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Physical Diffusion and Electron-transfer Dynamics of Electroactive Solutes in Polymer Electrolytes Ⅰ. Effect of the Nature of Electroactive Solutes
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作者 Li Ming DING Hua Fang ZHOU Zhong SHI and Shao Jun DONG(Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第9期825-828,共4页
The diffusion coefficients(Dapp) and the heterogeneous electron-transfer rate constants(ks)for ferrocene and its seven derivatives in MPEG/LiClO4 electrolyte were determined by using steadystate voltammetry. The two p... The diffusion coefficients(Dapp) and the heterogeneous electron-transfer rate constants(ks)for ferrocene and its seven derivatives in MPEG/LiClO4 electrolyte were determined by using steadystate voltammetry. The two parameters increase with increasing temperature, indicating Arrhenius behavior. The effects of the nature of electroactive solute molecules on Dapp, ks, and the half-wave potentials(E1/2) are discussed. 展开更多
关键词 nature Physical Diffusion and Electron-transfer Dynamics of Electroactive Solutes in Polymer Electrolytes effect of the nature of Electroactive Solutes
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Comparing the difference in enhancement of kokumi-tastingγ-glutamyl peptides on basic taste via molecular modeling approaches and sensory evaluation 被引量:3
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作者 Juan Yang Jing Guo +4 位作者 Ruijie Mai Hao Dong Chun Cui Xiaofang Zeng Weidong Bai 《Food Science and Human Wellness》 SCIE 2022年第6期1573-1579,共7页
γ-Glutamyl peptides can enhance basic taste sensations such as saltiness,sweetness,and umaminess,while the molecular mechanism and the difference in taste enhancement remain elusive.Thus,two complex conformations:tas... γ-Glutamyl peptides can enhance basic taste sensations such as saltiness,sweetness,and umaminess,while the molecular mechanism and the difference in taste enhancement remain elusive.Thus,two complex conformations:taste type 1 receptor 1(T1 R1)-MSG and taste type 1 receptor 2(T1 R2)-sucrose were constructed to form binding receptors.These peptides showed affinity for the two receptors,but a higher affi nity scores and more binding amino acid residues for the T1 R1-MSG receptor,implying that they may exhibit a higher umami-enhancing effect.Thereinto,γ-glutamyl alanine(γ-EA)displayed the highest affi nity for the two receptors through mobilizing multiple amino acid residues to form hydrophobic and hydrogen bonds,indicating it had the highest enhancement for umaminess and sweetness among these peptides.Sensory evaluation demonstrated the enhancement ofγ-EA on umaminess was superior to that of sweetness.Generally,γ-glutamyl peptides could enhance basic taste sensation via activating taste receptor,and exhibited a highest umami-enhancing effect. 展开更多
关键词 γ-Glutamyl peptides taste-enhancing effect Molecular mechanism taste type 1 receptor 1 taste type 1 receptor 2
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Effectiveness of Nature Reserves for Natural Forests Protection in Tropical Hainan: a 20 Year Analysis 被引量:4
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作者 YU Bowei CHAO Xuelin +2 位作者 ZHANG Jindong XU Weihua OUYANG Zhiyun 《Chinese Geographical Science》 SCIE CSCD 2016年第2期208-215,共8页
The establishment of nature reserves is a key approach for biodiversity conservation worldwide. However, there is a lack of unified methodology to evaluate the effectiveness of nature reserves, particularly in China, ... The establishment of nature reserves is a key approach for biodiversity conservation worldwide. However, there is a lack of unified methodology to evaluate the effectiveness of nature reserves, particularly in China, the world′s most populous nation supporting some of the most valuable biodiversity hotspots in the world. In this study, we conducted a long-term and large-scale analysis of the effectiveness of 20 of the earliest nature reserves established in Hainan Province, an island home to among the highest concentration of plants and animals in China. Remote sensing imagery from 1988, 1998, and 2008 were analyzed to investigate the temporal and spatial changes of natural forests in these nature reserves and surrounding areas. We also conducted transition matrix analysis and principle component analysis to identify the driving factors that affect the protection effectiveness of nature reserves. The results were as follows: 1) During the 20-year period from 1988 to 2008, natural forests coverage of the 20 studied nature reserves dropped 2.34 percentage points, whereas the natural forests coverage dropped 11.31 percentage points in a 0–5 km outside reserve buffer and 9.36 percentage points in a 5–10 km outside reserve buffer, indicating a significant inhibitory effect of the nature reserves on the loss of natural forests. 2) Natural forests coverage dropped in 60% of the studied nature reserves during the 20-year period, suggesting a poor protection effectiveness of these reserves, while the coverage proportion showed some increase(0%/yr–5%/yr) in other reserves. 3) Expansion of rubber and pulp forests as part of a booming economy were the main factors affecting the effectiveness of the nature reserves for conserving natural forests in Hainan Province. The results of this study provide an important empirical basis for the protection of natural forests in Hainan Province, which can be used as a blueprint for nature reserve evaluation in other places in China. 展开更多
