期刊文献+
共找到14篇文章
< 1 >
每页显示 20 50 100
Maintaining the artemisinin content through direct and indirect in vitro regeneration and their assessment of variations with the field grown mother plants of Artemisia annua L.
1
作者 Shilpi PAUL Madan M GUPTA Suman P S KHANUJA 《Natural Products and Bioprospecting》 CAS 2012年第5期194-199,共6页
An efficient protocol for maintaining the artemisinin content in tissue culture and high frequency of in vitro direct and indirect regenerations of multiple shoots of high artemisinin yielding genotypes of Artemisia a... An efficient protocol for maintaining the artemisinin content in tissue culture and high frequency of in vitro direct and indirect regenerations of multiple shoots of high artemisinin yielding genotypes of Artemisia annua has been developed and their comparison with field grown mother plant has been carried out.The eleven elite genotypes(containing more than 1%artemisinin)were tested on seven different modified media formulations.Modified half MS(Murashige and Skoog’s)media containing 100 mg L^(-1) myo-inositol,0.5 g L^(-1) casine hydrolysate,5 mg L^(-1) biotin,2 mL L^(-1) RT(Revised Tobacco)vitamin stock,0.5 mg L^(-1) BAP and 0.01 mg L^(-1) NAA showed best regeneration while,above modified MS medium containing 0.2 mg L^(-1) BAP and 0.2 mg L^(-1) NAA showed maximum shoot multiplication with maintained artemisinin content.Based on the chemical profiles of both the systems,minor difference was observed in their artemisinin content.A large scale culture of these plants maintained the normal growth index along with the artemisinin content and could be a better alternative to maintain the high artemisinin yielding genotypes with their genetic constraint in specific media combinations and also used as base material for further genetic improvement. 展开更多
关键词 direct and indirect regeneration Artemisia annua ARTEMISININ BAP NAA
在线阅读 下载PDF
Comparison of direct and indirect determinations of dynamic ventilation rate in a modern dairy free stall barn
2
作者 Bing Zou Albert J.Heber +3 位作者 Zhengxiang Shi Songhuai Du Yaomin Jin Teng Teeh Lim 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2020年第6期41-46,共6页
Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air emissions.As direct air exc... Reliable estimation of the ventilation rate(VR)in intensive livestock buildings is necessary for studying building environmental control strategies and predicting indoor air quality and air emissions.As direct air exchange measurements are time-consuming and expensive,it is environmentally inefficient to measure livestock building VR continuously in practice.Hence,indirect VR estimation methods have been widely used in modelling environmental control and air emissions,and also to measure airflow in the field.The accuracy of indirect measurement methods needs to be evaluated by comparing with direct measurements.In this study,the direct and indirect methods of determining hourly and daily mean VRs were applied to a mechanically-ventilated dairy free stall barn monitored by the 24-month National Air Emissions Monitoring Study.The direct method was used to continuously monitor fan rotational speeds,and differential static pressures,coupled with periodic in-situ fan performance assessments,to calculate the VR.The indirect method consisted of estimating the VR using CO2 concentration measurements and the CO2 mass balance method.The average daily and hourly means(mean±SD)of directly measured barn ventilation rates for two years were(246±73)m3/s and(245±77)m3/s,respectively.The average daily and hourly means(mean±SD)of barn ventilation rates estimated by the CO2 mass balance method were(287±93.4)m3/s and(287±118)m3/s,respectively.Correlation analyses showed a strong correlation between the indirect CO2 mass balance method and direct measurement methods(r=0.93 for daily means and r=0.85 for hourly means). 展开更多
关键词 dynamic ventilation rate modern dairy free stall barn carbon dioxide mass balance dairy cow direct and indirect determination comparison
原文传递
语法专题课DIRECT SPEECH AND INDIRECT SPEECH
3
作者 汪颖 《初中生辅导》 2016年第30期15-23,共9页
关键词 直接引语 direct SPEECH and indirect SPEECH 专题课
原文传递
Chemical constituents, cytotoxic, antifungal and antimicrobial properties of Centaurea diluta Ait. subsp. algeriensis(Coss. & Dur.) Maire 被引量:4
4
作者 Hanene Zater Joelle Huet +4 位作者 Veronique Fontaine Samir Benayache Caroline Stevigny Pierre Duez Fadila Benayache 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2016年第6期537-543,共7页
