Recovery of Bioactive Phenolic Compounds from Lemon (Citrus limon (L.) Burm. f.) and Orange (Citrus Sinensis L. Osbeck) Pomaces

Supercritical Fluid Extraction (SFE) from lemon (Citrus limon (L.) Burm. f.) and orange (Citrus Sinensis L. Osbeck) pomaces was applied to obtain extracts with high phenolic content and potent antioxidant activity. The effects of extraction conditions on SFE were analyzed, temperature (40 – 60°C), pressure           (100 – 200 bar), co-solvent (25% (v/v), ethanol) for lemon pomace and pressure effect (100 – 200 bar) on SFE was investigated at 40°C in the presence of 25% (v/v) ethanol for orange pomace using the samples were 100 – 200 µm of average particle size. Moreover, in order to compare experimental data obtained by SFE, Soxhlet extractions were performed using methanol. Total phenolic contents, total flavonoid contents and antioxidant potential of extracts were assessed with Folin-Ciocalteu method, AlCl3/NaNO2 colorometric procedure and DPPH method, respectively. Experimental results showed that SC-CO2 extraction allows obtaining phenolic extracts have antioxidant activity but it presents lower yield than soxhlet extraction. In SFE process, the highest extraction yield determined at the conditions of 100 bar, 50°C and 200 bar, 40°C for lemon and orange pomaces, respectively. Despite the lower extraction yields, SFE is considered as an alternative green technology which provides extensive advantages on the extraction of natural compounds. Keywords: Lemon, Orange, Supercritical fluid extraction, Antioxidant activity, Phenolic content, Reuse of wast

NMR-spektroskopische Untersuchung von Bindungspartnern kleiner GTPasen: Bindedomänen von RalGDS und RanBP2

Die Lösungsstruktur der zweiten ranbindenden Domäne des menschlichen Kernporenproteins RanBP2 (Nup358) wurde mittels hochauflösender, mehrdimensionaler Kernspinresonanzspektroskopie aufgeklärt. Das untersuchte Proteinkonstrukt umfaßt die Aminosäurereste Glycin 2028 bis Prolin 2154 von RanBP2 und lag einheitlich mit 15N bzw. 13C und 15N markiert vor. Die Struktur ist die einer PH-Domäne (pleckstrin homology), die erreichte Auflösung liegt für den gefalteten Teil der Hauptkette bei 0,25 nm. Das Vorhandensein des fünften der gefundenen b-Stränge scheint vom Funktionszustand der Domäne, frei oder im Komplex mit Ran, abzuhängen. Der Strang fehlt in der Kristallstruktur des Komplexes der ersten Ranbindedomäne mit RanGppNHp. An der Rasbindedomäne von RalGDS (Mensch) wurden der heteronukleare Kernoverhausereffekt sowie longitudinale und transversale Relaxationsraten der Stickstoffkerne im Proteinrückgrat gemessen. Die zur Relaxation durch Dipol-Dipol-Wechselwirkung und Anisotropie der chemischen Verschiebung beitragenden spektralen Dichten wurden nach dem modellfreien Ansatz von G. Lipari und A. Szabo bestimmt. Neben dem C-Terminus erscheinen vier weitere Bereiche, die sämtlich in 'loop-Regionen' liegen, als besonders flexibel. Beweglichkeit in der freien und direkter Kontakt mit Ras in der komplexierten Domäne sind nicht korreliert. Eine neue Methode zur Bestimmung von Mittelwert und Standardabweichung zyklischer Daten wird vorgestellt. Die dafür gewählten Definitionen stimmen mit denjenigen für nichtzyklische Größen soweit als möglich überein-. Datensätze, etwa Winkel, werden in denjenigen Koordinatensystemen beschrieben, in welchen die Standardabweichung minimal ist. Es wird ein Algorithmus zur Wahl des optimalen Systems angegeben. Anhand der Hauptkettentorsionswinkel von RasGTP und RasGDP wird die Eignung der Methode zum lokalen Vergleich von Molekülstrukturen aufgezeigt

Determination temporal changes of the coastline of the Sea of Marmara in Istanbul

