•Pressurized limonene extracts favourably lipids from microalgae.•Medium polarity lipids and valuable fatty acids have been extracted.•Lipid profile depends on the microalgae specie and so its ...possible use.
A fast and green process for the isolation of high value lipids from different marine microorganisms is presented involving the use of limonene, a green biodegradable solvent, as an alternative to traditional hexane extraction. The optimized process is based on pressurized liquid extraction (PLE) at 200°C for 15min using limonene:ethanol (1:1, v/v) as extracting solvent. Under these conditions, lipids were extracted from different microalgae such as Spirulina, Phormidium, Anabaena and Stigeoclonium and their composition in terms of fatty acids were studied by using a Fast-GC–MS method and compared with the original content in the raw material. The extraction method provided the best results in terms of extraction yield for Spirulina, meanwhile the highest amount of ω-3 fatty acids were obtained from Stigeoclonium.
A comparative study between “alternative” extraction processes such as centrifugal partition extraction (CPE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) and ...classical solid/liquid used in the laboratory are currently focusing on the efficiency (selectivity and productivity) to obtain bioactive phenolic compounds from the phaeophyte Sargassum muticum model. The choice of the best process was based on several measurements: (i) the total phenolic content measured by the colorimetric Folin–Ciocalteu assay, (ii) radical scavenger and antioxidant activities assessed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, and the β-carotene bleaching method and finally (iii) the method productivity. Irrespective of the solvent used in the processes, alternative methods are always sharply more effective than classical ones. With the exception of SFE which does not allow extracting the totality of the active phenolic compounds, two of the other extraction methods were particularly promising. First, CPE afforded the most important yields in concentrated phenolic compounds (PC) (22.90±0.65%DW) also displaying the best activities (0.52±0.02 and 0.58±0.19mg/mL for IC50 and AAC700, respectively). Secondly, PLE using an EtOH:water mixture 75:25 (v/v) allowed a good PC extraction (10.18±0.25%DW) with huge efficiency. Despite a lesser activity of the extracts (0.77±0.01 and 1.59±0.15mg/mL for IC50 and AAC700, respectively) PLE is a green process and potentially complies European norms requirements for the prospective valorization of phenolic compounds from S. muticum in Brittany.
► Some extraction solvents and processes were tested to obtain active phenolics from S. muticum. ► The best process choice was based on phenolic content, antioxidant activity and productivity. ► Centrifugal partition extraction afforded the most important yields in active phlorotannins. ► Pressurized liquid extraction (PLE) allowed a good phlorotannins extraction with huge efficiency. ► PLE potentially complies with the European requirements for the phenolics valorization.
This study presented an analysis of the TeO2/GeO2 molar ratio in an oxide glass system. A family of melt-quenched glasses with the range of 0–35 mol% of GeO2 has been characterized by using DSC, ...Raman, MIR, refractive index, PLE, PL spectra, and time-resolved spectral measurements. The increase in the content of germanium oxide caused an increase in the transition temperature but a decrease in the refractive index. The photoluminescence spectra of europium ions were examined under the excitation of 465 nm, corresponding to 7F0 → 5D2 transition. The PSB (phonon sidebands) analysis was carried out to determine the phonon energy of the glass hosts. It was reported that the red (5D0 → 7F2) to orange (5D0 → 7F1) fluorescence intensity ratio for Eu3+ ions decreased from 4.49 (Te0Ge) to 3.33 (Te15Ge) and showed a constant increase from 4.58 (Te20Ge) to 4.88 (Te35Ge). These optical features were explained in structural studies, especially changes in the coordination of 4Ge to 6Ge. The most extended lifetime was reported for the Eu3+ doped glass with the highest content of GeO2. This glass was successfully used for the drawing of optical fiber.
Multifunctional state assessment was the basis of time sequence design of territory spatial development and overall utilisation. This study aimed to identify the ecological-production-living (PLE) ...territory spatial function to provide a basis for territory spatial planning. It took Henan Province as the research area. This study developed a methodology to assess differentiation characteristics for PLE function, a method that integrates functional merging and geographic information technology. We used the coordination degree model and spatial autocorrelation analysis to reveal the coordination of spatial functions of the province. The results were as follows: (1) During the study period, the land production function of main grain-producing areas decreased slowly, and production and living function values of the Central Plains urban agglomeration with Zhengzhou as the centre were in an upward trend. The characteristics of urban-rural dualization were prominent, and ecological function value decreased year by year. (2) The laws of territorial spatial functions had different manifestations in different stages (1990–2005 and 2005–2018). By different characteristic laws, the change in production function in the later period was bigger than that in the previous period. The living function maintained a good continuity expansion characteristic before and after. The spatial regularity distribution characteristics of ecological function were weak, and the overall environment became worse than before. (3) The territory space of middle and low coordination function types was the most important type, and the aggregation was relatively weak. Xuchang County and Weihui City showed better states of functional coordination aggregation. Lushi County, Xinxian County, and Shangcheng County, which were in the western and southern mountainous and hilly areas, showed low-low aggregation characteristics. Thus, the government will strengthen targeted control over territorial space. This study provides a reference for the overall deployment of the development and utilisation of territory space in Henan Province.