Objective:To investigate the chemical composition of a moderately polar extract(CHC1_3 soluble part of the MeOH-H_2O extract) obtained from the aerial parts(leaves and flowers) of Centaurea diluta Ait.subsp.algeriensi... Objective:To investigate the chemical composition of a moderately polar extract(CHC1_3 soluble part of the MeOH-H_2O extract) obtained from the aerial parts(leaves and flowers) of Centaurea diluta Ait.subsp.algeriensis(Coss.& Dur.) Maire,a species endemic to Algeria and Morocco on which no reports are available to date.To evaluate in vitro the cytotoxic,antifungal and antimicrobial activities of this extract and the cytotoxic and antimicrobial activities of its isolated secondary metabolites.Methods:The cytotoxic effects of the extract were investigated on 3 human cancer cell lines i.e.the A549 non-small-cell lung carcinoma(NSCLC),the MCF7 breast adenocarcinoma and the U373 glioblastoma using a MTT colorimetric assay.Biological data allowed to guide the fractionation of the extract by separation and purification on silica gel 60(CC and TLC).The isolated compounds which were characterized by spectral analysis,mainly HR-ESIMS,HR-EIMS,UV and NMR experiments(~1H,^(13)C,COSY,ROESY,HSQC and HMBC) and comparison of their spectroscopic data with those reported in the literature,were evaluated for cytotoxic activities on six cancer cell lines(A549,MCF7,U373,Hs683 human glioma,PC3 human prostate and B16-F10 murine melanoma).The direct and indirect antibacterial and antifungal activities were determined using microdilution methods for the raw extract and TLC-bioautography and microdilution methods against standard and clinical strains for the isolated compounds.Results:The raw extract reduced cell viability with IC_(50)s of 27,25 and 21 μg/mL on A549,MCF7 and U373,respectively.Five secondary metabolites:two phenolic compounds(vanillin 1,paridol 3),a lignan[(-)-arctigenin 2]and two flavonoid aglycones(eupatilin 4 and jaceosidin 5),were then isolated from this extract.Moderate cytotoxic effects were observed for(-)-arctigenin 2(IC_(50)s:28 and 33μM on Hs683 and B16-F10,respectively),eupatilin 4(IC_(50)s:33 and 47 μM on B16-F10 and PC3,respectively) and jaceosidin 5(IC_(50)s:32 and 40 μM on PC3 and B16-F10,respectively).Conclusions:All the isolated compounds were described for the first time from this species.Although inactive against 7 tested microorganisms(fungi,bacteria and yeast,human or plant pathogens),the raw extract was able to potentiate the effect of beta-lactam antibiotics on methicillin-resistant Staphylococcus aureus(MRSA),reducing the minimal inhibitory concentrations(MICs) by a factor of 2-32-fold.No synergy was found between the extract and streptomycin.From the five isolated compounds only jaseosidin 5 showed a moderate antimicrobial activity. 展开更多
关键词 FLAVONOIDS Lignans Centaurea diluta Asteraceae Cytotoxic activity direct and indirect antimicrobial activity MRSA
暂未订购
Fast inactivation of microbes and degradation of organic compounds dissolved in water by thermal plasma 被引量:1
5
作者 Ahmed Rida GALALY Guido VAN OOST 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第8期82-88,共7页
The multifunctionality and the advantages of thermal plasma for the fast inactivation of viable cells and degradation of organic compounds dissolved in waste water are presented.A complete bacterial inactivation proce... The multifunctionality and the advantages of thermal plasma for the fast inactivation of viable cells and degradation of organic compounds dissolved in waste water are presented.A complete bacterial inactivation process was observed and studied using a thermal plasma treatment source with very short application times,in particular for Staphylococcus aureus bundle spore survival.The survival curves and analyses of the experimental data of the initial and final densities of S.aureus bacteria show a dramatic inhibitory effect of the plasma discharge on the residual bacteria survival ratio.As the exposure time increased,the inactivation process rate increased for direct exposure more than it did for indirect exposure.The evaluation of direct and indirect exposure was based on the analysis of the ultraviolet spectrum from the absorbance spectra of the organic compound dye called benzene sulfonate(C(16)H(11)N2Na O4S)and of viable cells called S.aureus.Organic compounds were degraded and viable cells were killed in a short time by thermal plasma.Moreover,analyses of total carbon,total organic carbon,and total inorganic carbon showed a fast decrease