Coastal areas have always been attractive for humankind throughout the history. Today, it is known that nearly half of the population of the world lives on the coasts, and this ratio increases everyday. At the same time, coastal areas are also seen as places exposed to rapid changes in the world. In addition to the formal effects of the natural phenomena, human activities including the filling up projects to get area from the sea are effective factors on the coasts. Emerging technologies in conjunction with the construction of fill in coastal areas continues to increase steadily in recent years. An unplanned construction period has been experienced on the coasts of Istanbul due to rapid urbanization and wrong planning applications. This has led to significant changes in time and shoreline. Detection of temporal changes is critical for sustainable coastal development and planning. Regular data source for the history of this change that allows for the detection of satellite imagery is very important. In this study, Landsat satellite imageries were used to detect the previous and present borders of coastlines and to understand the temporal changes on these area

Use of pedestrian simulation technologies in urban planning and architectural design process Şehir planlama ve mimari tasarım sürecinde yaya simülasyonu teknolojilerinin kullanımı

Urban planners and architects have used different design criteria by following project processes different from each other through the ages. The common point of all these projects has been functionality which is one of the most important criteria for human based design. Aesthetics, beauty and similar terms may be arguable but a non-functional spatial design must not be accepted. All spaces, cities, squares, parks, roads and buildings are designed for people. If these urban structures are not suitable for them, people will have serious problems in terms of general circulation. Therefore, ergonomics and functionality terms must be the basic design criteria of all human based urban planning and architectural design processes. How may it be possible to understand an urban design project or a building is functional before constructing it? The aim of this article is to explain the benefits of pedestrian simulation technologies through the design processes in both theoretical and practical frameworks on a case study area which is an underground metro station. A capacity analysis and circulation assessment has been carried out on the metro station by using Massmotion pedestrian simulation software. Extended English summary is in the end of Full Text PDF (TURKISH) file.ÖzetGeçmişten günümüze şehir planlama ve mimarlık alanında gerçekleştirilen çalışmalarda çeşitli tasarım kriterleri kullanılmış, birbirinden farklı planlama süreçleri izlenmiştir. İnsanların kullanımına yönelik gerçekleştirilen hemen hemen tüm çalışmaların en önemli ortak noktası ise ‘kullanışlılık’ olmuştur. Estetik, güzellik ve benzeri göreceli kavramlar tartışılabilir olmakla birlikte, insanların kullanımı için tasarlanan bir yapının fonksiyonel olmaması inşa sonrasında ciddi bir sorun teşkil edecektir. Planlanan kentler, meydanlar, yollar, yapılar kullanışlı olmadığı takdirde kullanıcılar sirkülasyon anlamında sıkıntılar yaşayacaklardır. Bu nedenle gerçekleştirilen tüm şehir planlama ve mimarlık çalışmalarında hem ergonomi hem de kullanışlılık konusuna çok dikkat edilmesi gerekmektedir. Peki, kentsel tasarımı yapılan bir proje alanının ya da mimarlar tarafından tasarlanan bir yapının fonksiyonel olup olmadığı daha inşa edilmeden nasıl anlaşılabilir? Bu çalışmanın amacı, son yıllarda gelişen yaya simülasyonu teknolojilerinin mimarlık ve planlama alanındaki projelerin tasarım değerlendirme süreçlerinde kullanımının yararlarını hem teorik açıdan ortaya koymak hem de gerçekleştirilen örnek bir uygulama üzerinde göstermektir. Çalışma kapsamında bir metro istasyonuna ilişkin mimari çizimler üzerinden kapasite analizi gerçekleştirilmiş, sirkülasyon açısından değerlendirme yapılmıştır. Yaya simülasyonu kapsamında gerekli analizlerin gerçekleştirilmesi amacıyla Massmotion yazılımı kullanılmıştır

USE OF WEB-BASED GIS APPLICATIONS IN GEOGRAPHY TEACHING—THE IMPLICATIONS FROM TÜRKİYE

Geography, as a discipline which examines the earth, aims to increase analytical thinking skills by instilling spatial thinking (ST) skills in students. The youth who enrich a sense of space with these talents will effectively solve the spatial problems they encountered. In the modern world, where spatial issues are frequently being faced with, ST is extremely important for analyzing and interpreting data. Geographical information systems (GIS) appear as a method commonly used to process data and transform it into spatial information. In this context, despite the renewal of the secondary education (SE) geography curriculum in Türkiye, with the components required for the use of GIS at the SE level, prevented the use of GIS in SE from reaching the desired level. Developments in technologies have also caused significant changes in the field of GIS with the power of cloud technologies and, the work done in the personal computer environment has been moved to the internet environment. Web GIS applications, which can be used via a web browser, are much easier to use than desktop software and can reach many users from any device with the internet. Within the scope of the study, a sample application was designed to use web GIS tools in geography teaching. With the application, it is possible to assess the students’ achievements in the geography lessons regarding verbal and spatial data. Thus, it was aimed to ensure the active participation of the students in the geography lessons, develop their ST ability, and perception of space

