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Chemical composition of essential oils and in vitro antioxidant activity of fresh and dry leaves crude extracts of medicinal plant of Lactuca Sativa L.native to sultanate of Oman

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Asian Pacific Journal of Tropical Biomedicine 2013年第5期3卷 353-357页

作者： Rahma Said Salim Al Nomaani Mohammad Amzad Hossain Afaf Mohammed Weli Qasim Al-Riyami Jamal Nasser Al-Sabahi School of Pharmacy College of Pharmacy and NursingUniversity of Nizwa Central Instrument Laboratory College of Agriculture and Marine SciencesSultan Qaboos University

Objective:To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L.(L.sativa).Methods:The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L.sativa(lettuce)grown in Sultanate of Oman by hydro distillation method.The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity(DPPH)method.Results:About 20 chemical compounds of different concentration representing 83.07%and 79.88%respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves asα-pinene(5.11%and 4.05%).γ-cymene(2.07%and 1.92%),thymol(11.55%and 10.73%),durenol(52.00%and 49.79%),α-terpinene(1.66%and 1.34%),thymol acetate(0.99%and 0.67%),caryophyllene(2.11%and 1.98%),spathulenol(3.09%and 2.98%).camphene(4.11%and3.65%),limonene(1.28%and 1.11%)representing these major chemical compounds.However,some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including p-pinene,α-terpinolene,linalool,4-terpineol,α-terpineol,o-methylthymol,L-alloaromadendrene and viridiflorene.Conclusions:The chemical consliluents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes,sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons.Therefore,the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant,antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.

关键词： Lactuca saliva Omani lettuce Clevenger apparatus Essential oil Durenol Thymol Soxhlet extractor Organic crude extracts Antioxidant activity GC-MS analyses

Geomagnetic Secular Variations and Climatic Changes Since 15,000 a B.P.,Beijing Region

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Science China Chemistry 1994年第8期37卷 984-990页

作者：朱日祥顾兆炎黄宝春金增信魏新富李春景 Institute of Geophysics Academia SinicaBeijing 100101PRC Institute of Geology Academia SinicaBeijing 100029

A sediment sequence,from Fangshan in the Beijing Basin,has been sampled for paleomag-netic studies.The 1430 paleomagnetic samples possess a strong and stable magnetic remanence.A high-res-olution record of secular variation in North China over the past 15 ka B.P.has been provided.Spectral anal-yses have shown that main periods of inclination,declination and relative intensity are about 1000,2000 and4000 a;800,1640 and 3300 a;and 820,1200,2200 and 3300 a;respectively.Two excursions have beendiscovered,and the correlation between the geomagnetic intensity variations and the climatic changes hasbeen discussed.

关键词： geomagnetic secular variation spectral analyses Paleoclimate the Late Pleistocene peat Fangshan

STUDY ON CARGO FLOW PROJECTION IN TUMEN RIVER ECONOMIC DEVELOPMENT AREA

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Chinese Geographical Science 1999年第1期9卷 70-77页

作者：王荣成叶宝明 Department of Geography Northeast Normal University Changchun P. R. China

The paper studies the methodologies of the cargo flow study and projections in Tumen River Economic Development Area(TREDA) that some governments and international scholars used. The authors consider that, in order topromote investment, facilitation of cross-border trade and infrastructure in the region, the basic methodology should bebased on the regional economic growth of pertinent Northeast Asian countries and regions to make projections of the situations of regional cargo flows, and then analyzing the cargo flow trend. Based on the above, the authors utilize the routescomparing model and gravity model to forecast the cargo flows through the ports and related routes in TREDA (2000 -2020). The authors also inquire into the main obstacles which affect the cargo flows of the region, analyze the influenceson cargo flows if the obstacles change with sensitivity analyses and try to find the way to sole the obstacles.

关键词： cargo flow projection routes comparison model gravity model sensitivity analyses

Control of human filarial vector,Culex quinquefasciatus Say 1823(Diptera:Culicidae)through bioactive fraction of Cayratia trifolia leaf

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Asian Pacific Journal of Tropical Biomedicine 2013年第12期3卷 980-984页

作者： Sumanta Chakraborty Someshwar Singha Kuntal Bhattacharya Goutam Chandra Mosquito and Microbiology Research Units Parasitology LaboratoryDepartment of ZoologyThe University of Burdwan