关键词 nature reserve natural forests reserve effectiveness Hainan Province China
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Effectiveness of Firewise Approach(FWA)in Controlling Forest Fire:A Case of Uluguru Nature Forest Reserve(UNFR),Morogoro,Tanzania
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作者 Pilly Joseph Kagosi Siwa Ernest Nkya +1 位作者 Chelestino Peter Balama Innocent Hamisi Babili 《Journal of Agricultural Science and Technology(B)》 2020年第3期175-185,共11页
Forest fire has received considerable attention in literature because it is considered one of the most common factors causing disturbances in ecosystems and at the same time considered vital in maintaining ecosystems.... Forest fire has received considerable attention in literature because it is considered one of the most common factors causing disturbances in ecosystems and at the same time considered vital in maintaining ecosystems.Firewise Approach(FWA)has been proposed and used for controlling forest fire and achieving sustainable forest management.The approach requires involvement of communities in managing forest fire incidences in reserved forests.Despite considerable period since FWA has been practiced,there is insufficient scholarly knowledge on effectiveness of the approach in managing forest fire.This paper examines the effectiveness of FWA in managing forest fires in Uluguru Nature Forest Reserve(UNFR).The study employed cross-section research design that involved quantitative and qualitative data collection.The data were analysed using Statistical Package for Social Science(SPSS)software and content analysis.The study found alternating periods:the period of overall decrease of wildfire incidences within initial five years of practising the approach.The study concludes that the FWA is useful in reducing forest fire incidences during early period of practising the approach and another period of huge fire occurrence beyond five years.However,the FWA has challenges of sustaining successes in controlling forest fires including limited fire management training to common community.The study recommends sustaining communities’trainings on forest fire management. 展开更多
关键词 effectiveness of firewise approach controlling forest fire Uluguru nature Forest Reserve.
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A Study of the People’s Nature in Woodcuts During the Anti-Japanese War in Shanxi
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作者 ZHANG Tong-yuan 《Journal of Literature and Art Studies》 2024年第11期1032-1040,共9页
The anti-Japanese woodcuts focus on the red revolutionary culture and describe the connotation of the Anti-Japanese War era,which is self-evident in the commemorative value of China’s revolutionary struggle history.F... The anti-Japanese woodcuts focus on the red revolutionary culture and describe the connotation of the Anti-Japanese War era,which is self-evident in the commemorative value of China’s revolutionary struggle history.For example,in Shanxi,China,woodcut art activities and social practice promotion activities organized around the theme of the Anti-Japanese War are also everywhere,which all show the people’s nature of the Chinese people during the revolutionary struggle from the two aspects of the red culture of the Anti-Japanese War and traditional art and culture,and its humanistic connotation is quite profound.In this paper,we first introduce the historical origin of woodcut during the Anti-Japanese War,and then show the people’s value connotation of woodcut art activities in Shanxi.This paper mainly discusses the image narration,language and picture narration and construction significance of woodcuts in Shanxi’s War of Resistance,fully reveals the narrative nature of image media,strives to arouse people’s recognition of this period of Shanxi’s War of Resistance culture and history,and reflects the realistic value and significance of Shanxi’s War of Resistance Woodcuts art activities. 展开更多
关键词 people’s nature Shanxi anti-Japanese woodcarving image media narrative synergistic effect construction significance humanistic cultural identity
