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Antifungal Effect of Streptomyces 702 Antifungal Monomer Component DZP8 on Rhizoctonia solani and Magnaporthe grisea 被引量:1
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作者 芦慧 涂晓嵘 +2 位作者 徐佳 冯华根 涂国全 《Agricultural Science & Technology》 CAS 2012年第11期2370-2374,2378,共6页
The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia ... The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia solani and on the mycelium growth, conidial formation, germination, appressorium formation of Magnaporthe grisea. The results showed that the antifungal monomer component DZP8 has strong antifungal effect on both the R. solani and M. grisea. The EC50 and EC90 of DZP8 were 1.81 and 3.35 μg/ml on Ft. solani respectively, and 37.01 and 136.21 μg/ml on M. grisea respectively. Under the treatment of 48.01 μg/ml DZP8, the sclerotium formation rate of R. solani was just 39.21%, the formation time delayed by 216 h and the dry weight decreased by 81.37% in comparison the con- trol; and 33.51 μg/ml DZP8 significantly inhibited the sclerotium germination. In the presence of 160.08 μg/ml DZP8, the sporulation of M. grisea was just 9.29% of control sample; 20.14 μg/ml DZP8 inhibited the conidial germination suppression rate by 95.16%, and the appressorium formation by 100%. 展开更多
关键词 Streptomyces 702 Monomer component DZP8 Rhizoctonia solani Mag-naporthe grisea Antifungal effect
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EMPIRICAL BAYES TEST PROBLEMS OF VARIANCE COMPONENTS IN RANDOM EFFECTS MODEL 被引量:3
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作者 韦来生 张伟平 《Acta Mathematica Scientia》 SCIE CSCD 2005年第2期274-282,共9页
Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that t... Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that the proposed EB decision rules are asymptotically optimal with convergence rates near O(n-1/2). Finally, an example concerning the main result is given. 展开更多
关键词 Empirical Bayes test variance components random effects model convergence rates
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Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System 被引量:1
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作者 Hua ZHU Piaoling HUANG +3 位作者 Wenqi YANG Anda WEI Ruiting HE Zhonghua DAI 《Medicinal Plant》 CAS 2019年第6期39-41,共3页
In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,this paper summarized the pharmacological effects of the ... In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,this paper summarized the pharmacological effects of the active components of Gastrodiae Rhizoma.The pharmacological effects of the active components of Gastrodiae Rhizoma on the central nervous system include improving the ability of learning and memory,analgesia,sedation and hypnosis,anticonvulsant,anti-aging,anti-anxiety and neuroprotective effects.The active components of Gastrodiae Rhizoma have certain curative effect in the treatment of some diseases of the central nervous system.At present,it has been widely used clinically.There are no toxic and side effects at conventional doses,and it is worth popularizing and applying. 展开更多
关键词 Gastrodiae Rhizoma ACTIVE componentS CENTRAL nervous system PHARMACOLOGICAL effectS
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Effects of acrous gramimeus and its main component alpha-asarone on the reactivity and convulsive threshold of immature rats to electric stimulation 被引量:3
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作者 Libin Yang Shulei Li +1 位作者 Yuhong Wang Yanzhi Huang 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第1期78-80,共3页
BACKGROUND: The traditional Chinese medicine acrous gramimeus is the dry rhizome of Acrous gramimeus Soland, a kind of Araceae familial perennial herb, which has a sedation action, anticonvulsant and antiepileptic ef... BACKGROUND: The traditional Chinese medicine acrous gramimeus is the dry rhizome of Acrous gramimeus Soland, a kind of Araceae familial perennial herb, which has a sedation action, anticonvulsant and antiepileptic effect. Its effective component has not been known yet, and α-asarone, the major component of the volatile oil extracted from acrous gramineus, has been supposed to play a necessary role in it. OBJECTIVE: To explore the effects of acrous gramimeu and α-asarone on the reactivity and convulsive threshold to electric stimulation in immature rats, furthermore, attempt to definitize the anticonvulsant effect of α-asarone. DESIGN: A randomized controlled study.SETTINGS: Department of Pediatrics, First Hospital of Jilin University; Department of Histology and Embryology, School of Basic Medical Sciences of Jilin University; Department of Neurology, First Clinical Hospital affiliated to Harbin Medical University; Department of Internal Medicine, Children's Hospital of Changchun City. MATERIALS : Seventy 3-week immature Wistar rats (either males or females) of 34-40 g were used. Acrous gramimeu (1 g/bag, the content of α-oasarone was 0.046 26%-0.070 16%) with the batch number of 0307113 was provided by Tianjiang Medicine Company Limited, Jiangyin City. α-asarone tablet (60 mg per tablet) with the batch number of 030219 was provided by Tianwei Pharmaceutical Factory, Shenyang City. α-asarone injectable preparation (2 mL per piece) with the batch number of 030105 was provided by Shuanghe Medicine Limited Company, Beijing City. METHODS : The experiments were carried out in the Neurological Laboratory of the First Hospital of Jilin University between August and October in 2004.