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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
Synthesis and biological activity screening of amide, hydrazide and hydroxamic acid derivatives of a group of heterocyclic compounds
No full textEnzimler vücuttaki birçok biyokimyasal reaksiyonun gerçekleşmesine aracılık eden
protein yapısındaki makromoleküllerdir ve bu nedenle ilaç geliştirme çalışmalarında
terapötik olarak önemli hedeflerdir. Bugün tedavide kullanılan ilaçların büyük bir
kısmı enzim inhibitörü olarak etkinlik göstermektedir.
Miyeloperoksidaz (MPO) nötrofillerde bulunan ve antibakteriyel etkinliğin
gerçekleştirilmesine aracılık eden bir enzimdir. Fagozom içerisinde hidrojen peroksit
(H2O2) ile çeşitli halojenler arasındaki reaksiyonu katalizleyerek hipohalöz asitlerin
sentezine aracılık eder. Hipohalöz asitler ise bakterilerin biyomoleküllerini
oksitleyerek antibakteriyel etkinliği sağlar. MPO sadece hücre içinde değil hücre
dışında da aktiftir ve çeşitli sebeplerle nötrofil içerisinden salındığında enzimatik
döngüsünü hücre dışı ortamda bulunan reaktif biyoajanlarla gerçekleştirir ve oluşan
hipohalöz asitler konağa ait biyolojik makromolekülleri oksitleyerek inflamasyon
oluşma sürecini tetikleyen kimyasal değişikliklere sebep olur. Akut ve kronik
inflamasyon süreçleri, kardiyovasküler hastalıklar, kanser, nörodejeneratif hastalıklar,
romatoid artrit, renal hastalıklar gibi birçok durumun patolojisinde rol oynamaktadır.
MPO’nun önemli patofizyolojik olaylarda görev aldığının tespit edilerek birçok
inflamatuar hastalıkla ilişkilendirilmesi, bu hastalıkların tedavi stratejileri açısından
yeni ve etkin MPO inhibitörlerinin geliştirilmesini önemli bir hedef haline getirmiştir.
Son yıllarda gerçekleştirilen çalışmalarda MPO’nun yapısının daha detaylı
aydınlatılmasıyla birlikte MPO enzimi, ilaç geliştirme çalışmalarında ilgi çeken bir
terapötik hedef olmuştur.
Tez çalışması kapsamında, MPO inhibitör etkinlik göstermesi beklenen benzimidazol
türevi bileşiklerin tasarımı, sentezi, biyoaktivite ve sanal moleküler kenetlenme
çalışmaları gerçekleştirilmiştir. Bu amaçla benzimidazol-2-tiyon halkasının azot
atomunun, amit, hidrazit ve hidroksamik asit fonksiyonel grupları taşıyan yan zincirle
sübstitüe edilmesi planlanmıştır. Benzimidazol-2-tiyon halkasının azot atomundan
alkilasyonu denenmiş ancak reaksiyon benzimidazol-2-iltiyo alkanamit türevleri ile
sonuçlanmıştır. Bu nedenle çalışmamıza benzimidazol-2-iltiyo alkanamit türevleri de
dahil edilmiştir. 2-tiyokso-benzimidazol alkanamit, alkanhidrazit, alkanhidroksamik asit türevlerinin sentezi için ise farklı yeni bir sentez yolağı geliştirilmiştir. Bu
yöntemde ilk olarak benzimidazol-2-on halkası aracılığıyla 2-klorobenzimidazol elde
edilmiş, sonrasında hedef bileşikler olan 2-tiyokso-benzimidazol alkanamit,
alkanhidrazit ve alkanhidroksamik asit türevleri sentezlenmiştir.
Sentezi tamamlanan bileşiklerin yapıları IR, 1H NMR, 2D NMR (HSQC-HMBC), 13C
NMR ve Kütle Spektroskopileri, bazı örneklerde ise elementel analiz kullanılarak
doğrulanmıştır. Ayrıca yapının kesinleştirilmesi amacıyla iki bileşiğin (B10 ve BS6)
X-Ray analizleri yapılmıştır.
Biyolojik aktivite testleri hem kükürt hem de azot sübstitüe türevler için
gerçekleştirilmiştir. Ayrıca kükürt atomunun bileşikteki varlığının MPO inhibisyonu
üzerindeki etkisini değerlendirmek amacıyla ara ürün olarak sentezlenen 2-
klorobenzimidazol türevlerinin de aktiviteleri test edilmiştir. %70 ve üzeri MPO
inhibisyonu gösteren bileşiklerin IC50 değerleri belirlenmiştir. Yapılan çalışmalar
sonucunda en iyi aktivite gösteren bileşik BS18 [2-(2-tiyokso-2,3-dihidro-1Hbenzo[
d]imidazol-1-il)asetohidrazit] (IC50: 0.393 μM) olarak tespit edilmiştir. Bu
bileşikten sonraki en aktif türevler BS12 [N-(2-metoksifenil)-2-(2-tiyokso-2,3-
dihidro-1H-benzo[d]imidazol-1-il)asetamit] (IC50: 3.718 μM) ve BS10 [N-(3-
metilfenil)-2-(2-tiyokso-2,3-dihidro-1H-benzo[d]imidazol-1-il)asetamit] (IC50: 3.855
μM) kodlu bileşiklerdir.