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Assessment of effectiveness of nature reserves on the Tibetan Plateau based on net primary production and the large sample comparison method 被引量:6
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作者 张镱锂 胡忠俊 +7 位作者 祁威 吴雪 摆万奇 李兰晖 丁明军 刘林山 王兆锋 郑度 《Journal of Geographical Sciences》 SCIE CSCD 2016年第1期27-44,共18页
Twenty-one typical coupled large samples were chosen from areas within and surrounding nature reserves on the Tibetan Plateau using the large sample comparison method(LSCM).To evaluate the effectiveness of the nature ... Twenty-one typical coupled large samples were chosen from areas within and surrounding nature reserves on the Tibetan Plateau using the large sample comparison method(LSCM).To evaluate the effectiveness of the nature reserves in protecting the ecological environment,the alpine grassland net primary production(NPP) of these coupled samples were compared and the differences between them before and after their establishment as protected areas were analyzed.The results showed that:(1) With respect to the alpine grassland NPP,the ecological and environmental conditions of most nature reserves were more fragile than those of the surrounding areas and also lower than the average values for the Tibetan Plateau.(2) Of the 11 typical nature reserves selected,the positive trend in the NPP for Manzetang was the most significant,whereas there was no obvious trend in Taxkorgan.With the exception of Selincuo,the annual NPP growth rate in the nature reserves covered by alpine meadow and wetland was higher than that in nature reserves consisting of alpine steppe and alpine desert.(3) There were notable findings in 21 typical coupled samples:(a) After the establishment of the nature reserves,the annual rate of increase in the NPP in 76% of samples inside nature reserves and 82% of samples inside national nature reserves was higher than that of the corresponding samples outside nature reserves.(b) The effectiveness of ecological protection of the Mid-Kunlun,Changshagongma,Zoige and Selincuo(Selin Co) nature reserves was significant; the effectiveness of protection was relatively sig-nificant in most parts of the Sanjiangyuan and Qiangtang nature reserves,whereas in south-east Manzetang and north Taxkorgan the protection effectiveness was not obvious.(c) The ecological protection effectiveness was significant in nature reserves consisting of alpine meadow,but was weak in nature reserves covered by alpine steppe.This study also shows that the advantage of large sample comparison method in evaluating regional ecology change.Careful design of the samples used,to ensure comparability between the samples,is crucial to the success of this LSCM. 展开更多
关键词 nature reserves protection effectiveness large sample comparison method net primary production Tibetan Plateau
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An Analysis of Private Placement, Nature of Controlling Stake and Industrial Upgrading Effect
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作者 YAN Wu LI Jia LIU Binbin 《当代财经》 CSSCI 北大核心 2015年第S1期77-91,共15页
This paper aims to discuss and analyze the distribution characteristics of the private placement among different regions and different industries by state-owned and private holding enterprises as well as the changed e... This paper aims to discuss and analyze the distribution characteristics of the private placement among different regions and different industries by state-owned and private holding enterprises as well as the changed earning capacities of the capital before and after the placement. Taking the private placement financing data of the listed companies during the period of 2006-2011 in China's A-share markets as the sample, this study adopts the panel data model to conduct a quantitative analysis of the industrial upgrading effect of the private placement by listed companies with different holding natures. The empirical results show that though the private placement by the state-owned and private holding enterprises has not significantly improved the Clark index in any region, the private placement by private holding companies has significantly improved the growth rate of the tertiary industry in the eastern region. While reducing the proportion of the tertiary industry in GDP in the central and western regions, it has also improved the growth rate of the secondary industry and its proportion in GDP in that region to a larger extent. Yet the private placement of state-owned enterprises has no significant effect on the industrial upgrading path in any region except that it helped to raise the proportion of the secondary industry in GDP a little in the eastern region. 展开更多
关键词 PRIVATE PLACEMENT nature of controlling STAKE INDUSTRIAL UPGRADING effect.
