values of cancer risk due to ingestion alpha and beta emitters lower than recommended limit. These results indicate that there is no health hazard associated to consumption of water in the District of Abidjan. 展开更多
关键词 Gross Alpha and beta Activities Drinking Water effective Dose Radiological Lifetime Risks
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The Effect of Adjuvants on Penetration of beta-cypermethrin Through the Epidermis of Cabbage Leaf 被引量:3
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作者 WANG Yi, ZHANG Li-ta, ZHENG Fei-neng, CHEN Fu-liang and LIANG Wen-ping( Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100094 Center for Molecular Science , Institute of Chemistry , The Chinese Academy of Sciences , Beijing 100101 ) 《Agricultural Sciences in China》 CAS CSCD 2002年第3期313-318,共6页
The effects of three types of adjuvant (mineral oil, higher aliphatic acid and nonionic surfactant) on the penetration of beta-cypermethrin through the cabbage leaf surface were studied. The results showed that the pe... The effects of three types of adjuvant (mineral oil, higher aliphatic acid and nonionic surfactant) on the penetration of beta-cypermethrin through the cabbage leaf surface were studied. The results showed that the penetration was positively correlated with both the concentration of adjuvant and the time after application, in a given range of treatment. A synergistic effect of two types of adjuvant on the penetration was found. Some physical properties of emulsions were determined. The change of the structures of the cabbage leaf surface by these adjuvants was observed from photomicrographs. The mechanism concerned with the effect of these adjuvants on the penetration of beta- cypermethrin through the cabbage leaf surface was tentatively discussed. 展开更多
关键词 ADJUVANT Nonionic surfactant PENETRATION beta-CYPERMETHRIN Synergistic effect
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Effects of natural-cerebrolysin-containing serum on neurotoxicity and synaptogenesis in amyloid-beta 1-40-induced Alzheimer's disease in vitro models 被引量:1
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作者 Yinghong Li Zhengzhi Wu +3 位作者 Andrew C. J. HuangO Ming Li XiaoLi Zhang Jiguo Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第2期85-91,共7页
BACKGROUND: Neuronal loss, synapse mutilation, and increasing malnourished axons are pathologically related to Alzheimer's disease. Microtubule-associated protein 2 (MAP2) is of importance for neuronal, axonal, an... BACKGROUND: Neuronal loss, synapse mutilation, and increasing malnourished axons are pathologically related to Alzheimer's disease. Microtubule-associated protein 2 (MAP2) is of importance for neuronal, axonal, and dendritic generation, extension, and stabilization, as well as for the regulation of synaptic plasticity. OBJECTIVE: To investigate the antagonistic effects of natural-cerebrolysin-containing serum on beta amyloid protein 1-40 (Aβ1-40)-induced neurotoxicity from the standpoints of cell proliferation, synaptogenesis, and cytoskeleton formation (MAP2 expression). DESIGN, TIME AND SETTING: A paralleled, controlled, neural cell, and molecular biology experiment was performed at the