① The 70 rats were randomly divided into intragastric subset and intraperitoneal subset. The intragastric subset included four groups of control, phenobarbital sodium, acrous gramimeu and α-asarone; the intraperitoneal subset included three groups of control, phenobarbital sodium and α-asarone. There were 10 rats per group. ② In the intragastric subset, different group was treated with saline (1 mL for each time, phenobarbital sodium (18 mg/kg per day), acrous gramineu (2 350 mg/kg per day) and α-asarone (29 mg/kg per day) respectively twice every day for 5 days. In the intraperitoneal subset, different group was treated with saline (0.5 mL), phenobarbital sodium (29 mg/kg) and α-asarone (2.9 mg/kg) respectively. ③ Before and after administration for 5 days in the intragastric subset as well as before and after administration for about 1 hour in the intraperitoneal subset respectively, the rats were given electric stimulation with the NIHOM KOMDEM multifunctional electrophysiological recorder, and the reactivity and convulsive threshold to electric stimulation of the rats were recorded. MAIN OUTCOME MEASURES: The reactivity and convulsive threshold to electric stimulation in immature rats were compared. RESULTS: All the rats were involved in the analysis of results. ① Results for intragastric administration: Before intragastric administration, there were no obvious differences in the reactivity and convulsive threshold to electric stimulation among the groups (P 〉 0.05). After intragastric administration for 5 days, the reactivity and convulsive threshold to the electric stimulation had no obvious changes in the control group, but those were significantly higher than before administration in the drug administration groups (t=-3.317-7.401, P 〈 0.01), which were also obviously higher than those in the control group (t=3.027-8.941, P 〈 0.01), and those in the acrous gramimeu group and α-asarone group were not markedly different from those in the phenobarbital sodium group. ② Results for intraperitoneal injection: Before intraperitoneal injection, the reactivity and convulsive threshold to the electric stimulation had no obvious differences among the groups. After the intraperitoneal injection for 1 hour, the reactivity and convulsive threshold to the electric stimulation had no obvious change in the control group, but those were significantly higher than before administration in the drug administration groups (P 〈 0.01), which were also obviously higher than those in the control group (t=6.211-7.237, P 〈 0.01; t=4.085-5.633, P 〈 0.05), and there was no marked difference between α-asarone group and phenobarbital sodium group (P 〉 0.05).CONCLUSION : ① As effective anticonvulsants, both acrous gramineu and α-asarone can enhance the reactivity and convulsive threshold of immature rats to electric stimulation. ② As one of the major effective components against convulsion of acrous gramineu, α-asarone is equivalent to phenobarbital sodium. 展开更多
关键词 effects of acrous gramimeus and its main component alpha-asarone on the reactivity and convulsive threshold of immature rats to electric stimulation THAN
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Effect of chemical component on shape memory effect of Fe-Mn-Si-Ni-C-RE shape memory alloy
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作者 SI Naichao, JIA Zhihong, and QI Longbiao 《Rare Metals》 SCIE EI CAS CSCD 2004年第1期87-87,共1页
Effect of chemical component on shape memory effect (SME) of Fe-Mn-Si-Ni-C-RE shape memory alloys was studied by bent measurement, thermal cycle training, SEM etc. Results of study indicate that the alloys with high M... Effect of chemical component on shape memory effect (SME) of Fe-Mn-Si-Ni-C-RE shape memory alloys was studied by bent measurement, thermal cycle training, SEM etc. Results of study indicate that the alloys with high Mn content (25%) appeare better SME, especially in lower strain. SME improves evidently when Si is higher content, especially it’s range from 3% up to 4%. But brittleness of Fe-Mn-Si-Ni-C-RE alloy increases by increasing the Si content. SME of the alloy is weakening gradually as carbon content increases under small strain (3%). But in the condition of large strain (above 6%), SME of the alloy whose carbon content ranges from 0.1 % to 0.12% shows small decreasing range, especially of alloy with the addition of compound RE. 展开更多
关键词 chemical component Fe-Mn-Si-Ni-C-RE shape memory alloy shape memory effect STRAIN