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Influence of medications on taste and smell 被引量:3
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作者 Susan S. Schiffman 《World Journal of Otorhinolaryngology-Head and Neck Surgery》 2018年第1期84-91,共8页
Medications frequently have chemosensory side effects that can adversely affect compliance with medical treatment regimens. Hundreds of drugs have been reported to induce unpleasant tastes and/or odors as well as alte... Medications frequently have chemosensory side effects that can adversely affect compliance with medical treatment regimens. Hundreds of drugs have been reported to induce unpleasant tastes and/or odors as well as altered chemosensations when administered alone or in combination with other medications. Some chemosensory complaints are due to the sensory properties of the drug itself such as aversive bitter and metallic tastes. However, most chemo-sensory side effects of drugs are due to alterations in the transduction pathways, biochemical targets, enzymes, and transporters by the offending medications. Studies of chemosensory perception in medicated older individuals have found that taste and smell loss is greatest for those consuming the largest number of prescription drugs. There are no standard treat-ments for drug-induced chemosensory disorders because each drug has unique biological ef-fects. However, there are a few treatment options to ameliorate chemosensory alterations including addition of simulated flavors to food to compensate for losses and to override offend-ing tastes and smells. 展开更多
关键词 taste DISORDERS Smell DISORDERS CHEMOSENSORY side effects of drugs Drug-drug interactions BITTER taste Metallic taste
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Spatio-temporal analysis of the human footprint in the Hengduan Mountain region:Assessing the effectiveness of nature reserves in reducing human impacts 被引量:2
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作者 YIN Le DAI Erfu +3 位作者 ZHENG Du WANG Yahui MA Liang TONG Miao 《Journal of Geographical Sciences》 SCIE CSCD 2020年第7期1140-1154,共15页
Mapping the human footprint(HF)makes it possible to quantify human influence,which has had an unprecedented impact on the global ecosystem.Using five categories of human pressure data,this study mapped the HF of the H... Mapping the human footprint(HF)makes it possible to quantify human influence,which has had an unprecedented impact on the global ecosystem.Using five categories of human pressure data,this study mapped the HF of the Hengduan Mountain region and assessed the effectiveness of nature reserves in reducing human impacts.The results showed that the HF of the Hengduan Mountain region was generally higher in the south and lower in the north.The HF increased by 11.24%over the past 25 years,with faster growth in the southeast.The HF growth rate in nature reserves was much lower than that across the region,which indicated that nature reserves played an important role in reducing the impact of human pressure.A study of Baimaxueshan nature reserve found that establishing nature reserves could effectively reduce the impact of human activities,and no"leakage"occurred.Population growth was an important reason for the increased HF in nature reserves.The development of ecotourism in nature reserves must be based on ecological protection.Strengthening the long-term monitoring,evaluation,and management of nature reserves is a basic requirement for their long-term development. 展开更多
关键词 human influence human footprint nature reserves effectIVENESS
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Assessing the effectiveness of protecting reserves for nature assets in China 被引量:1
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作者 WEI Dongying LUO Zunlan +2 位作者 LIJunsheng WANG Wei ZHANG Mengmeng 《Journal of Geographical Sciences》 SCIE CSCD 2015年第4期417-427,共11页
Evaluating the effectiveness of protecting nature assets is a vital component of responsive, pro-active management of protected areas. It is important to protect reserves of geological (including fossils) assets as ... Evaluating the effectiveness of protecting nature assets is a vital component of responsive, pro-active management of protected areas. It is important to protect reserves of geological (including fossils) assets as a means to also protect national and natural heritage. At the end of 2013, 2669 protected areas had been established in China and 123 of them are reserves for nature assets. This paper builds an evaluation framework for protection effectiveness of these assets. The current elements and characteristics for effective protection are analyzed, along with an analysis of existing problems so as to construct a scientific approach to protect these assets. The influencing elements and characteristics for effective protection of nature asset reserves are included in an index evaluation system for effective protection in such areas, which contains four parts-target layer, evaluation criteria, evaluation indexes, and evaluation parameters-based on related documents and files. For the target layer, it includes nature asset evaluation and management evaluation. In the end, it is discussed how to build a comprehensive evaluation model and achieve an effective quantitative evaluation. 展开更多