Objective:To investigate the mosquito larvicidal activity of Cayratia trifolia(L.)Domin(Vitaceae:Vitales)(C.trifolia)which is distributed in many parts of India with medicinal properties as vector control is facing threat due to the emergence of resistance to synthetic insecticides.Methods:Young and mature leaves of C.trifolia were investigated for larvicidal activity against3rd instars larvae of Culex quinquefasciatus in different seasons throughout the year.The active fractions were extracted using six different solvents in a non-polar to polar fashion viz petroleumether,benzene,chloroform:methanol(1:1 v/v),acetone,absolute alcohol and distilled water.Dose dependent mortality was recorded against each solvent extract.Determination of LD_(50)and LD_(90)were executed through log-probit analysis using the most bioactive fraction.The fluctuations in mortality were statistically co-related through ANOVA analyses concerning different seasons and types of leaves as random variables.Justification of larvicidal activity was established through student's t-test.Costing effects were evaluated on the non-target water fauna under laboratory conditions.Thin layer chromatographic techniques were performed for phytochemical analysis and categorization of chemical personality of the active fractions using the most effective solvent extract following standard methods.Results:Significant variations in mortality rate were noted with respect to the type of leaves(mature and senescence),concentration of leaf extract and between seasons.The water extract among all the solvent extracts was found to induce cent percent mortality at 50 mg/L in test mosquito species within 24 h with a LD_(50)and LD_(90)value of 10.70 mg/L and 27.64 mg/L respectively.No significant mortality was recorded in non-target water population.Chromatographic analyses of the water extract revealed the presence of steroids,triterpene glycosides,essential oil,phenolics and diterpenes as secondary phytochemicals.Conclusions:Water extract of C.trifolia leaf promised a

关键词： Cayratia trifolia Culex quinquefasciatus Larvicidal Phytochemical analyses

Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

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Asian Pacific Journal of Tropical Biomedicine 2013年第1期3卷 69-73页

作者： Laila Salim Al Hashmi Mohammad Amzad Hossain Afaf Mohammed Weli Qasim Al-Riyami Jamal Nasser Al-Sabahi School of Pharmacy College of Pharmacy and NursingUniversity of NizwaP.0.Box 33Postal Code 616NizwaSultanate of Oman Central Instrument Laboratory College of Agriculture and Marine SciencesSultan Qaboos UniversitySultanate of Oman

Objective:To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L(T.vulgaris)by gas chromatography-mass spectrometry(GC-MS).Methods:The shade dried leaves powder was extracted with methanol by using Soxhlet extractor.Methanol crude extracts of T.vulgaris and the derived fractions of hexane,chloroform,ethyl acetate and butanol were obtained.Results:Qualitative analyses of various organic crude extracts of T.vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds.Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important.Further,the T.vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation.The crude extracts were prepared from the powder leaves of T.vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis.Conclusions:All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T.vulgaris are biologically active molecules.Thus the identification of a good number of compounds in various crude extracts of T.vulgaris might have some ecological role.

关键词： Thymus vulgaris L Preparation crude extracts Soxhlet extractor GC-MS analyses

Acute gastroenteritis outbreak caused by a GII.6 norovirus

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World Journal of Gastroenterology 2015年第17期21卷 5295-5302页

作者： Ling-Fei Luo Kun Qiao Xiao-Guang Wang Ke-Ying Ding Hua-Ling Su Cui-Zhen Li Hong-Jing Yan The Center for Disease Control and Prevention of Minghang District Minghang District

AIM:To report an acute gastroenteritis outbreak caused by a genogroup 2 genotype 6(GII.6) strain norovirus in Shanghai,China.METHODS:Noroviruses are responsible for approximately half of all reported gastroenteritis outbreaks in many countries.Genogroup 2 genotype 4 strains are the most prevalent.Rare outbreaks caused by GII.6 strains have been reported.An acute gastroenteritis outbreak occurred in an elementary school in Shanghai in December of 2013.Field and molecular epidemiologic investigations were conducted.RESULTS:The outbreak was limited to one class in an elementary school located in southwest Shanghai.The age of the students ranged from 9 to 10 years.The first case emerged on December 10,2013,and the last case emerged on December 14,2013.The cases peaked on December 11,2013,with 21 new cases.Of 45 students in the class,32 were affected.The main symptom was gastroenteritis,and 15.6%(5/32) of the cases exhibited a fever.A field epidemiologic investigation showed the pathogen may have been transmitted to the elementary school from employees in a delicatessen via the first case student,who had eaten food from the delicatessen one day before the gastroenteritis episodes began.A molecular epidemiologic investigation identified the cause of the gastroenteritis as norovirus strain GII.6;the viral sequence of the student cases showed 100% homology with that of the shop employees.Genetic relatedness analyses showed that the new viral strain is closely related to previously reported GII.6 sequences,especially to a strain reported in Japan.CONCLUSION:This is the first report to show that norovirus strain GII.6 can cause a gastroenteritis outbreak.Thus,the prevalence of GII.6 noroviruses requires attention.