in organically bound carbon,however,this was not as fast as the absorbance spectra revealed by the exposure time increasing more for direct exposure than indirect exposure.After 100 s of exposure to the organic compound dye the removal had a maximun of 40%for samples with indirect exposure to the plasma and a maximum of 90%for samples with the direct exposure.For both samples,where some organic contaminants still remained in treated water,four electrolytes(KCl,Na Cl,Na2SO4,and CH3COONa)were added to be effective for complete sterilization,reaching a purity of 100%.A proposal is made for an optimized thermal plasma water purification system(TPWPS)to improve fast inactivation of microbes and the degradation of organic compounds dissolved in water(especially for direct exposure rather than indirect exposure)using a hybrid plasma torch with an electrical power of 125 kW(500 V–250 A)producing a high-temperature(10 000 K–19 000 K)plasma jet with a maximum gas consumption of 28 mg s^-1. 展开更多
关键词 water treatment thermal plasma direct and indirect exposure degradation of organic compounds inactivation of microbes
在线阅读 下载PDF
Different Performances of H_2O_2 to Oxidise Aldicarb and Hexazinone in the Advanced Oxidation Process of Ozone/Hydrogen Peroxide 被引量:1
6
作者 冉治霖 孙楚 +2 位作者 李绍峰 CRAIG Denver Williams TREVOR John Hocking 《Journal of Donghua University(English Edition)》 EI CAS 2014年第3期348-353,共6页
The degradations of hexazinone and aldicarb by direct ozonation combined an advanced oxidation process( AOP) of O3/H2O2 were investigated in this study focusing on the oxidation mechanism by identifying the hydrogen p... The degradations of hexazinone and aldicarb by direct ozonation combined an advanced oxidation process( AOP) of O3/H2O2 were investigated in this study focusing on the oxidation mechanism by identifying the hydrogen peroxide consumption during the oxidation process of the two chemicals. The results showed that H2O2 could enhance the removal rate of the triazine herbicide hexazinone,and it was consumed along with the variation of removal rate in the light of different pH levels. The addition of H2O2 contributed little to the removal of the thiocarbamate herbicide aldicarb and H2O2 content kept constantly throughout the degradation process. Tert-butyl alcohol( TBA) effectively scavenged the ·OH radical for hexazinone,but had no effect on the removal rate of aldicarb. Aldicarb removal was mainly attributed to direct ozonation molecule in both O3( 97.00%) and O3/H2O2( 96.76%)systems. Moreover,sole O3 could hardly oxidize hexazinone whereas·OH radicals contribute respective 74.70% and 97.50% of removal in O3 system and O3/H2O2 AOP. All of these findings suggest that the mechanism of ·OH radical generation and the chain reaction in O3/H2O2 AOP should be further discussed. 展开更多
关键词 HEXAZINONE ALDICARB O3/H2O2 direct and indirect oxidation H2O2consumption
在线阅读 下载PDF
Shear wave velocity prediction:A review of recent progress and future opportunities
7
作者 John Oluwadamilola Olutoki Jian-guo Zhao +5 位作者 Numair Ahmed Siddiqui Mohamed Elsaadany AKM Eahsanul Haque Oluwaseun Daniel Akinyemi Amany H.Said Zhaoyang Zhao 《Energy Geoscience》 EI 2024年第4期36-54,共19页
Shear logs,also known as shear velocity logs,are used for various types of seismic analysis,such as determining the relationship between amplitude variation with offset(AVO)and interpreting multiple types of seismic d... Shear logs,also known as shear velocity logs,are used for various types of seismic analysis,such as determining the relationship between amplitude variation with offset(AVO)and interpreting multiple types of seismic data.This log is an important tool for analyzing the properties of rocks and interpreting seismic data to identify potential areas of oil and gas reserves.However,these logs are often not collected due to cost constraints or poor borehole conditions possibly leading to poor data quality,though there are various approaches in practice for estimating shear wave velocity.In this study,a detailed review of the recent advances in the various techniques used to measure shear wave(S-wave)velocity is carried out.These techniques include direct and indirect measurement,determination of empirical relationships between S-wave velocity and other parameters,machine learning,and rock physics models.Therefore,this study creates a collection of employed techniques,enhancing the existing knowledge of this significant topic and offering a progressive approach for practical implementation in the field. 展开更多