Institute of Integrated Chinese and Western Medicine, Shenzhen Hospital, Southern Medical University between February 2006 and April 2008. MATERIALS: PC12 cells, derived from the rat central nervous system, were purchased from Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China. A β1-40 was provided by Sigma, USA. Natural-cerebrolysin was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. The natural-cerebrolysin was predominantly composed of Renshen (Radix Ginseng), Tianma (Rhizoma Gastrodiae), and Yixingye (Ginkgo Leaf) in a proportion of 1:2:2. Following conventional water extraction technology, an extract (1:20) was prepared. Each gram of extract equaled 20 grams of crude drug. In a total of 12 adult male New Zealand rabbits, six underwent intragastric administration of natural-cerebrolysin extract for 1 month to prepare natural-cerebrolysin-containing serum, and the remaining six rabbits received intragastric administration of physiological saline to prepare normal blank serum. METHODS: An AIzheimer's disease in vitro model was induced in PC12 cells using Aβ1-40. The cells were incubated with varying doses of natural-cerebrolysin-containing serum (2.5%, 5%, and 10%). Normal blank serum-treated PC12 cells served as a blank control group. MAIN OUTCOME MEASURES: Through the use of inverted phase contrast microscope, cell morphology and neurite growth were observed, neurite length was measured, and the percentage of neurite-positive cells was calculated. Cell proliferation rate was determined by MTT assay, and MAP 2 expression was detected by fluorescent immunocytochemistry. RESULTS: Following Aβ1-40 treatments, some PC12 cells were apoptotic/dying, and only a few short neurites were observed. Following interventions with natural-cerebrolysin-containing serum, the PC12 cells proliferated, there was an increased number of neurites, and neurite length was enhanced. After middle- and high-dose natural-cerebrolysin treatments, the percentage of neurite-positive cells, as well as the average length of neurites, was significantly greater than the normal blank serum-treated PC12 cells (P 〈 0.05 or P 〈 0.01). Compared with the blank control group, MAP2 expression in the Aβ1-40-treated PC12 cells was significantly inhibited, and the cell proliferation rate was significantly decreased (P 〈 0.01). Following incubations with natural-cerebrolysin-containing serum, MAP2 expression and cell proliferation rate in the PC12 cells were significantly increased in a dose-dependent manner, compared with treatments with blank control serum (P 〈 0.05 or P 〈 0.01 ). CONCLUSION: Natural-cerebrolysin exhibited antagonistic effects on neurotoxicity in Aβ1-40 induced Alzheimer's disease in vitro models. These effects were likely related to cell proliferation and the upregulation of intracellular MAP2 expression. 展开更多
关键词 natural-cerebrolysin Alzheimer's disease in vitro model NEUROTOXICITY neuroprotective effect amyloid beta protein 1-40
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Effects of natural cerebrolysin on protective proteins and pro-apoptotic molecules in mesenchymal stem cells following beta-amyloid peptide1-40-induced endoplasmic reticulum stress 被引量:1