Moleküler kenetlenme çalışmaları %90 ve üzerinde MPO inhibitör etkinlik gösteren
bileşikler için gerçekleştirilmiş ve bileşiklerin yapısal farklılıklarının enzim aktif
yöresindeki etkileşimleri üzerinde yol açtığı olası değişimler incelenmiştir.
Benzimidazol-2-tiyon türevlerinin MPO inhibitör geliştirme çalışmaları açısından iyi
bir başlangıç olabileceği sonucuna varılmıştır.Enzymes are protein structured macromolecules and mediate various biochemical
reactions in body therefore, they are significant therapeutic targets in drug discovery
studies. Most of the drugs, used in treatment today, demonstrate their efficiency as
enzyme inhibitors.
Myeloperoxidase (MPO) is an enzyme found in neutrophils and mediates antibacterial
activity. It catalyses the reaction between hydrogen peroxide (H2O2) and various
halogens which results in synthesis of hypohalous acids those provide antibacterial
activity through oxidizing biomolecules of bacteria. MPO is active not only inside but
also outside of the cells and when it is released from neutrophils due to various reasons,
it completes its enzymatic circle via reactive bioagents in extracellular environment.
The synthesized hypohalous acids there oxidize biologic macromolecules of the host
and this leads to trigger inflammation process by certain chemical changes. Acute and
chronic inflammation have roles in the pathology of complications such as
cardiovascular diseases, cancer, neurodegenerative diseases, rheumatoid arthritis,
renal diseases etc. Since the understanding of MPO expanded, it has been unveiled that
MPO plays role on important pathophysiological cases in many inflammatory
diseases. On this basis, development of novel and effective MPO inhibitors emerged
as one of the significant strategies in the treatment of these diseases. As recent studies
have clarified the structure of MPO in detail, it has been an attractive therapeutical
target in drug discovery studies.
In this dissertation, in the pursuit of MPO inhibitors, benzimidazol derived compounds
designed and synthesized, then biological activity and molecular docking studies were
carried out. To attain this aim, substitution of nitrogen atom on benzimidazole-2-thione
ring with a side chain carrying amide, hydrazide and hydroxamic acid functional
groups has been planned. The alkylation of benzimidazole-2-thione ring on nitrogen
atom had been tried first but the reaction resulted in benzimidazole-2-ylthio
alkanamide derivatives. Therefore, benzimidazol-2-ylthio alkanamide derivatives
were also included in our study. A new synthesize pathway has been developed for the synthesis of 2-thioxo-benzimidazole alkanamide, alkanhydrazide and
alkanhydroxamic acid derivatives. In this method, 2-chlorobenzimidazole has been
realized through benzimidazole-2-one, then the targeted 2-thioxo-benzimidazole
alkanamide, alkanhydrazide and alkanhydroxamic acid derivatives were synthesized.
The structures of synthesized compounds have been verified by IR, 1H NMR, 2D NMR
(HSQC-HMBC), 13C NMR and MASS Spectroscopical methods and elemental
analysis for some compounds. Additionally, the X-ray structures of two compounds
(B10 and BS6) have been revealed.
Biological activity studies have been performed on both sulphur and nitrogen
substituted derivatives. Also, to evaluate the impact of presence of sulphur atom in the
structure on MPO inhibition, the biological activity of 2-chlorobenzimidazole
derivatives has been investigated. IC50 values have been determined for the compounds
over 70% MPO inhibitory activity. Considering the obtained data, BS18 [2-(2-thioxo-
2,3-dihydro-1H-benzo[d]imidazol-1-yl)acetohydrazide] (IC50: 0.393 μM) has been
found as the most active compound, followed by BS12 [N-(2-methoxyphenyl)-2-(2-
thioxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)acetamide] (IC50: 3.718 μM) and BS10
[N-(3-methylphenyl)-2-(2-thioxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)acetamide]
(IC50: 3.855 μM).
Molecular docking studies have been performed on the compounds demonstrating
over 90% MPO inhibitor activity and possible interactional changes caused by
structural disparities of the compounds have been investigated at the enzyme active
site.
It has been concluded that benzimidazole-2-thione derivatives would be a good
starting point on MPO inhibitor development studies
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
Potansiyel aktif bir grup heterosiklik bileşiğin sentez çalışmaları
No full textMiyeloperoksidaz (MPO), üretimini katalizlediği başta hipokloröz asit olmak üzere güçlü oksidatif ürünler aracılığıyla insan immün sistemi için önemli destekleyici görevleri olan bir enzimdir. Ancak, MPO’nun fizyolojik rolünden sorumlu olan bu oksidatif ürünlerin kontrolden çıkarak konak biyomoleküllerinde de hasar meydana getirmesi nedeniyle MPO, başta inflamatuvar sendromlar olmak üzere pek çok patolojik durumla da ilişkilendirilmiş ve ilgi çeken bir terapötik hedef haline gelmiştir. Bu bilgilerden yola çıkılarak, çalışmamızda potansiyel miyeloperoksidaz inhibitörü oldukları düşünülen bir grup benzimidazol türevi bileşik tasarlanmış ve sentezlenmiştir.Although myeloperoxidase is an enzyme with an important supporting role on human immune system through the formation of strong oxidative products, it is also known that these products can cause tissue damage by oxidation of biomolecules which lead to inflammatory syndromes. Therefore, MPO has recently become a remarkable therapeutic target. In this study, benzimidazole derivatives were designed and synthesized as potential MPO inhibitors
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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