The spatial layout of the "Production-Living-Ecological" (PLE) function and the spatial optimization of the "Urban-Agricultural-Ecological" (UAE) pattern are the key points and difficulties in ...territorial space planning. This paper analyzes their spatial concepts and holds that PLE space is a functional space, while UAE space belongs to a regional space. The optimization of the UAE pattern should be guided by the improvement of the PLE function. Therefore, taking Hefei City, China, as an example, this paper analyzes the evolution of the present UAE pattern, evaluates the PLE function under carbon constraint and then determines the improvement direction of the PLE function and finally simulates the future UAE pattern of territory space. The conclusions are as follows: ① From 2011 to 2019, the urban space increased incrementally, while the agricultural space and ecological space decreased continuously, and the urban space expansion squeezed the agricultural and ecological spaces greatly; ② The PLE functions of four districts in the main city are higher than that of five other counties. After the carbon constraint conditions are included, the PLE functions of the main city were reduced due to the relatively strong capacity of carbon source, while the counties' increased due to a stronger carbon sink capacity; ③ According to the normalized revealed comparative advantage (NRCA) index, it was determined that the functional improvement direction of each district and county are Yaohai District and Shushan District have comprehensive function as a priority, Luyang District and Baohe District give priority to living-ecological function, Changfeng County, Feidong County, Feixi County and Chaohu County give priority to production-ecological function, and Lujiang County gives priority to ecological function; ④ The simulation results show that 2025 is an important node for the evolution of the UAE pattern. The urban spatial expansion during the "14th Five-Year Plan" period will still bring great pressure on agriculture and ecological spaces, and then, the UAE pattern will continue to be optimized and balanced.
Abstract
An analytical method coupling pressurized liquid extraction (PLE), pre-concentration by thermal desorption (ATD) and analysis by GC/MSMS was developed for the quantification of pesticides in ...air and dust near vineyards crops to evaluate potential exposure of residents living near these crops. PLE was done using acetonitrile and extracts were concentrated under fume hood to 1 mL. 100 μL of the extract was spiked in a Tenax TA tube and internal standards and N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide were added before thermal desorption at 300°C for 30 min. GC/MSMS analysis was done in MRM mode and limits of quantification and limits of detection were determined for each matrix (passive air sample, active air sample and dust). The method was applied in the field and shows good sensitivity and accuracy.
PurposeThe purpose of this study is to explore the perception of the users concerning the role of artificial intelligence (AI) in enhancing personal learning profile (PLP), personal learning network ...(PLN) and personal learning environment (PLE) and their effect on the perceived ease of use, perceived effectiveness and perceived usefulness for enhancing the overall attitude and satisfaction of the e-learning.Design/methodology/approachThe data were collected from students and professionals who have ever used the e-learning module, and smart partial least square-structural equational modeling (PLS-SEM) is used to see relations between the different variables.FindingsIt was seen that the PLE is affecting both perceived ease of use and perceived usefulness. The research has shown that perceived ease of use showed a mediating effect between PLE and attitude and satisfaction. Further satisfaction mediates between perceived ease of use and intention. PLP has come out to significantly impacting perceived effectiveness. The multigroup analysis also showed that the attitude and satisfaction level affecting intention to use the e-learning module differ across the two groups of learners, i.e. gender and type of learners.Research limitations/implicationsThe data are collected from students and professionals who have ever used the e-learning module and wholly based on their perceptions, leading to self-perception bias.Originality/valueThe current research is trying to integrate the user perception of PLP, PLN, PLE into the framework of the technology acceptance model and see how they impact the overall attitude and satisfaction of the learners. AI can be used to improve them and make e-learning more adherent to the users. AI can play an essential role in generating the right environment by matching the profile of the learner.
The Clinical Spectrum of Lymphatic Disease Radhakrishnan, Kavita; Rockson, Stanley G.
Annals of the New York Academy of Sciences,
20/May , Letnik:
1131, Številka:
1
Journal Article
Recenzirano
Lymphatic disease is quite prevalent, and often not well clinically characterized. Beyond lymphedema, there is a broad array of human disease that directly or indirectly alters lymphatic structure ...and function. The symptomatic and objective presentation of these patients can be quite diverse. In this review, we have attempted to provide a systematic overview of the subjective and objective spectrum of lymphatic disease, with consideration of all of the categories of disease that primarily or secondarily impair the functional integrity of the lymphatic system. Lymphedema is discussed, along with chromosomal disorders, lymphangioma, infectious diseases, lymphangioleiomyomatosis, lipedema, heritable genetic disorders, complex vascular malformations, protein‐losing enteropathy, and intestinal lymphangiectasia.
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•Isolated cyanobacterium from the Chilean coastal desert was genus Geitlerinema.•Geitlerinema sp. showed to be a rich source of proteins and phycobiliproteins.•Extraction yield ...increased with water and high temperature under PLE.•Lipids recovery improved under polar extractants as the temperature increased.
This study presents a new cyanobacterium of the genus Geitlerinema sp. isolated from the Chilean coastal desert as a rich source of bioactive compounds. Phylogenetic tree is shown along with a broad biochemical characterization using conventional and pressurized liquid extraction. Variables as extraction yield, phycobiliproteins, lipids and methyl palmitate (C16:0) were studied by means of two experimental designs based on a response surface methodology (RSM) employing two factorial design 32. Factors as temperature (20–200 °C) and percentage of solvents were selected resulting in Factorial Design A with 0–100% (v/v) of ethanol–water and Factorial Design B with 0–100 (v/v) of ethanol–limonene solvents. The main bioactive compounds were total proteins (∼52% wt), phycobiliproteins (especially C-phycocyanin) and methyl palmitate (C16:0). Data obtained showed that water and ethanol:water (1:1, v/v) improved the extraction yield and phycobiliproteins recovery. As for ethanol:limonene extracts, they were better for lipids and methyl palmitate extractions. In general, high temperatures only improved the extraction yield whereas low temperatures favor the extraction of phycobiliproteins. Therefore, results indicated that Geitlerinema sp. could be one of the several cyanobacteria genera that display functional properties for nutritional, pharmaceutical or industrial use as sustainable and cost-effective bioactive compounds in algal biorefinery model.
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