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作者 Yinghong Li Zhengzhi Wu +4 位作者 Ming Li Xiaoli Zhang Min Yang Manyin Chen Andrew C. J.Huang O 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第12期986-993,共8页
BACKGROUND: Studies have demonstrated that β-amyloid peptide (Aβ), a characteristic pathological product of Alzheimer's disease (AD), results in neuronal endoplasmic reticulum stress (ERS). However, the mech... BACKGROUND: Studies have demonstrated that β-amyloid peptide (Aβ), a characteristic pathological product of Alzheimer's disease (AD), results in neuronal endoplasmic reticulum stress (ERS). However, the mechanisms of traditional Chinese medicine against ERS in AD are poorly understood. OBJECTIVE: To measure expression levels of protective proteins (GRP78 and GRP94) of ER molecular partners and pro-apoptotic Caspase-12 ER membrane expression following application of traditional Chinese medicine natural cerebrolysin (NC) to treat Aβ1-40-induced ERS. DESIGN, TIME AND SETTING: A parallel-controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital of Southern Medical University between September 2006 and November 2008. MATERIALS: Sprague Dawley male rats, 6-8 weeks old, were used to harvest tibial and femoral bone marrow. Isolation and purification of mesenchymal stem cells (MSCs) were established from the whole bone marrow by removing non-adherent cells in primary and passage cultures. Aβ1-40 was provided by Sigma, USA. NC was provided by Shenzhen Institute of Integrated Chinese and Western Medicine, China. NC was predominantly composed of Renshen (Radix Ginseng), Tianma (Rhizoma Gastrodiae), and Yinxingye (Ginkgo Leaf) in a proportion of 1 : 2: 2. Following conventional water extraction technology, an extract (1 : 20) was prepared. Six adult, male, New Zealand rabbits underwent intragastric administration of NC extract (0.976 g/kg per day) for 1 month to prepare NC-positive serum, and the remaining 6 rabbits received intragastric administration of physiological saline to prepare normal blank serum. METHODS: A total of 500 nmol/L Aβ1-40 was used to establish ERS models of primary cultured MSCs. AD cell models were incubated with different doses of NC-positive serum (2.5%, 5%, and 10%). MSCs treated with normal blank serum served as normal blank controls. MAIN OUTCOME MEASURES: Reverse transcription-polymerase chain reaction and fluorescent immunocytochemistry were respectively used to measure mRNA and protein expression levels of GRP78, GRP94, and Caspase-12 in MSCs. RESULTS: Following Aβ1-40 exposure, mRNA and protein expression levels of GRP78 and GRP94, as well as Caspase-12, significantly increased (P 〈 0.05), suggesting successful establishment of ERS models. Following NC-positive serum application, mRNA and protein expression levels of GRP78 and GRP94 in MSCs significantly increased (P 〈 0.05 or P 〈 0.01). However, mRNA and protein expression levels of Caspase-12 significantly decreased (P 〈 0.05, or P 〈 0.01) compared with the ERS model group. These effects were dose-dependent. CONCLUSION: NC downregulated Caspase-12 expression and upregulated GRP78 and GRP94 expression in MSCs in a dose-dependent manner under the state of Aβ1-40-induced ERS. 展开更多
