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Meyan kökü (Glycyrrhiza glabra) ekstrelerinin ve bazı aktif bileşenlerinin monoaminoksidaz A ve monoaminoksidaz B aktiviteleri üzerine etkileri
Get PDFMeyan Kökü (Glycyrrhiza glabra) Ekstrelerinin ve Bazı Aktif Bileşenlerinin Monoaminoksidaz A ve Monoaminoksidaz B Aktiviteleri üzerine etkileri Yaşlanma hücre hasarına sebep olan ve bunun sonucu olarak fizyolojik işlevlerde hatalara yol açan dejeneratif bir süreçtir. Hem Alzheimer hem de Parkinson hastalıklarında beyinde nöroaminlerin seviyelerinde azalma gözlemlenen önemli bir semptomdur ve bu nöroaminlerin yerine geri konulması veya monoamin oksidaz (MAO) gibi enzimler tarafından bozunmalarının engellenmesi bu hastalıkların etkilerinin azaltılmasında önemli bir rol oynamaktadır. Monoamin oksidaz MAO, (EC 1.4.3.4) kofaktör olarak flavin-adenin dinükleotid (FAD) bulunduran, ve çeşitli nöroaminlerin oksidasyonlarını katalizleyen bir enzimdir. İnsanda iki izoform halinde (MAO-A ve MAO-B) bulunur. Monoamino oksidaz enzimlerinin inhibisyonunun nörodejeneratif rahatsızlıklarda sıklıkla gözlemlenen nöroamin azalmasının önüne geçilmesi için önemli bir yaklaşım olduğu bilinmektedir. Bu nedenle doğal kaynaklardan elde edilmiş veya sentetik temelli pek çok farklı MAO inhibitörleri geliştirilmektedir. Meyan bitkisi (Glycyrrhiza glabra) ve bu bitkinin kökleri insanlar tarafından yüzlerce yıldır doğal ilaçlar olarak kullanılan doğal materyallerdir. Yapılan çalışmalar meyan kökü ekstrelerinin MAO inhibisyonunu sağlayabileceğini göstermektedir. Bu nedenle bu tez çalışmasında farklı yöntemlerle hazırlanmış meyan kökü ekstraktlarının, geleneksel meyan kökü içeceklerinin, ve meyan kökünün başlıca bileşenlerinden olan glisirizik asit, likuiritin ve izolikuiritinin MAO enzimleri üzerindeki etkileri in vitro ve in silico olarak incelenmiştir. Bu amaçla meyan kökleri artan polaritede çözücülerle (hekzan, kloroform, aseton, etil asetat, metanol ve su) fraksiyonlu olarak (FEE) ve ayrı ayrı doğrudan (DEE) ekstre edilmiş ve içerdikleri toplam fenolik madde ve toplam flavanoid içerikleri belirlenmiştir. En yüksek toplam fenolik madde içeriği su ile doğrudan ekstraksiyon sonucunda (Su DEE; 357,937 ± 5,686 mg GA/ g KM) bulunurken, en yüksek toplam flavonoid aktivitesi etil asetat ile doğrudan ekstraksiyon sonucunda (Etil asetat DEE; 39,46 ± 2,234 mg kuersetin/ mg KM) bulunmuştur. DPPH süpürücü etki incelemesinde en aktif ekstre su ile doğrudan ekstraksiyon sonucunda elde edilen ekstredir (Su DEE; IC50 0,072 ± 0,003 mg KM/ mL). Daha sonra bu ekstrelerin monoamino oksidaz A ve B enzimleri üzerindeki aktiviteleri substrat olarak tiramin kullanılar ölçülmüş ve en yüksek MAO-B inhibe edici aktivite 0,0013 mg KM/ mL IC50 değeri ile aseton fraksiyonundan elde edilmiştir. Bu ekstre MAO-B’yi MAO-A’ya kıyasla 6 kattan fazla inhibe etmektedir. Bu ekstrelerin yanı sıra geleneksel yöntemlerle hazırlanmış meyan içeceklerinin de toplam fenolik madde ve toplam flavonoid madde miktarları, antioksidan ve MAO inhibe edici etkileri incelenmiştir. Meyan içinde MAO inhibisyonunda etkileri olabileceği düşünülen ve meyan kökünde en yüksek miktarda bulunan glisirizik asit, likuiritin ve izolikuiritin bileşiklerinin MAO enzimleri üzerindeki etkileri incelenmiş ve düşük-orta seviyede etkili oldukları bulunmuştur. Bu sonuçlar ışığında meyan kökünün özellikle MAO-B enzimini inhibe edecek yeni bileşiklerin izole edilmesi için çok önemli bir kaynak olduğu ortaya konmuştur.Effects of Licorice Root (Glycyrrhiza glabra) Extracts and Some Active Ingredients on Monoamine oxidase A and Monoamine oxidase B Activities Aging is basically a degenerative process associated with impaired metabolism and causes cell damage that results in a decline in all physiological functions. Decreased levels of neuroamines in the brain are an important symptom observed in both Alzheimer's and Parkinson's diseases, and the replacement of these neuroamines or the prevention of their degradation by enzymes such as monoamine oxidase (MAO) plays an important role in reducing the effects of these diseases. Monoamine oxidase MAO (EC 1.4.3.4) is an enzyme that contains flavin-adenine dinucleotide (FAD) as a cofactor and catalyzes the oxidation of various neuroamines. There are two isoforms in humans, MAO-A and MAO-B. It is known that inhibition of monoamino oxidase enzymes is an important approach to prevent neuroamine reduction, which is often observed in neurodegenerative disorders. For this reason, many different MAO inhibitors, derived from natural sources or synthetically based, are being developed. The licorice plant (Glycyrrhiza glabra) and its roots are natural materials that have been used by humans for hundreds of years as natural remedies. Studies show that licorice root extracts can inhibit MAO activity. Therefore, in this thesis study, the effects of licorice root extracts prepared by different methods, traditional licorice root drinks, and glycyrrhizic acid, liquiritin and isoliquiritin, which are the main components of licorice root, on MAO enzymes were investigated in vitro and in silico. For this purpose, licorice roots were extracted with solvents with increasing polarity (hexane, chloroform, acetone, ethyl acetate, methanol and water) in fractions (FEE) or directly (DEE), and their total phenolic compound and total flavonoid contents were determined. The highest total phenolic content was found as a result of direct extraction with water (Water DEE; 357.937 ± 5,686 mg GA/ g DM), while the highest total flavonoid activity was found as a result of direct extraction with ethyl acetate (Ethyl acetate DEE; 39.46 ± 2.234 mg quercetin/ g DM). In the DPPH scavenging effect analysis, the most active extract is the one obtained as a result of direct extraction with water (Water DEE; IC50 0.072 ± 0.003 mg DM/ mL). Then, the activities of these extracts on monoamine oxidase A and B enzymes were measured using tyramine as substrate, and the highest MAO-B inhibitory activity was obtained from the acetone fraction with an IC50 value of 0.0013 mg KM/ mL. This extract inhibits MAO-B more than 6 times compared to MAO-A. In addition to these extracts, the total phenolic substance and total flavonoid substance content, antioxidant and MAO inhibitory effects of traditional licorice drinks were also investigated. The effects of glycyrrhizic acid, liquiritin and isoliquiritin compounds, which are thought to have effects on MAO inhibition in licorice and are found in the highest amount in licorice root, on MAO enzymes were examined and they were found to be effective at low-moderate levels. These results suggests that licorice root is a very important source for isolating new compounds that may act as inhibitors of the MAO-B enzyme
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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