关键词： Genogroup 2 genotype 6 genogroup Genetic relatedness analyses Gastroenteritis Noroviruses Outbreak

Development of the HL-2M digital pulse analysis system

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Plasma Science and Technology 2019年第11期21卷 93-98页

作者：潘银海郑博文张伟阴泽杰 State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026People’s Republic of China Department of Modern Physics University of Science and Technology of ChinaHefei 230026People’s Republic of China

A digital pulse analysis system is an important diagnostic system in nuclear physics experimental research.In response to the demand for reflecting the particle state in a nuclear physics experiment,we have designed and developed a real-time digital pulse analysis system and applied it to the digital nuclear pulse waveform discrimination of different detectors in the HL-2M tokamak.The system is based on the peripheral component interconnect extensions for instrumentation(PXI)platform,while its software was written in LABVIEW.The key technologies involved in the system implementation include digital pulse analysis technology,digital discrimination technology,pulse height analysis technology,etc.The system has been applied to the plastic scintillator detector at the Neutron Source Lab of the University of Science and Technology of China.And the experimental results indicate that the system can discriminate between neutron(n)particles and gamma(γ)particles well when used to measure the plastic scintillator detector.

关键词： digital pulse analysis plastic scintillator detector discrimination height analyses

Portable fiber-optic laser-induced breakdown spectroscopy system for the quantitative analysis of minor elements in steel

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Plasma Science and Technology 2019年第3期21卷 46-51页

作者：曾庆栋邓凡朱志恒唐云王波云肖永军熊良斌余华清郭连波李祥友 School of Physics and Electronic-information Engineering Hubei Engineering University Wuhan National Laboratory for Optoelectronics (WNLO) Huazhong University of Science and Technology Wuhan National Laboratory for Optoelectronics (WNLO) Huazhong University of Science andTechnology

In this paper, we developed a portable laser-induced breakdown spectroscopy(LIBS) using an optical fiber to deliver laser energy and used it to quantitatively analyze minor elements in steel.The R^2 factors of calibration curves of elements Mn, Ti, V, and Cr in pig iron were 0.9965,0.9983, 0.9963, and 0.991, respectively, and their root mean square errors of cross-validation were 0.0501, 0.0054, 0.0205, and 0.0245 wt%, respectively. Six test samples were used for the validation of the performance of the calibration curves established by the portable LIBS. The average relative errors of elements Mn, Ti, V, and Cr were 2.5%, 11.7%, 13.0%, and 5.6%,respectively. These results were comparable with most results reported in traditional LIBS in steel or other matrices. However, the portable LIBS is flexible, compact, and robust, providing a promising prospect in industrial application.

关键词： laser-induced breakdown spectroscopy optical fiber quantitative analyses minor element

THE FIRST INTERNATIONAL WORKSHOP ON SATELLITE ANALYSIS OF TROPICAL CYCLONES:SUMMARY OF CURRENT OPERATIONAL METHODS TO ESTIMATE INTENSITY

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Tropical Cyclone Research and Review 2012年第4期1卷 469-481页

作者： CHRISTOPHER VELDEN REW BURTON KOJI KUROIWA Cooperative Institute for Meteorological Satellite Studies University of WisconsinMadisonWisconsinU.S.A. Australian Bureau of Meteorology PerthWestern AustraliaAustralia World Meteorological Organization GenevaSwitzerland

This paper summarizes the results and findings from the first International Workshop on Satellite analyses of Tropical Cyclones(IWSATC).Estimating tropical cyclone intensity in the absence of penetrating reconnaissance aircraft is mainly left to satellite-based remote sensing methods.The primary method used globally since the latter part of the last century is the Dvorak Technique.While this method has withstood the test of time,it is not without limitations,and has been subject to regional modifications by various national tropical cyclone analysis centers.Differences between agencies in both the application of the Dvorak Technique and in general operational procedures to derive final intensity estimates can lead to real-time warning conflicts,as well as issues with final best track values for climatological analyses.As coastal populations increase,the WMO recognizes these issues as potentially serious problems,and organized a workshop in 2011 to bring together tropical cyclone experts to 1) discuss current operational analysis practices,2) learn about developing satellite techniques,and 3) come up with a set of recommendations to start down a path towards a global congruence on intensity estimation procedures.

关键词： International Workshop on Satellite analyses of Tropical Cyclones paper summarizes satellite-based remote sensing methods