关键词 endoplasmic reticulum stress amyloid beta protein 1-40 Alzheimer's Disease natural cerebrolysin protective effect mesenchymal stem cells
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作物发育温度非线性效应Beta模型的特征分析 被引量:12
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作者 吕贞龙 徐寿军 庄恒扬 《生态学报》 CAS CSCD 北大核心 2008年第8期3737-3743,共7页
Beta模型在反映温度对作物发育非线性效应方面被广泛采用。为使该函数满足在设定的最适温度下函数值取值最大的条件,得到Beta模型的特殊形式。分析认为,该模型满足温度对作物发育影响的三基点规律、较好地反映发育速率对温度变化的响应... Beta模型在反映温度对作物发育非线性效应方面被广泛采用。为使该函数满足在设定的最适温度下函数值取值最大的条件,得到Beta模型的特殊形式。分析认为,该模型满足温度对作物发育影响的三基点规律、较好地反映发育速率对温度变化的响应特征、温度三基点在模型中应比较明确的3个规范性要求,具有较强的变化特征表达能力,可以近似表达二次函数、高斯函数等函数的变化。分析了Beta模型与积温法计算结果的关系。通过对Beta模型一阶和二阶导数的分析,明确了其变化特征,指出已有研究对参数P生物学意义解释的不妥之处,提出作物发育速度对温度的非线性响应是感温性的本质特征的观点,并从新的视角肯定了参数P在一定程度上可以作为作物感温性强弱的度量。 展开更多
关键词 作物发育 温度效应 beta模型 感温性
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转甲状腺素蛋白抑制β淀粉样蛋白聚集的分子机制研究
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作者 周双艳 黄垚心 +2 位作者 李鑫 白佳慧 袁帅 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2024年第3期633-646,共14页
目的转甲状腺素蛋白(transthyretin,TTR)对阿尔茨海默病(Alzheimer’s disease,AD)具有神经保护作用,这种保护作用表现在TTR能抑制β淀粉样蛋白(amyloid beta protein,Aβ)的病理性聚集。本工作将从分子层面上探究TTR与Aβ的作用机制,揭... 目的转甲状腺素蛋白(transthyretin,TTR)对阿尔茨海默病(Alzheimer’s disease,AD)具有神经保护作用,这种保护作用表现在TTR能抑制β淀粉样蛋白(amyloid beta protein,Aβ)的病理性聚集。本工作将从分子层面上探究TTR与Aβ的作用机制,揭示TTR对AD的神经保护作用。方法蛋白质-蛋白质对接用于探究不同结构形式的TTR与Aβ的作用模式,并运用分子动力学模拟方法来探究二者相互作用的动态过程。结果TTR四聚体及单体均能与Aβ单体作用,TTR四聚体的甲状腺素结合通道是Aβ单体的主要结合部位。此外,TTR四聚体的EF螺旋、EF loop同样能够结合Aβ单体。当TTR四聚体解离后,TTR单体的内部片层疏水部位暴露,该部位对Aβ单体具有较强的亲和力。TTR与Aβ聚集体作用,由于TTR单体与Aβ聚集体均为富含β折叠的结构,使得二者能够共聚集形成聚合度更高的聚集体,从而降低Aβ聚集体的细胞毒性。结论TTR四聚体和单体通过“扣押”Aβ单体来抑制Aβ的聚集,TTR单体与Aβ聚集体形成高聚合度复合物来降低Aβ聚集体的细胞毒性。本工作为基于TTR神经保护作用的抗AD药物设计和发现提供了重要的理论依据。 展开更多
关键词 阿尔茨海默病 转甲状腺素蛋白 神经保护作用 Β淀粉样蛋白 分子动力学模拟
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Comparison of time-related electrical properties of PN junctions and Schottky diodes for Zn O-based betavoltaic batteries 被引量:2
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作者 Xiao-Yi Li Jing-Bin Lu +4 位作者 Ren-Zhou Zheng Yu Wang Xu Xu Yu-Min Liu Rui He 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第2期55-66,共12页
Schottky diodes and PN junctions were utilized as energy converting structures in ZnO-based betavoltaic batteries,in which 0.101121 Ci 63Ni was selected as the beta source.The time-related electrical properties were o... Schottky diodes and PN junctions were utilized as energy converting structures in ZnO-based betavoltaic batteries,in which 0.101121 Ci 63Ni was selected as the beta source.The time-related electrical properties were obtained using Monte Carlo simulations.For the n-type ZnO,the Pt/ZnO Schottky diode had the highest energy conversion efficiency,and the Ni/ZnO Schottky diode had the largest Isc.The overall electrical performance of PN junctions is better than that of Schottky diodes.The lifetimes of Pt/ZnO and Ni/ZnO are longer than for other Schottky devices,coming close to those of PN junctions.Considering that Schottky diodes are easier to fabricate and independent of p-type semiconductors,Pt/ZnO and Ni/ZnO diodes offer alternatives to PN-junction-based betavoltaic batteries. 展开更多