关键词 nature asset reserve evaluation of protection effectiveness geological assets framework
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Medical plant extracts and natural compounds with a hepatoprotective effect against damage caused by antitubercular drugs: A review 被引量:4
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作者 María Adelina Jiménez-Arellanes Gabriel Alfonso Gutiérrez-Rebolledo +1 位作者 Mariana Meckes-Fischer Rosalba León-Díaz 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2016年第12期1116-1125,共10页
Drug-induced liver injury encompasses a spectrum of diseases ranging from mild biochemical abnormalities to acute liver failure; example of this scenery is hepatotoxicity caused by the first-line antituberculous drugs... Drug-induced liver injury encompasses a spectrum of diseases ranging from mild biochemical abnormalities to acute liver failure; example of this scenery is hepatotoxicity caused by the first-line antituberculous drugs isoniazid, rifampin and pyrazinamide, which are basic for treatment of drug-sensible and drug-resistant tuberculosis. In the search for pharmacological alternatives to prevent liver damage, antitubercular drugs have been the subject of numerous studies and published reviews, a great majority of them carried out by Asian countries. At the same time, hepatoprotectors from plant source are now emerging as a possible alternative to counteract the toxic effects of these therapeutic agents. The present review aims to highlight the most recent studies on the subject, based information published in scientific databases such as Scopus and Pub Med. 展开更多
关键词 Medicinal plants Hepatoprotective effect Antitubercular drugs-induced HEPATOTOXICITY Natural compounds
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Potential therapeutic effects of polyphenols in Parkinson's disease:in vivo and in vitro pre-clinical studies 被引量:2
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作者 Claudio Giuliano Silvia Cerri Fabio Blandini 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第2期234-241,共8页
Parkinson's disease is a neurodegenerative disorder characterized by a combination of severe motor and non-motor symptoms.Over the years,several factors have been discovered to play a role in the pathogenesis of t... Parkinson's disease is a neurodegenerative disorder characterized by a combination of severe motor and non-motor symptoms.Over the years,several factors have been discovered to play a role in the pathogenesis of this disease,in particular,neuroinflammation and oxidative stress.To date,the pharmacological treatments used in Parkinson's disease are exclusively symptomatic.For this reason,in recent years,the research has been directed towards the discovery and study of new natural molecules to develop potential neuroprotective therapies against Parkinson's disease.In this context,natural polyphenols have raised much attention for their important anti-inflammatory and antioxidant properties,but also for their ability to modulate protein misfolding.In this review,we propose to summarize the relevant in vivo and in vitro studies concerning the potential therapeutic role of natural polyphenols in Parkinson's disease. 展开更多
关键词 ALPHA-SYNUCLEIN ANTI-INFLAMMATORY ANTIOXIDANTS natural molecules NEUROPROTECTION Parkinson's disease POLYPHENOLS syntomatic effect
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The Antimutagenic and Anticarcinogenic Effects of Tea, Garllc and Other Natural Foods in China: A Review 被引量:4
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作者 CHEN JUNSHIInstitute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, 29 Nan WeiRoad, Beijing 100050, China 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1992年第1期1-17,共17页
It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, c... It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, cancer mortality rates for most cancers were found to be more than 20-fold greater in some counties in others (Table 1). Esophageal cancer rates for males are a few hundred fold greater in the highest county when compared with the lowest county. The mortality rate for all cancers combined for males is 21 fold greater in the county with the highest mortality than in the county with the lowest rate.According to Doll and Peto (1981), about one third of human cancer death is avoidable by appropriate modification of the diet. Therefore, diet is very likely to have an important part in causing these huge geographic variations. The possible role of various mutagens and carcinogens (e.g. afiatoxin, N-nitroso compounds) in locally produced and consumed foods has been strongly suggested and widely acknowledged, although much more evidence would be required to confirm their actual functions in human cancer. On the other hand, there are a few reports stating that the human diet also contains powerful antimutagens and anticarcinogens (Ames, 1983). The possible role of these two types of substances in causing the huge geographic variation of cancer risks remains elusive and inadequately explored. In order to make better use of these natural anticarcinogens in cancer prevention, it is important to elucidate their effects and mechanisms. The purpose of this paper is to summarize the available information on the antimutagenic and anticarcinogenic effects of natural foods in the Chinese diet, excluding the effects of essential nutrients, e.g. dietary fibers, vitamins and minerals. Most of the literature cited in this review was published by Chinese scientists. 展开更多
