检索结果-南通市图书馆

A Comparative Investigation of the Biodegradation Behaviour of Linseed Oil-Based Cross-Linked Composites Filled with Industrial Waste Materials in Two Different Soils

引用

Journal of Renewable Materials 2023年第3期11卷 1254-1268页

作者： Eglė Malachovskienė Danguolė Bridžiuvienė jolita ostrauskaitė Justina Vaičekauskaitė Gailė Žalūdienė Biodeterioration Research Laboratory Nature Research CentreVilniusLT-08412Lithuania Department of Polymer Chemistry and Technology Kaunas University of TechnologyKaunasLT-50254Lithuania Laboratory of Bedrock Geology Nature Research CentreVilniusLT-08412Lithuania

The biodegradation of polymeric biocomposites formed from epoxidized linseed oil and various types of fillers(pine needles,pine bark,grain mill waste,rapeseed cake)and a control sample without filler was studied during 180 days of exposure to two types of forest soil:deciduous and *** weight loss,morphological,and structural changes of polymer composites were noticed after 180 days of the soil burial *** greatest weight loss of all tested samples was observed in coniferous forest soil(41.8%–63.2%),while in deciduous forest soil,it ranged between 37.7%and 42.3%.The most significant changes in the intensities of the signals evaluated by attenuated total reflectance infrared spectroscopy,as well as morphological changes determined by scanning electron microscopy,were assessed for polymer composite with rapeseed cake and specimen without filler in coniferous forest soil and are in a good agreement with weight loss *** significantly lower changes in weight loss,morphology,and structure of polymeric film with pine bark were noticed in both *** was suggested that fungi of Trichoderma,Penicillium,Talaromyces and Clonostachys genera are the possible soil microorganisms that degrade linseed oil-based cross-linked polymer ***,the novel polymer composites have the potential to be an environmentally friendly alternative to petroleum-based mulching films.

关键词： Polymer composites linseed oil industrial waste materials biodegradation soil burial

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pseudohypericin and Hyperforin in Hypericum perforatum from Northern Turkey:Variation among Populations,Plant Parts and Phenological Stages

引用

Journal of Integrative Plant Biology 2008年第5期50卷 575-580页

作者： Cüneyt irak jolita Radusiene Valdimaras Janulis Liudas Ivanauskas Faculty of Agriculture Department of Agronomy University of Ondokuz Mayis55139 KurupelitSamsunTurkey Institute of Botany VilniusLT-08406Lithuania Kaunas University of Medicine KaunasLT-44307Lithuania

Hypericum perforatum is a perennial medicinal plant known as ＂St. John＇s wort＂ in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolite concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages： vegetative, floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight （DW） for pseudohypericin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain increased concentrations of these secondary metabolites.

关键词： hyperforin Hypericum perforatum morphologic and phenologic variations population variability pseudohypericin.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Attention-Based and Time Series Models for Short-Term Forecasting of COVID-19 Spread

引用

Computers, Materials & Continua 2022年第1期70卷 695-714页

作者： Jurgita Markeviciute jolita Bernataviciene Ruta Levuliene Viktor Medvedev Povilas Treigys Julius Venskus Institute of Applied Mathematics Vilnius UniversityVilnius03225Lithuania Institute of Data Science and Digital Technologies Vilnius UniversityVilnius08412Lithuania

The growing number of COVID-19 cases puts pressure on healthcare services and public institutions *** pandemic has brought much uncertainty to the global economy and the situation in *** methods and modeling techniques are important tools for governments to manage critical situations caused by pandemics,which have negative impact on public *** main purpose of this study is to obtain short-term forecasts of disease epidemiology that could be useful for policymakers and public institutions to make necessary short-term *** evaluate the effectiveness of the proposed attention-based method combining certain data mining algorithms and the classical ARIMA model for short-term forecasts,data on the spread of the COVID-19 virus in Lithuania is used,the forecasts of epidemic dynamics were examined,and the results were presented in the ***,the approach presented might be applied to any country and other pandemic *** COVID-19 outbreak started at different times in different countries,hence some countries have a longer history of the disease with more historical data than *** paper proposes a novel approach to data registration and machine learning-based analysis using data from attention-based countries for forecast validation to predict trends of the spread of COVID-19 and assess risks.