关键词 beta voltaic effect Zinc oxide Time-related properties PN junction Schottky diode Monte Carlo simulation
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Exploratory study of betavoltaic battery using ZnO as the energy converting material 被引量:2
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作者 Xiao-Yi Li Jing-Bin Lu +3 位作者 Yu-Min Liu Xu Xu Rui He Ren-Zhou Zheng 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第4期62-69,共8页
Third-generation-semiconductor zinc oxide is utilized as an energy converting material in a betavoltaic battery, where 0.06 Ci^(63) Ni and 8 Ci^(147) Pm are used as the beta sources. Based on a Monte Carlo simulation,... Third-generation-semiconductor zinc oxide is utilized as an energy converting material in a betavoltaic battery, where 0.06 Ci^(63) Ni and 8 Ci^(147) Pm are used as the beta sources. Based on a Monte Carlo simulation, the full scales of the devices are derived as 17 and 118 lm,respectively, for both sources. The influences of semiconductor doping concentrations on the electrical properties of the devices are analyzed. For a typical doping concentration N_A= 10^(17) cm^(-3), N_D= 10^(16) cm^(-3), the conversion efficiencies are 7.177% and 1.658%, respectively, using63 Ni and147 Pm sources. The calculation results of energy deposition in materials for the two sources show that the doping concentrations drop to 1 × 10^(13)–5×10^(14) cm^(-3) and 1 × 10^(12)–5×10^(13), and accordingly, the energy conversion efficiencies rise to 14.212% and 18.359%, respectively. 展开更多
关键词 RADIOISOTOPE beta voltaic effect Zinc oxide Nuclear BATTERY MONTE Carlo simulation
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Telencephalin protects Paju cells from beta-amyloid protein-induced apoptosis 被引量:1
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作者 Heping Yang Dapeng Wu +3 位作者 Xiaojie Zhang Xiang Wang Yi Peng Zhiping Hu 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第29期2251-2255,共5页
Previous studies have confirmed that telencephalin (TLN) is a neural glycoprotein that protects axonal disruption induced by the beta-amyloid protein (Aβ42/35) in the neural crest-derived tumor cell line Paju. Th... Previous studies have confirmed that telencephalin (TLN) is a neural glycoprotein that protects axonal disruption induced by the beta-amyloid protein (Aβ42/35) in the neural crest-derived tumor cell line Paju. The present study investigated the effects of TLN on neuronal degeneration induced by Aβ42 in the differentiated Paju cell line. Results demonstrated that after cultivating cells in Aβ42 medium, the survival rate of Paju-TLN cells was significantly higher than that of Paju-neo cells, and that apoptotic rate was noticeably reduced. These results indicate that TLN reduces Paju cell apoptosis induced by Aβ42. 展开更多
关键词 telencephalin/intercellular adhesion molecule-5 beta-amyloid protein neuroprotective effect APOPTOSIS Alzheimer's disease neural regeneration
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Etherification of HMF to biodiesel additives: The role of NH4+ confinement in Beta zeolites 被引量:1
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作者 Paola Lanzafame Georgia Papanikolaou +2 位作者 Katia Barbera Gabriele Centi Siglinda Perathoner 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第9期114-121,共8页