关键词 Shear wave(S-wave)velocity direct and indirect measurement Empirical relationship Artificial intelligence(AI) Machine learning Rock physics model
在线阅读 下载PDF
Overview of Standardized Testing System for ESL Students in U.S. Kindergarten Thru Grade 12 Public Schools
8
作者 Volkan Cicek 《Sino-US English Teaching》 2011年第12期773-786,共14页
A comprehensive overview of standardized testing system for ESL (English as a Second Language) students in U.S kindergarten thru grade 12 public school system is reviewed within the context of basis on federal and s... A comprehensive overview of standardized testing system for ESL (English as a Second Language) students in U.S kindergarten thru grade 12 public school system is reviewed within the context of basis on federal and state laws, as well as instructional basis. Identification process of LEP (Limited English Proficient) students via nomination, testing and testing criteria to be identified as LEP, hence ESL if placed in the program is defined in detail Standardized testing process of these students based on the federal AYP (Adequate Yearly Progress) measures through regular state standardized tests depending on three types of instructional program that LEP student is placed in the school that are Bilingual Education Program, ESL Program, and Two-Way Immersion Dual Language Programs are described. Standardized testing process of these students based on the federal AYP measures through other means if exempted from regular state standardized tests such as LAT (Linguistically Accommodated Testing) and the conditions to be exempted are discussed in detail. Holistically rated English Language Proficiency Assessments that are implemented to fulfill federal AMAOs (Annual Measurable Achievement Objectives) measures are defined briefly. Physical features of LAT test as well as direct and indirect accommodations for LAT reading, mathematics and science tests are defined via the accommodation needed and the type of assistance provided. Lastly, testing criteria to exit LEP status and other issues concerning exiting LEP status are reviewed 展开更多
关键词 ESL (English as a Second Language) bilingual education LEP (Limited English Proficient) LanguageProficiency Assessment linguistics accommodations direct and indirect accommodations standardized testing
在线阅读 下载PDF
Economic burden of irritable bowel syndrome in China 被引量:46
9
作者 Fang Zhang Wei Xiang +1 位作者 Chun-yan Li Shu-Chuen Li 《World Journal of Gastroenterology》 SCIE CAS 2016年第47期10450-10460,共11页
AIM To estimate annual direct and indirect costs for patients diagnosed with irritable bowel syndrome(IBS) and subtypes.METHODS Patients completed a standardized questionnaire concerning usage of healthcare resources,... AIM To estimate annual direct and indirect costs for patients diagnosed with irritable bowel syndrome(IBS) and subtypes.METHODS Patients completed a standardized questionnaire concerning usage of healthcare resources, travel costs, meals, and productivity loss of patients when seeking treatment for IBS. Total annual costs per patient were calculated as the sum of direct(including medical and nonmedical) and indirect costs. Total annual costs per patient among various IBS subtypes were compared. Analysis of variance and bootstrapped independent sample t-tests were performed to determine differences between groups after controlling for IBS subtypes.RESULTS A total of 105 IBS patients(64.80% female), mean age of 57.12 years ± 10.31 years), mean disease duration of 4.31 years ± 5.40 years, were included. Total annual costs per patient were estimated as CNy18262.84(USD2933.08). Inpatient and outpatient healthcare use were major cost drivers, accounting for 46.41%and 23.36% of total annual costs, respectively. Productivity loss accounted for 25.32% of total annual costs. The proportions of direct and indirect costs were similarto published studies in other countries. Nationally, the total costs of managing IBS would amount to CNy123.83 billion(USD1.99 billion). Among the IBS subtypes, total annual costs per patient of IBS-M was highest at CNy18891.18(USD3034). Furthermore, there was significant difference in productivity loss among IBS subtypes(P = 0.031).CONCLUSION IBS imposes a huge economic burden on patients and healthcare systems, which could account for 3.3% of the total healthcare budget for the entire Chinese nation. More than two-thirds of total annual costs of IBS consist of inpatient and outpatient healthcare use. Among the subtypes, IBS-M patients appear to have the greatest economic burden but require further confirmation. 展开更多