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Effect of chemical component on shape memory effect of Fe-Mn-Si-Ni-C-RE shape memory alloy
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作者 NaichaoSi ZhihongJia LongbiaoQi 《Journal of University of Science and Technology Beijing》 CSCD 2004年第1期75-80,共6页
Effect of chemical component on shape memory effect (SME) of Fe-Mn-Si-Ni-C-REshape memory alloys was studied by bent measurement, thermal cycle training, SEM etc. Results ofstudy indicate that the alloys with high Mn ... Effect of chemical component on shape memory effect (SME) of Fe-Mn-Si-Ni-C-REshape memory alloys was studied by bent measurement, thermal cycle training, SEM etc. Results ofstudy indicate that the alloys with high Mn content (25%) appeare better SME, especially in lowerstrain. SME improves evidently when Si is higher content, especially it's range from 3% up to 4%.But brittleness of Fe-Mn-Si-Ni-C-RE alloy increases by increasing the Si content. SME of the alloyis weakening gradually as carbon content increases under small strain (3%). But in the condition oflarge strain (above 6%), SME of the alloy whose carbon content ranges from 0.1 % to 0.12% showssmall decreasing range, especially of alloy with the addition of compound RE. 展开更多
关键词 chemical component Fe-Mn-Si-Ni-C-RE shape memory alloy shape memory effect STRAIN
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Research Progress on Functional Components and Pharmacological Effects of Red Jujube ( Ziziphus jujuba Mill.)
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作者 Qian SHI 《Agricultural Biotechnology》 CAS 2023年第4期71-74,87,共5页
Red jujube(Ziziphus jujuba Mill.),as a traditional Chinese medicine and edible plant,has a long history and extensive uses.Red jujubes are not only widely used in the food industry and traditional Chinese medicine pre... Red jujube(Ziziphus jujuba Mill.),as a traditional Chinese medicine and edible plant,has a long history and extensive uses.Red jujubes are not only widely used in the food industry and traditional Chinese medicine preparations,but also have attracted widespread research interest due to their rich functional components and various pharmacological effects.This paper reviewed the main functional components of jujubes,including polysaccharides,triterpenoid saponins,organic acids and alkaloids,and discussed in detail the pharmacological effects of these components such as blood sugar-regulating,antioxidant,anti-inflammatory and anti-tumor effects.Furthermore,the paper also summarized the safety issues such as drug interactions and toxic side effects of jujubes,and prospected the future development direction of jujube research. 展开更多
关键词 JUJUBE Functional components Pharmacological effects
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Advances in Research of Chemical Components and Pharmacological Effects of Platycladus orientalis Leaves
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作者 Ruifeng ZHANG Yang ZENG +4 位作者 Likuan LIU Hongyu WANG Wenming ZUO Junyan ZHANG Jinping LI 《Medicinal Plant》 CAS 2021年第4期8-12,共5页
Platycladi Cacumen(Platycladus orientalis leaf)is a traditional Chinese medicine with a variety of medicinal values,and its efficacy has been recorded by many ancient books.Its chemical components mainly include flavo... Platycladi Cacumen(Platycladus orientalis leaf)is a traditional Chinese medicine with a variety of medicinal values,and its efficacy has been recorded by many ancient books.Its chemical components mainly include flavonoids,volatile oil,tannins and so on.Pharmacological studies have confirmed that P.orientalis leaves have various pharmacological effects such as antibacterial,anti-oxidant,anti-tumor,hair growth promoting and hemostatic effects.Through review of the research on the chemical components and pharmacological effects of P.orientalis leaves,this study is intended to provide reference for the research,development and utilization of P.orientalis. 展开更多
关键词 Platycladus orientalis Platycladi Cacumen Chemical components Pharmacological effects
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Technology for Extracting Effective Components from Fish Scale
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《Journal of Food Science and Engineering》 2017年第7期351-358,共8页
The research of the category and extraction methods of effective ingredients of fish scale was reviewed at home and abroad. The extraction process of fish scale was studied, including collagen, hydroxyapatite, lecithi... The research of the category and extraction methods of effective ingredients of fish scale was reviewed at home and abroad. The extraction process of fish scale was studied, including collagen, hydroxyapatite, lecithin, guanine etc. The different extraction methods and the components were analyzed. The research of effective ingredients of fish scales was reviewed as theory basis to further research and comprehensive development. 展开更多
关键词 Fish scale effective components COLLAGEN HYDROXYAPATITE LECITHIN guanine.