关键词： COVID-19 spread modeling attention-based forecasting machine learning data registration data analysis ARIMA

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Variation of Bioactive Compounds in Hypericum perforatum Growing in Turkey During Its Phenological Cycle

引用

Journal of Integrative Plant Biology 2007年第5期49卷 615-620页

作者： Cüneyt Cirak jolita Radusiěne Birsen (Saglam) Karabük Valdimaras Janulis Liudas Ivanauskas Faculty of Agriculture Department of Agronomy University of Ondokuz Mayis Samsun 55139 Turkey Institute of Botany Zaliuju ezeru Vilnius LT-08406 Lithuania Kaunas University of Medicine Kaunas LT-44307 Lithuania

The present study was conducted to determine phenologic and morphogeneUc variation of hyperlcln, chlorogenlc acid and flavonoids, as rutin, hyperoside, apigenin-7-O-glucoside, quercitrin, quercetin content of Hypericum perforatum L. growing in Turkey. Wild growing plants were harvested at vegetative, floral budding, full flowering, fresh frulUng and mature fruiting stages and dissected into stem, leaf and reproductive tissues and assayed for bioacUve compounds by the High performance liquid chromatography （HPLC） method. Hypericin concentration ranged between 0 and 2.73 mg/g DW, chlorogenic acid 0.00-3.64 mg/g DW, rutin 0.00-3.36 mg/g DW, hyperoside 0.04- 22.42 mg/g DW, quercitrin 0.03-3.46 mg/g DW and quercetin 0.04-1.02 mg/g DW depending on ontogenetic and morphogenetic sampling. Leaves were found to be superior to stems and reproductive parts with regard to phenolic accumulation for all compounds tested while flowers accumulated the highest levels of hypericln. Quercltrln, quercetln and hypericin content in all tissues increased with advancing of developmental stages and reached their highest level during flower ontogenesis. Similarly, chlorogenic acid, hyperoside and apigenin-7-O-glucoside content in different plant parts increased during plant development, however, the highest level was observed at different stages of plant phenology for each tissue. Chlorogenic acid was not detected in stems, leaves and reproductive parts in several stages of plant phenology and its variation during plant growth showed inconsistent manner. In contrast to the other compounds examined, rutin content of stems and leaves decreased with advanc- ing of plant development and the highest level for both tissues was observed at the vegetative stage. However, content of the same compound in reproductive parts was the highest at mature fruiting. The present findings might be useful to obtain increased concentration of these natural compounds.

关键词： chiorogenic acid flavonoids hypericin Hypericum perforatum morphogenetic variation phenologic variation.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Is Postpartum Uterine Involution Impacted by Instrumental or Operative Procedures? Ultrasound Study

引用

Open Journal of Obstetrics and Gynecology 2018年第13期8卷 1289-1304页

作者： Virginija Paliulyte Grazina Stanislava Drasutiene Diana Ramasauskaite Daiva Bartkeviciene jolita Zakareviciene Juozas Kurmanavicius Clinic of Obstetrics and Gynecology of Vilnius University Vilnius Lithuania Centre of Obstetrics and Gynecology Vilnius University Hospital Santaros Klinikos Vilnius Lithuania Department of Obstetrics University Hospital Zurich Zurich Switzerland

Objectives: Practitioners are continuously concerned with the differences between the normal puerperium and the uterine involution after operated deliveries. This prospective observational study pays attention to the uterine involution period after the instrumental or operative delivery and compares the results with those observed in uncomplicated labour. Methods: Over two postpartum months 66 women after normal (48) and complicated (18) labour were examined for repeated uterine parameters. The analysis was performed using SPSS version 21. Results: There was no statistically significant difference between the median uterine size parameters or the uterine artery indices after the normal delivery and instrumental/operative uterine manipulations during the involution period, except for a faster declining trend observed in anteroposterior diameter within the first month after normal labour. The diastolic notch was more frequent in early puerperium after complicated labor, but less frequent later. The diastolic notch did not appear in all the postpartum women even two months after labour. There was evidence of more frequent gas detected in the pathological rather than in the physiological group. Conclusion: Postpartum uterine involution is not impacted by instrumental or operative procedures. After complicated labour gas appearance is more common, but it does not necessarily indicate the presence of endometritis or retained placental tissues.

关键词： Postpartum Ultrasound Uterus Physiology Pathology Cesarean Scar

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：