关键词 Irritable bowel syndrome Burden of illness direct and indirect medical and nonmedical costs Irritable bowel syndrome subtype Productivity loss
暂未订购
Exciton optical absorption in asymmetric ZnO/ZnMgO double quantum wells with mixed phases 被引量:4
10
作者 Zhi-Qiang Han Li-Ying Song +1 位作者 Yu-Hai Zan Shi-Liang Ban 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第7期456-463,共8页
The optical absorption of exciton interstate transition in Zn1-xlMgxlO/ZnO/Zn1-xcMgxcO/ZnO/Zn1-xrMgxrO asymmetric double quantum wells(ADQWs)with mixed phases of zinc-blende and wurtzite in Zn1-xMgxO for 0.37<x<... The optical absorption of exciton interstate transition in Zn1-xlMgxlO/ZnO/Zn1-xcMgxcO/ZnO/Zn1-xrMgxrO asymmetric double quantum wells(ADQWs)with mixed phases of zinc-blende and wurtzite in Zn1-xMgxO for 0.37<x<0.62 is discussed.The mixed phases are taken into account by our weight model of fitting.The states of excitons are obtained by a finite difference method and a variational procedure in consideration of built-in electric fields(BEFs)and the Hartree potential.The optical absorption coefficients(OACs)of exciton interstate transition are obtained by the density matrix method.The results show that Hartree potential bends the conduction and valence bands,whereas a BEF tilts the bands and the combined effect enforces electrons and holes to approach the opposite interfaces to decrease the Coulomb interaction effects between electrons and holes.Furthermore,the OACs indicate a transformation between direct and indirect excitons in zinc-blende ADQWs due to the quantum confinement effects.There are two kinds of peaks corresponding to wurtzite and zinc-blende structures respectively,and the OACs merge together under some special conditions.The computed result of exciton interband emission energy agrees well with a previous experiment.Our conclusions are helpful for further relative theoretical studies,experiments,and design of devices consisting of these quantum well structures. 展开更多
关键词 quantum well mixed phase exciton transition direct and indirect exciton optical absorption
原文传递
The Secondary Motor Cortex-striatum Circuit Contributes to Suppressing Inappropriate Responses in Perceptual Decision Behavior
11
作者 Jing Liu Dechen Liu +4 位作者 Xiaotian Pu Kexin Zou Taorong Xie Yaping Li Haishan Yao 《Neuroscience Bulletin》 SCIE CAS CSCD 2023年第10期1544-1560,共17页
The secondary motor cortex(M2)encodes choice-related information and plays an important role in cue-guided actions.M2 neurons innervate the dorsal striatum(DS),which also contributes to decision-making behavior,yet ho... The secondary motor cortex(M2)encodes choice-related information and plays an important role in cue-guided actions.M2 neurons innervate the dorsal striatum(DS),which also contributes to decision-making behavior,yet how M2 modulates signals in the DS to influence perceptual decision-making is unclear.Using mice performing a visual Go/No-Go task,we showed that inactivating M2 projections to the DS impaired performance by increasing the false alarm(FA)rate to the reward-irrelevant No-Go stimulus.The choice signal of M2 neurons correlated with behavioral performance,and the inactivation of M2 neurons projecting to the DS reduced the choice signal in the DS.By measuring and manipulating the responses of direct or indirect pathway striatal neurons defined by M2 inputs,we found that the indirect pathway neurons exhibited a shorter response latency to the No-Go stimulus,and inactivating their early responses increased the FA rate.These results demonstrate that the M2-to-DS pathway is crucial for suppressing inappropriate responses in perceptual decision behavior. 展开更多
关键词 Secondary motor cortex STRIATUM Visual perceptual decision Choice signal direct and indirect pathway striatal neurons
原文传递
International VAT Fraud: The Carousel Game
12
作者 Silvia Fedeli Francesco Forte 《Journal of Modern Accounting and Auditing》 2011年第3期211-226,共16页
The EU market's free circulation principle severs the VAT chain at the EU States' borders, thus, encouraging VAT fraud. The increased "transit traffic" from outside the EU with final destination in EU countries al... The EU market's free circulation principle severs the VAT chain at the EU States' borders, thus, encouraging VAT fraud. The increased "transit traffic" from outside the EU with final destination in EU countries also contributes to VAT fraud. To examine this issue, we model some different collusive features of these frauds, on which basis we explore their effects on the international trade and the domestic market. 展开更多