The role of NH4^+ ion confinement in the catalytic etherification of HMF(5-hydroxymethylfurfural) with ethanol to biodiesel additives was evidenced by studying the catalytic behavior of NH4^+-Beta zeolites with SiO2/A... The role of NH4^+ ion confinement in the catalytic etherification of HMF(5-hydroxymethylfurfural) with ethanol to biodiesel additives was evidenced by studying the catalytic behavior of NH4^+-Beta zeolites with SiO2/Al2O3 ratios of 25 and 75.In order to affect the strength and distribution of the acidic sites, as well as the mobility of NH4^+ ions in the zeolites cages, a secondary level of porosity was introduced in the NH4^+-Beta, presenting a different stability versus alkaline treatment, by using a thermal or an ultrasound assisted method.By analyzing the catalytic behavior in these two series of samples with respect to the changes in porosity by nonlocal density functional theory, structure by XRD, amount of acid sites by FT-IR and mobility of NH4^+ cations by measurements of reversible NH4^+ exchange capacity, was evidenced a decrease in catalytic performances both in terms of rate of HMF depletion and productivity to the main products, when confinement of the ammonium ions is lost due to the introduction of mesoporosity.The high capability of ammonium ions release, associated to the mono-dentate configuration,and the minor confinement effect inside the zeolite pore system, due to the more opened pores structure of mesoporous zeolites, hinders both the direct etherification of HMF to EMF [5-(ethoxymethyl)furan-2-carbaldehyde] and the parallel reaction pathway via acetalization, favoring the rapid desorption of the HMFDEA [5-(hydroxymethyl)furfural diethyl acetal] product out of the crystal and the consequent inhibition of the consecutive reactions to EMFDEA [5-(ethoxymethyl)furfural diethyl acetal] and EMF. 展开更多
关键词 AMMONIUM ion beta ZEOLITE HMF ETHERIFICATION CONFINEMENT effect 5-(ethoxymethyl)furan-2-carbaldehyde
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SAPO-11/Beta复合分子筛的合成及其异构化性能研究 被引量:19
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作者 朱数金 刘粟侥 +2 位作者 张怀科 吕恩静 任杰 《催化学报》 SCIE EI CAS CSCD 北大核心 2014年第10期1676-1686,共11页
以Beta分子筛为硅源通过水热合成法合成了SAPO-11/Beta复合分子筛,采用X射线衍射、N2物理吸脱附、扫描电镜、透视电镜-能谱分析、固体核磁及吡啶红外等方法对单分子筛、复合分子筛和机械混合分子筛的物化性质进行了表征.以正十二烷为模... 以Beta分子筛为硅源通过水热合成法合成了SAPO-11/Beta复合分子筛,采用X射线衍射、N2物理吸脱附、扫描电镜、透视电镜-能谱分析、固体核磁及吡啶红外等方法对单分子筛、复合分子筛和机械混合分子筛的物化性质进行了表征.以正十二烷为模型化合物,在固定床反应器上考察了铂负载型分子筛催化剂的异构化性能.结果表明,复合分子筛的物理化学性质明显不同于单分子筛和机械混合分子筛,其呈现核壳结构,SAPO-11和Beta间存在化学作用,使得复合分子筛具有适宜的B酸分布.在正十二烷异构化反应中,复合分子筛催化剂的异构化性能优于单分子筛催化剂和机械混合分子筛催化剂,多支链异构体收率高. 展开更多
关键词 SAPO-11 beta分子筛 复合分子筛 核壳结构 协同作用 临氢异构化反应 多支链异构体
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Effects of combined use of diallyl disulfide and N-acetyl-cysteine on acetaminophen hepatotoxicity in β-naphthoflavone-pretreated mice
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《World Journal of Gastroenterology》 SCIE CAS CSCD 1998年第2期20-24,共5页
EfectsofcombineduseofdiallyldisulfideandNacetylcysteineonacetaminophenhepatotoxicityinβnaphthoflavonepre... EfectsofcombineduseofdiallyldisulfideandNacetylcysteineonacetaminophenhepatotoxicityinβnaphthoflavonepretreatedmiceZHAOCo?.. 展开更多