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EFFECTS OF S86019, AN ACTIVE COMPONENT FROM PURALIA LOB AT A, ON CELL DIFFERENTIATION AND CELL CYCLE TRAVERSE OF HL-60 CELLS
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作者 韩锐 焦鹭 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1990年第3期54-56,共3页
The effects of S86019, an active component from Puralia lobata, on the induction of cell differentiation and cell cycle traverse of HL-60 cells were described. It was shown that cell proliferation of HL-60 cells was i... The effects of S86019, an active component from Puralia lobata, on the induction of cell differentiation and cell cycle traverse of HL-60 cells were described. It was shown that cell proliferation of HL-60 cells was inhibited by S86019 in vitro. Under the action of S86019 the HL-60 cells were induced to differentiate into metamyelocytes, myelocytes and much matured cells with banded or segmented nucleus. Flow cytometry demonstrated that the cell population of HL-60 cells was blocked at G1 phase which resulted in the elevation of percentage of G1 cells and decrease of percentage of cells in S phase. Experimental results demonstrated that S86019 is an active inducer of cell differentiation in HL-60 cells. 展开更多
关键词 HL ON CELL DIFFERENTIATION AND CELL CYCLE TRAVERSE OF HL-60 CELLS effectS OF S86019 AN ACTIVE component FROM PURALIA LOB AT A
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Effect of Loading Paths on Hydroforming Tubular Square Components
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作者 Hongyang LI Shijian YUAN +3 位作者 Kun DAI Lihui LANG Xiaosong WANG Zhubin HE and Zhongren WANG School of Materials Science and Engineering, Harbin institute of Technology, Harbin 150001, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第1期158-,共1页
The influence of loading path on tube hydroforming process is discussed in this paper with finiteelement simulation. Four different loading paths are utilized in simulating the forming process of square tubular compo... The influence of loading path on tube hydroforming process is discussed in this paper with finiteelement simulation. Four different loading paths are utilized in simulating the forming process of square tubular component with hydroforming and the result of different loading path is presented. Among the result. the thickness distribution of bilinear loading path is the most uniform one. It shows that the increase of punch displacement in the stage of high pressure is beneficial to the forming of component for optimized Stress condition. 展开更多
关键词 effect of Loading Paths on Hydroforming Tubular Square components
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Prediction of Quality Markers(Q-Markers)for the Mongolian Medicine Naru-3 Based on Chemical Composition,Pharmacological Effects,and Network Pharmacology
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作者 Ying En Liang Xu Jiaqi Yu 《Journal of Clinical and Nursing Research》 2025年第1期1-10,共10页
Naru Sanwei Pill,also known as Naru-3,a Mongolian medicine originating from Zhigao Pharmacopoeia,is a classic prescription used in the treatment of rheumatism.It is composed of Terminalia chebula,processed Aconitum ku... Naru Sanwei Pill,also known as Naru-3,a Mongolian medicine originating from Zhigao Pharmacopoeia,is a classic prescription used in the treatment of rheumatism.It is composed of Terminalia chebula,processed Aconitum kusnezoffii Reichb.,and Piper longum,and is known for its effects in eliminating“mucus,”relieving pain,and reducing swelling,with significant efficacy in treating joint effusion and lumbar pain.In recent years,researchers have summarized its chemical components and pharmacological effects,and employed network pharmacology methods based on the core theory of Traditional Chinese Medicine quality markers(Q-Markers)to analyze and predict its markers.The results identified potential Q-Markers for Naru-3,providing a scientific basis for quality control and further research. 展开更多
关键词 Mongolian medicine Naru-3 Network pharmacology Quality markers Chemical components Pharmacological effects
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Comparison of REML and MINQUE for Estimated Variance Components and Predicted Random Effects
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作者 Nan Nan Johnie N. Jenkins +1 位作者 Jack C. McCarty Jixiang Wu 《Open Journal of Statistics》 2016年第5期814-823,共11页