关键词 European Union value added tax direct and indirect tax evasion VAT carousel Nash equilibrium fraud-chain
在线阅读 下载PDF
Large manipulative experiments reveal complex effects of food supplementation on population dynamics of Brandt's voles 被引量:5
13
作者 Baofa Yin Guoliang Li +3 位作者 Xinrong Wan Guozhen Shang Wanhong Wei Zhibin Zhang 《Science China(Life Sciences)》 SCIE CAS CSCD 2017年第8期911-920,共10页
Although food supplementation is well known to increase population density,there is still debate on the causative effects of food supplementation on reproduction,survival,and immigration.Large manipulative experiments... Although food supplementation is well known to increase population density,there is still debate on the causative effects of food supplementation on reproduction,survival,and immigration.Large manipulative experiments,which exclude any confounding effects of dispersal and predation,are essential for clarifying the debate.In this study,we investigated the effects of food supplementation on Brandt's vole population dynamics and plant community in eight large enclosures(0.48 ha each) from2010 to 2014.Food supplementation showed significant positive effects on population density due to increases in recruitment;however,it showed a complex effect on survival of voles:positive in non-breeding seasons,but negative in breeding seasons.In addition,food supplementation increased the quality of plants(as reflected by increased crude protein content),but decreased the quantity of less preferred plants in experimental enclosures.Thus,food seems to have direct positive effects on small rodents through improvement of food supply and indirect negative effects through food-induced density-dependent effects,and may have long-term effects on rodents through altering plant community composition and abundance. 展开更多
关键词 demographic parameters direct and indirect effects food quantity and quality food supplementation plant communitycomposition population dynamics RECRUITMENT SURVIVAL VOLES
原文传递
Effects of elevated temperature on chemistry of an invasive plant,its native congener and their herbivores 被引量:6
14
作者 Zhen Liu Hongwei Yu +1 位作者 Xiao Sun Jianqing Ding 《Journal of Plant Ecology》 SCIE CSCD 2022年第3期450-460,共11页
Climatic warming affects plant growth and physiology,yet how warming alters chemistry in invasive plants and indirectly affects herbivorous insects remains largely unknown.Here,we explored warming-induced changes in l... Climatic warming affects plant growth and physiology,yet how warming alters chemistry in invasive plants and indirectly affects herbivorous insects remains largely unknown.Here,we explored warming-induced changes in leaf chemistry of the invasive plant Alternanthera philoxeroides and its native congener Alternanthera sessilis,and further examined how these changes affected the performance of the herbivores,Cassida piperata and Spodoptera litura.We conducted a simulated warming experiment to address its effects on 13 leaf chemical traits of A.philoxeroides and A.sessilis.We measured growth and development time of two herbivores reared on plants from warming or ambient controls.Warming significantly affected leaf chemistry composition for both the invasive and native Alternanthera.Warming decreased nitrogen concentration in A.philoxeroides and increased total flavonoid and total phenol concentration in A.sessilis.The effects of warming on nutrients(i.e.fructose,sucrose,total soluble sugar and starch)varied with individual chemicals and plant species.Weight of C.piperata pupal and S.litura larval reared on warming-treated A.sessilis significantly decreased compared with non-warmed control,and a similar pattern was observed for weight of S.litura larval feeding on warming-treated A.philoxeroides.In addition,warming-treated A.sessilis significantly prolonged larval development time of S.litura.These results indicate that warming can directly affect the leaf chemistry in both invasive plant and its native congener,but these effects vary by species.Such differences in warming-induced changes in plant chemistry could indirectly affect herbivorous insects associated with the invasive and native plants. 展开更多
关键词 climate warming direct and indirect effects invasive plant HERBIVORE secondary chemicals
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部