关键词 The Antimutagenic and Anticarcinogenic effects of Tea A Review Garllc and Other Natural Foods in China
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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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Large-scale gas accumulation mechanisms and reservoir-forming geological effects in sandstones of Central and Western China 被引量:1
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作者 LI Wei WANG Xueke +3 位作者 ZHANG Benjian CHEN Zhuxin PEI Senqi YU Zhichao 《Petroleum Exploration and Development》 2020年第4期714-725,共12页
Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects.Based on the geological theory and method of nat... Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects.Based on the geological theory and method of natural gas reservoir formation,this study examined the regional geological and structural background,formation burial evolution,basic characteristics of gas reservoirs,and fluid geology and geochemistry of typical petroliferous basins.The results show that the geological processes such as structural pumping,mudstone water absorption,water-soluble gas degasification and fluid sequestration caused by uplift and denudation since Himalayan stage all can form large-scale gas accumulation and different geological effects of gas accumulation.For example,the large-scale structural pumping effect and fluid sequestration effect are conducive to the occurrence of regional ultra-high pressure fluid and the formation of large-scale ultra-high pressure gas field;mudstone water absorption effect in the formation with low thickness ratio of sandstone to formation is conducive to the development of regional low-pressure and water free gas reservoir;the water-soluble gas degasification effect in large-scale thick sandstone can not only form large-scale natural gas accumulation;moreover,the degasification of water-soluble gas produced by the lateral migration of formation water will produce regional and regular isotopic fractionation effect of natural gas,that is,the farther the migration distance of water-soluble gas is,the heavier the carbon isotopic composition of methane formed by the accumulation. 展开更多
关键词 Central and Western China basins large-scale natural gas accumulation mechanism structural pumping effect mudstone water absorption effect water-soluble gas degasification effect fluid sequestration effect natural gas reservoir formation
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Effects of Food Diet Preparation Techniques on Radionuclide Intake and Its Implications for Individual Ingestion Effective Dose in Abeokuta, Southwestern Nigeria 被引量:1
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作者 Nnamdi Norbert Jibiri Tolulope Hadrat Abiodun 《World Journal of Nuclear Science and Technology》 2012年第3期106-113,共8页
The radioactivity measurements in food crops and their diet derivatives and farm soil samples from Abeokuta, one of the elevated background radiation areas in Nigeria have been carried out in order to determine the co... The radioactivity measurements in food crops and their diet derivatives and farm soil samples from Abeokuta, one of the elevated background radiation areas in Nigeria have been carried out in order to determine the concentration levels of natural radionuclides (40K, 226Ra and 232Th). The activity concentrations of the natural radionuclides in the samples were determined via gamma-ray spectrometry using a 76 mm × 76 mm NaI(Tl) detector. Different common food crops representing the major sources of dietary requirements to the local population were collected for the measurements. The collected food crops were prepared into their different derivable composite diets using preparation techniques locale to the population. Using available food consumption data and the activity concentrations of the radionuclides, the ingestion effective doses were evaluated for the food crops and diet types per preparation techniques. For the tuberous food crop samples, the annual ingestion effective doses in the raw and different composite diets were 0.02 - 0.04 μSv and cumulatively 0.04 - 0.05 μSv while in the non-tuberous crops the doses were 0.44 - 0.70 μSv and cumulatively greater than 1 μSv respectively. Results of the study indicate that method of diet preparation is seen to play a major role in population ingestion dose reduction especially for tuberous crops than in non-tuberous crops. The study also showed that more ingestion dose could be incurred in diets prepared by roasting techniques. The result of the study will serve as a useful radiometric data for future epidemiological studies in the area and for food safety regulations and policy implementations in the country. 展开更多