关键词 DIALLYL DISULFIDE N-ACETYL-CYSTEINE ACETAMINOPHEN beta naphthoflavone liver /drug effectS glutathione 7 alkoxycoumarin O dealkylase
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克林霉素联合碘甘油对慢性牙周炎β-catenin、IL-35和IL-37表达水平的影响研究
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作者 夏章晖 付小红 马威 《临床和实验医学杂志》 2023年第23期2565-2570,共6页
目的探讨克林霉素联合碘甘油对慢性牙周炎β-连环蛋白(β-catenin)、白细胞介素(IL)-35和IL-37表达水平的影响。方法前瞻性选取2021年1月至2022年12月华中科技大学同济医学院附属梨园医院收治的110例慢性牙周炎患者为研究对象,采用随机... 目的探讨克林霉素联合碘甘油对慢性牙周炎β-连环蛋白(β-catenin)、白细胞介素(IL)-35和IL-37表达水平的影响。方法前瞻性选取2021年1月至2022年12月华中科技大学同济医学院附属梨园医院收治的110例慢性牙周炎患者为研究对象,采用随机数字表法分为对照组(n=55)和观察组(n=55),对照组采用碘甘油治疗,观察组采用克林霉素+碘甘油治疗。比较两组的临床疗效、牙周健康[出血指数、探诊出血、牙周袋深度、附着水平]、症状及致病菌好转情况、血清指标[β-catenin、IL-35、IL-37]及不良反应情况。结果治疗7 d后,观察组临床总有效率为98.18%,高于对照组(83.64%),差异有统计学意义(P<0.05)。治疗后,两组的出血指数、探诊出血、牙周袋深度、附着水平、厌氧菌数、β-catenin水平、IL-35水平较治疗前均显著下降,IL-37水平较治疗前上升,且观察组治疗后的出血指数、探诊出血、牙周袋深度、附着水平、厌氧菌数、β-catenin水平、IL-35水平分别为(0.66±0.39)分、(1.31±0.28)个、(2.94±0.31)mm、(3.77±0.41)mm、(4.11±0.41)lg(CFU/mL)、(1.68±0.32)g/L、(122.85±13.14)ng/L,均明显低于对照组[(1.29±0.47)分、(2.11±0.47)个、(4.11±0.12)mm、(4.35±0.53)mm、(5.05±0.63)lg(CFU/mL)、(2.27±0.61)g/L、(161.02±15.64)ng/L],IL-37水平为(131.25±18.01)ng/L,高于对照组[(124.21±17.92)ng/L],差异均有统计学意义(P<0.05)。观察组治疗后所需牙齿松动、咀嚼疼痛、牙龈水肿、口腔异味好转时间分别为(9.78±1.01)、(9.34±0.97)、(10.31±1.25)、(8.49±0.95)d,均短于对照组[(12.48±2.13)、(11.62±1.89)、(13.39±2.26)、(10.84±1.24)d],差异均有统计学意义(P<0.05)。治疗7 d内,观察组与对照组不良反应总发生率比较,差异无统计学意义(P>0.05)。结论在慢性牙周炎的临床治疗中,采用克林霉素联合碘甘油治疗方式,能提升临床治疗效果,促进牙龈肿痛、出血等症状的恢复,抑制杀灭厌氧菌,减轻炎症反应,促进口腔健康的恢复,且有一定用药安全性,值得推广应用。 展开更多
关键词 慢性牙周炎 克林霉素 碘甘油 Β-连环蛋白 白细胞介素 临床疗效
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HA与β-TCP植骨效果及上颌窦提升种植修复临床效果观察
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作者 张艳波 王雪峰 +1 位作者 韩尚志 霍峰 《生命科学仪器》 2023年第5期152-154,共3页
目的分析羟基磷灰石(HA)与β-磷酸三钙(β-TCP)植骨材料的成骨效果及上颌窦提升种植修复功能负载后的临床效果。方法选取2019年3月至2022年3月在承德医学院附属医院口腔科行上颌窦提升植骨同期种植体植入术的患者20例为研究对象,均植入H... 目的分析羟基磷灰石(HA)与β-磷酸三钙(β-TCP)植骨材料的成骨效果及上颌窦提升种植修复功能负载后的临床效果。方法选取2019年3月至2022年3月在承德医学院附属医院口腔科行上颌窦提升植骨同期种植体植入术的患者20例为研究对象,均植入HA与β-TCP骨材料,观察患者术后种植体存留率及相关并发症发生情况,观察术后1、6个月种植体周围骨量。结果20例患者(23枚种植体),种植体植入6个月后影像学检查显示种植体与牙槽骨之间骨结合良好,随访复查种植体存留率100%;HA+β-TCP患者上颌窦底提升植骨术后6个月颊舍、近远中向上颌窦黏膜底高度明显低于术后1个月(P<0.05)。结论HA与β-TCP均具有良好的骨引导作用,可用于上颌窦底提升植骨中良好的骨替代材料,可维持种植体的长期稳定,值得推广使用。 展开更多
关键词 羟基磷灰石 Β-磷酸三钙 成骨效果 上颌窦提升 功能负载
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Determination of Effective Degree-Day for Supporting Chemical Control Against Cutworms (Lep. Noctuinae) in the Sugar Beet
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作者 Magdalena Jakubowska Felicyta Walczak JerzyJ6zefatLipa 《Journal of Agricultural Science and Technology(A)》 2012年第3期314-326,共13页
关键词 化学控制 地老虎 甜菜 有效度 测定 有效温度 短期预报方法 化学处理
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Neuroprotective effect of the Chinese medicine Tiantai No.1 and its molecular mechanism in the senescence-accelerated mouse prone 8 被引量:4
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作者 Ying-hong Li Xu-sheng Wang +5 位作者 Xiao-lin Chen Yu Jin Hong-bo Chen Xiu-qin Jia Yong-feng Zhang Zheng-zhi Wu 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第2期301-306,共6页