Linear mixed model (LMM) approaches have been widely applied in many areas of research data analysis because they offer great flexibility for different data structures and linear model systems. In this study, emphasis... Linear mixed model (LMM) approaches have been widely applied in many areas of research data analysis because they offer great flexibility for different data structures and linear model systems. In this study, emphasis is placed on comparing the properties of two LMM approaches: restricted maximum likelihood (REML) and minimum norm quadratic unbiased estimation (MINQUE) with and without resampling techniques being included. Bias, testing power, Type I error, and computing time were compared between REML and MINQUE approaches with and without Jackknife technique based on 500 simulated data sets. Results showed that MINQUE and REML methods performed equally regarding bias, Type I error, and power. Jackknife-based MINQUE and REML greatly improved power compared to non-Jackknife based linear mixed model approaches. Results also showed that MINQUE is more time-saving compared to REML, especially with the use of resampling techniques and large data set analysis. Results from the actual cotton data analysis were in agreement with our simulated results. Therefore, Jackknife-based MINQUE approaches could be recommended to achieve desirable power with reduced time for a large data analysis and model simulations. 展开更多
关键词 Comparison of REML and MINQUE for Estimated Variance components and Predicted Random effects
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Ion adsorption components in liquid/solid systems 被引量:21
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作者 WU Xiao-fu HU Yue-li ZHAO Fang HUANG Zhong-zi LEI Dian 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第6期1167-1175,共9页
Experiments on Zn^2+ and Cd^2+ adsorptions on vermiculite in aqueous solutions were conducted to investigate the widely observed adsorbent concentration effect on the traditionally defined adsorption isotherm in the... Experiments on Zn^2+ and Cd^2+ adsorptions on vermiculite in aqueous solutions were conducted to investigate the widely observed adsorbent concentration effect on the traditionally defined adsorption isotherm in the adsorbate range 25--500 mg/L and adsorbent range 10--150 g/L. The results showed that the equilibrium ion adsorption density did not correspond to a unique equilibrium ion concentration in liquid phase. Three adsorbate/adsorbent ratios, the equilibrium adsorption density, the ratio of equilibrium adsorbate concentration in liquid phase to adsorbent concentration, and the ratio of initial adsorbate concentration to adsorbent concentration, were found to be related with unique values in the tested range. Based on the assumption that the equilibrium state of a liquid/solid adsorption system is determined by four mutually related components: adsorbate in liquid phase, adsorbate in solid phase, uncovered adsorption site and covered adsorption site, and that the equilibrium chemical potentials of these components should be equalized, a new model was presented for describing ion adsorption isotherm in liquid/solid systems. The proposed model fit well the experimental data obtained from the examined samples. 展开更多
关键词 adsorbent effect adsorbate/adsorbent ratio adsorption component chemical potential Zn^2+ Cd^2+ VERMICULITE
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Natural products and food components with anti-Helicobacter pylori activities 被引量:3
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作者 Hiroaki Takeuchi Vu Thu Trang +3 位作者 Norihito Morimoto Yoshie Nishida Yoshihisa Matsumura Tetsuro Sugiura 《World Journal of Gastroenterology》 SCIE CAS 2014年第27期8971-8978,共8页