Purification of supercritical-fluid carotenoid-rich extracts by hydrophobic interaction chromatography

Supercritical fluid extraction (SFE) has been widely used for extracting several valuable phytochemicals, including carotenoids. However, there is a scarcity of works dealing with the purification of SFE extracts. The aim of this work was to assess the feasibility and efficiency of a hydrophobic interaction chromatography (HIC) protocol for purifying carotenoid-rich extracts obtained by SFE. Initial batch experiments were carried out to calculate the resin adsorption capacity and adsorption kinetics. Subsequent runs were performed in a manually-packed chromatographic column, using the Amberlite XAD-1180N resin, where breakthrough curves and adsorption isotherms were obtained and fitted to the Langmuir model. The antioxidant activity and carotenoid degradation rates were monitored throughout the processes. In batch, the resin presented a maximum carotenoid adsorption capacity of 1.89 μg/mg, while in column, this value increased to 10.4 μg/mg. The global carotenoid adsorption rate was 93.3% and the elution rate, 94.7%, resulting in a global recovery of 88.4% for total carotenoids and 92.1% for carotenes. The Langmuir model fitted well the experimental data. Analysis of the extracts demonstrated that a 5.5-fold reduction in extract mass was achieved, accompanied by a 4.7-fold and 2.1-fold increase in carotenoid concentration and antioxidant activity, respectively. This work presents a novel process based on preparative HIC for the purification of carotenoid extracts and provides a fundamental understanding on process performance. It is potentially scalable and can be implemented in extraction and purification of carotenoids from natural sources, as an alternative to their production through chemical synthesis

Optimisation and modelling of supercritical CO2 extraction process of carotenoids from carrot peels

This work aimed to assess and optimise the extraction of carotenoids from carrot peels by supercritical CO2 (S-CO2), utilising ethanol as co-solvent. The evaluated variables were temperature, pressure and co-solvent concentration. According to the validated model, the optimal conditions for maximum mass yield (5.31%, d.b.) were found at 58.5 °C, 306 bar and 14.3% of ethanol, and at 59.0 °C, 349 bar and 15.5% ethanol for carotenoid recovery (86.1%). Kinetic experiments showed that 97% of the total extractable carotenoid content was recovered after only 30 min, whereas model fitting confirmed the fast extraction trend and desorbing nature of carotenoids from the sample matrix. The process is potentially scalable, as demonstrated by runs performed with a 10-fold initial sample size, which led to even higher recoveries (96.2%), indicating that S-CO2 can be as efficient as a conventional solvent extraction for recovering high value compounds from vegetable by-products

Homology modeling and molecular dynamics simulations of MUC1-9/H-2Kb complex suggest novel binding interactions

International audienceHuman MUC1 is over-expressed in human adenocarcinomas and has been used as a target for immunotherapy studies. The 9-mer MUC1-9 peptide has been identified as one of the peptides which binds to murine MHC class I H-2K. The structure of MUC1-9 in complex with H-2K has been modeled and simulated with classical molecular dynamics, based on the x-ray structure of the SEV9 peptide/H-2K complex. Two independent trajectories with the solvated complex (10 ns in length) were produced. Approximately 12 hydrogen bonds were identified during both trajectories to contribute to peptide/MHC complex, as well as 1-2 water mediated hydrogen bonds. Stability of the complex was also confirmed by buried surface area analysis, although the corresponding values were about 20% lower than those of the original x-ray structure. Interestingly, a bulged conformation of the peptide's central region, partially characterized as a -turn, was found exposed form the binding groove. In addition, P1 and P9 residues remained bound in the A and F binding pockets, even though there was a suggestion that P9 was more flexible. The complex lacked numerous water mediated hydrogen bonds that were present in the reference peptide x-ray structure. Moreover, local displacements of residues Asp4, Thr5 and Pro9 resulted in loss of some key interactions with the MHC molecule. This might explain the reduced affinity of the MUC1-9 peptide, relatively to SEV9, for the MHC class I H-2K