关键词 Natural Radionuclides RADIONUCLIDE INTAKE Gamma Ray Spectroscopy FOOD CROPS Radiation effective Ingestion Dose DIET Preparation Techniques
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Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19 被引量:1
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作者 Zhiding ZHANG Xu YUE +3 位作者 Hao ZHOU Jun ZHU Yadong LEI Chenguang TIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期84-96,共13页
The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).Whil... The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming. 展开更多
关键词 diffuse radiation fertilization effects anthropogenic aerosols natural aerosols pan-Arctic net primary productivity
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The Coupled Effect of Temperature Changes and Damage Depth on Natural Frequencies in Beam-Like Structures
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作者 Tareq Al-hababi Nizar Faisal Alkayem +3 位作者 Li Cui Shixiang Zhang Cong Liu Maosen Cao 《Structural Durability & Health Monitoring》 EI 2022年第1期15-35,共21页
A significant amount of research is concerned with dynamic modal parameters for damage detection of structural conditions due to their simplicity in use and feasibility.However,their use for damage detection should be... A significant amount of research is concerned with dynamic modal parameters for damage detection of structural conditions due to their simplicity in use and feasibility.However,their use for damage detection should be performed with special attention,particularly in operational and environmental conditions subjected to temperature changes.Beams in construction industries experience different loading types,such as temperature changes leading to crack initiation and propagation.Changed physical and dynamic properties such as natural frequencies and mode shapes indicate that damage has occurred within the structures.In this study,vibration analysis of cantilever and cantilever simply supported beams has been carried out on intact and damaged beams to investigate the coupled effect of temperature changes and damage depth on natural frequencies.A numerical analysis of beams is completed using ANSYS software.The results of numerical simulation are validated using two other studies from literature.Numerical results revealed that in order to perform a successful damage assessment using the frequency shift,the vibration modes should be selected properly.In addition,an increase in temperature results in a decrease in structural frequencies.The assessment of the effect of damage depth on natural frequencies also confirms that when damage depth is increased,there is a significant decrease in natural frequency responses. 展开更多
关键词 Temperature effect damage depth natural frequency BEAM damage detection modal analysis
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Assessing the Effect of Natural Controls and Land Use Change on Sediment Yield in a Major Andean River:The Magdalena Drainage Basin,Colombia 被引量:4
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作者 Juan Dario +5 位作者 Restrepo James P. M. Syvitski 方海燕(译) 《AMBIO-人类环境杂志》 2006年第2期65-74,4,共10页
马格达莱纳河是哥伦比亚安第斯山区的一个世界级的河流网络,该河流年产沙量约为150Mt,是全世界10大主要产沙河流之一。在本研究中,我们探讨主要自然因子和人类活动对马格达莱纳河流域产沙模式的影响,重建该区森林砍伐和农业活动时... 马格达莱纳河是哥伦比亚安第斯山区的一个世界级的河流网络,该河流年产沙量约为150Mt,是全世界10大主要产沙河流之一。在本研究中,我们探讨主要自然因子和人类活动对马格达莱纳河流域产沙模式的影响,重建该区森林砍伐和农业活动时空模式,探讨土地利用变化与产沙趋势的关系。我们的研究结果表明,整个马格达莱纳河流域的产沙量可以用自然变量(包括径流量和最大河水流量)来解释。这两个因子解释了产沙量58%的变化。含沙率和土地利用的时间分析表明,在过去10~20年里流域侵蚀呈现增加的趋势。许多人类活动的影响,包括森林覆被在20年里减小了近40%.农业和牧场增加了65%、土壤保持差、开矿活动,以及城市化的加速,都促进了该地区域尺度上产沙量的增加。 展开更多
关键词 Assessing the effect of Natural Controls and Land Use Change on Sediment Yield in a Major andean River
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Implementation of the Belt and Road Initiative: Its Effect on and Implications for the Development of China's Natural Gas Industry
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作者 Xiong Wei 《China Oil & Gas》 CAS 2017年第2期44-50,116-122,共14页
This paper analyzes the origin of the Belt and Road Initiative, the role of China's market-oriented development of natural gas in promoting the Belt and Road Initiative, and the possibilities of natural gas cooper... This paper analyzes the origin of the Belt and Road Initiative, the role of China's market-oriented development of natural gas in promoting the Belt and Road Initiative, and the possibilities of natural gas cooperation between China and countries along the Belt and Road. In this paper, the implementation of the natural gas strategy under the Belt and Road Initiative and how it will promote the development of the natural gas industry chain are reviewed. The risks of implementing the Belt and Road Initiative are analyzed, especially in terms of the pricing mechanism, geopolitical risks, and seasonal risks. 展开更多
关键词 Belt and Road Natural Gas IMPACTS effect
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