Tiantai No.1, a Chinese medicine predominantly composed of powdered Rhizoma Gastrodiae, Radix Ginseng, and Ginkgo leaf at a ratio of 2:1:2 and dissolved in pure water, is neuroprotective in animal models of various ... Tiantai No.1, a Chinese medicine predominantly composed of powdered Rhizoma Gastrodiae, Radix Ginseng, and Ginkgo leaf at a ratio of 2:1:2 and dissolved in pure water, is neuroprotective in animal models of various cognitive disorders, but its molecular mechanism remains unclear. We administered Tiantai No.1 intragastrically to senescence-accelerated mouse prone 8(SAMP8) mice(a model of Alzheimer's disease) at doses of 50, 100 or 150 mg/kg per day for 8 weeks and evaluated their behavior in the Morris water maze and expression of Alzheimer's disease-related proteins in the brain. Tiantai No.1 shortened the escape latency in the water maze training trials, and increased swimming time in the target quadrant during the spatial probe test, indicating that Tiantai No.1 improved learning and memory in SAMP8 mice. Immunohistochemistry revealed that Tiantai No.1 restored the proliferation potential of Ki67-positive cells in the hippocampus. In addition, mice that had received Tiantai No.1 had fewer astrocytes, and less accumulation of amyloid-beta and phosphorylated tau. These results suggest that Tiantai No.1 is neuroprotective in the SAMP8 mouse model of Alzheimer's disease and acts by restoring neuronal number and proliferation potential in the hippocampus, decreasing astrocyte infiltration, and reducing the accumulation of amyloid-beta and phosphorylated tau. 展开更多
关键词 nerve regeneration neuroprotective effects Alzheimer's disease Tiantai No.1 SAMP8 amyloid-beta autophagy-lysosome pathway ubiquitin proteasome pathway tau phosphorylation neuronal apoptosis astrocytosis neural regeneration
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β受体阻滞剂治疗婴幼儿血管瘤的最新现状
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作者 孙培培 彭威 +1 位作者 谢明峰 刘潜 《赣南医学院学报》 2023年第5期464-469,484,共7页
婴幼儿血管瘤是婴幼儿时期最常见的良性肿瘤,因其生长于头颈面部会造成面部畸形,影响患者身心健康,过去采用激素、手术等治疗,因遗留损害、并发症及复发率较高,使得临床治疗困难。自2008年以来,普萘洛尔作为一种非选择性β受体阻滞剂被... 婴幼儿血管瘤是婴幼儿时期最常见的良性肿瘤,因其生长于头颈面部会造成面部畸形,影响患者身心健康,过去采用激素、手术等治疗,因遗留损害、并发症及复发率较高,使得临床治疗困难。自2008年以来,普萘洛尔作为一种非选择性β受体阻滞剂被报道可以用于治疗婴幼儿血管瘤后,虽其机制尚不明确,但其肯定的疗效和较小的不良反应受到人们广泛关注,后大量报道多种多类β受体阻滞剂治疗婴幼儿血管瘤均有明显效果,常见的β受体阻滞剂有普萘洛尔、阿替洛尔、纳多洛尔、噻吗洛尔等,用药方法包括口服、外用、联合等,这使得β受体阻滞剂治疗婴幼儿血管瘤的同时带来了一些困惑,如何选择药物及用法成为临床治疗的难题。本文拟对近年来β受体阻滞剂治疗婴幼儿血管瘤的疗效、方法、不良反应进行分析与总结,为临床治疗婴幼儿血管瘤用药提供参考。 展开更多
关键词 婴幼儿血管瘤 Β受体阻滞剂 疗效 不良反应
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高能量电子激发比压阿尔芬本征模的全域模拟研究
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作者 包健 张文禄 李定 《物理学报》 SCIE EI CAS CSCD 北大核心 2023年第21期157-166,共10页
采用自主开发的本征值程序MAS,基于朗道流体-漂移动理学混合物理模型,针对近期实验上观测到的高能量电子激发比压阿尔芬本征模(e-BAE)开展动理学模拟研究.通过在全域环几何位形下非微扰求解e-BAE色散关系,得到了e-BAE实频率、增长率和... 采用自主开发的本征值程序MAS,基于朗道流体-漂移动理学混合物理模型,针对近期实验上观测到的高能量电子激发比压阿尔芬本征模(e-BAE)开展动理学模拟研究.通过在全域环几何位形下非微扰求解e-BAE色散关系,得到了e-BAE实频率、增长率和模结构随环向模数的变化特征,并发现e-BAE在高能量电子密度-温度参数空间下存在不稳定岛,而在传统微扰理论下则不存在不稳定岛.进一步分析了高能量电子非微扰效应对e-BAE模结构对称性破缺的影响,结果表明:增大高能量电子温度可以引起显著的极向对称性破缺;移动高能量电子密度剖面使其驱动强度关于有理面不对称时,e-BAE模结构产生径向对称性破缺,并且扰动幅度在平行波数谱空间下分布不对称,从而引起等离子体自发旋转.本文研究结果为理解实验上e-BAE的激发与传播特征具有参考意义. 展开更多
关键词 高能量电子 比压阿尔芬本征模 非微扰效应 对称性破缺
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