The bacterial pathogen Helicobacter pylori (H. pylori) colonizes in over half of the world&#x02019;s population. H. pylori that establishes life-long infection in the stomach is definitely associated with gastro-d... The bacterial pathogen Helicobacter pylori (H. pylori) colonizes in over half of the world&#x02019;s population. H. pylori that establishes life-long infection in the stomach is definitely associated with gastro-duodenal diseases and a wide variety of non-gastrointestinal tract conditions such as immune thrombocytopenia. Triple therapy which consists of a proton pump inhibitor and combinations of two antibiotics (amoxicillin, clarithromycin or amoxicillin, metronidazol) is commonly used for H. pylori eradication. Recently, the occurrence of drug-resistant H. pylori and the adverse effect of antibiotics have severely weakened eradication therapy. Generally antibiotics induce the disturbance of human gastrointestinal microflora. Furthermore, there are inappropriate cases of triple therapy such as allergy to antibiotics, severe complications (liver and/or kidney dysfunction), the aged and people who reject the triple therapy. These prompt us to seek alterative agents instead of antibiotics and to develop more effective and safe therapy with these agents. The combination of these agents actually may result in lower a dose of antibiotics. There are many reports world-wide that non-antibiotic substances from natural products potentially have an anti-H. pylori agent. We briefly review the constituents derived from nature that fight against H. pylori in the literature with our studies. 展开更多
关键词 Anti-Helicobacter pylori effect Natural product Food component In vitro and in vivo effects Human health Helicobacter pylori treatment Combined effect
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The Influence of Some Key Parameters on Fatigue Life of Common Metallic Components 被引量:1
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作者 LIU Yi lun (College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China) 《Journal of Central South University》 SCIE EI CAS 2000年第3期159-161,共3页
The effect of key parameters on fatigue life of common metallic components, e.g. steel, aluminium alloy, has been analysed quantitatively. The influential coverage and degree of these parameters have been investigated... The effect of key parameters on fatigue life of common metallic components, e.g. steel, aluminium alloy, has been analysed quantitatively. The influential coverage and degree of these parameters have been investigated systematically, some phenomena which can′t be discovered with qualitative analysis method have been revealed, a series of valuable conclusions has been obtained, which would be very beneficial to fatigue resistant design and improvement of anti fatigue ability of metallic components. 展开更多
关键词 METALLIC material component FATIGUE LIFE KEY PARAMETER effect
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Impact of sampling interval on variance components of epoch-wise residual error in relative GPS positioning: A case study of a 40-km-long baseline
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作者 Darko Andic 《Geodesy and Geodynamics》 CSCD 2021年第5期368-380,共13页
The study presents sampling interval impacts on variance components of the epoch-wise residual errors in relative GPS positioning. In the variance components estimation process, the 2-way nested ANOVA method was used.... The study presents sampling interval impacts on variance components of the epoch-wise residual errors in relative GPS positioning. In the variance components estimation process, the 2-way nested ANOVA method was used. For that purpose, GPS observation data during four months at two permanent GPS stations, establishing a 40-km-long baseline as a part of the Montenegrin permanent network(Monte Pos), were used. The study results showed that there is no statistically significant impact of sampling interval changes on epoch-wise variance components related to the residual tropospheric and ionospheric delays(effect a) when it comes to such a baseline. However, it is not the case with epoch-wise variance components related to the interstation-distance-independent residual ‘far-field’ multipath effect(effect b). It turned out that the absolute values of relative differences of standard deviations of the effect a on the relative GPS coordinates(e, n and u) had maximum values 11.1%, 10.2% and 8.9%,respectively. Keeping the same order of presentation for the effect b, the values of 5.9%, 9.9% and 12.5%were obtained. In addition, absolute values of relative differences of standard deviations of horizontal and vertical position had maximum values of 3.8% and 7.7%, respectively. 展开更多
关键词 Relative GPS positioning Residual effects Variance components Positional accuracy Sampling interval
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Evaluation of Third-Order Method for the Tests of Variance Component in Linear Mixed Models
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作者 Yanyan Wu Augustine Wong +1 位作者 Georges Monette Laurent Briollais 《Open Journal of Statistics》 2015年第4期233-244,共12页
Mixed models provide a wide range of applications including hierarchical modeling and longitudinal studies. The tests of variance component in mixed models have long been a methodological challenge because of its boun... Mixed models provide a wide range of applications including hierarchical modeling and longitudinal studies. The tests of variance component in mixed models have long been a methodological challenge because of its boundary conditions. It is well documented in literature that the traditional first-order methods: likelihood ratio statistic, Wald statistic and score statistic, provide an excessively conservative approximation to the null distribution. However, the magnitude of the conservativeness has not been thoroughly explored. In this paper, we propose a likelihood-based third-order method to the mixed models for testing the null hypothesis of zero and non-zero variance component. The proposed method dramatically improved the accuracy of the tests. Extensive simulations were carried out to demonstrate the accuracy of the proposed method in comparison with the standard first-order methods. The results show the conservativeness of the first order methods and the accuracy of the proposed method in approximating the p-values and confidence intervals even when the sample size is small. 展开更多
关键词 FAMILY Data GENETIC VARIANT LIKELIHOOD Ratio Test RANDOM effects THIRD-ORDER Method Variance component
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Study on the Lightning-radaited Electric Field Components at Mesospheric Altitudes
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作者 Fangrong ZHOU Yi MA +2 位作者 Hao PAN Bin ZOU Ye TIAN 《Meteorological and Environmental Research》 CAS 2021年第4期1-8,12,共9页
In this paper we have extended the semi-analytical model presented by Yashunin et al.to compute both of the lightning vertical and horizontal electric field considering the effect of nonlinear atmospheric electric par... In this paper we have extended the semi-analytical model presented by Yashunin et al.to compute both of the lightning vertical and horizontal electric field considering the effect of nonlinear atmospheric electric parameters,and validate its accuracy by using our 2-D FDTD method.It is noted that the semi-analytical model can predict not only the lightning vertical field,but also the horizontal electric field with a satisfied accuracy in a small region with a radius ranging from 5 to 30 km at a height from 80 to 90 km above the lightning strike point.Compared with the results in the free space with a vacuum,the conducting altitude atmosphere has a relatively little effect on the radiated field component,but it has much effect on the electrostatic and induction component because their duration times are longer than the local relaxation time.For example,the induction field component in the conducting nonlinear medium decreases by about 43%,compared with that in the free space with a vacuum.The induction field is larger than the radiation field component within a radius of 25 km at a height of 80 km above the lightning strike point.Therefore,although the induction component may be likely one extra energy source(except for the radiation field)for creating the pancake shape of some elves with a luminous central part,we have to take into account the effect of nonlinear atmospheric electric parameters on the prediction of induced field component peak value that is needed for the production of elves. 展开更多
关键词 Induction field component ELVES Semi-analytical model Nonlinear atmospheric electric parameters effect
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滁菊化学成分、药理作用及质量标志物预测分析
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作者 汪玉玲 吴晨曦 +1 位作者 徐心如 夏道宗 《中药新药与临床药理》 北大核心 2025年第2期307-316,共10页
滁菊是菊科多年生的草本植物,是“四大名菊”之一,以花序入药,含有黄酮类、挥发油、萜类、酚酸类、多糖类等成分,具有较高的药用和保健价值。该文在对滁菊化学成分、药理作用综述的基础上,围绕中药质量标志物的概念,从植物亲缘学和化学... 滁菊是菊科多年生的草本植物,是“四大名菊”之一,以花序入药,含有黄酮类、挥发油、萜类、酚酸类、多糖类等成分,具有较高的药用和保健价值。该文在对滁菊化学成分、药理作用综述的基础上,围绕中药质量标志物的概念,从植物亲缘学和化学成分特有性、传统药性、化学成分可测性、代谢组学和网络药理学、谱效关系、干燥方式等方面对滁菊的质量标志物进行预测分析,发现牛磺酸、谷氨酸、咖啡酰基奎宁酸、β-芹子烯、芹菜素等成分可作为滁菊质量标志物,以期为滁菊的质量评价研究提供依据。 展开更多
关键词 滁菊 化学成分 药理作用 质量标志物
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