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Synthesis and characterization of a 9a-macrozone derived from 4-aminobenzoic acid and salicylaldehyde derivatives
No full textPrekomjerna uporaba antibiotika dovela je do naglog razvijanja rezistencije na antibiotike te je potreban razvoj novih. Jedan od najčešće korištenih antibiotika je azitromicin, antibiotik koji pripada skupini makrolidnih antibiotika. Makrozoni su spojevi koji nastaju reakcijom makrolida, tj. azitromicina i tiosemikarbazona. Tiosemikarbazoni mogu djelovati antibakterijski i antiupalno, a njihovi kompleksi s prijelaznim metalima poput bakra ili nikla dodatno povećavaju biološku aktivnost. U ovom radu pripravljeni su tiosemikarbazoni iz 4-aminobenzojeve kiseline i derivata salicilaldehida. Zatim su pripremljeni odgovarajući makrozoni reakcijom 9a-aminopropilnog derivata azitromicina i prethodno pripravljenih tiosemikarbazona. Pripravljeni su kompleksi makrozona s niklom(II) i bakrom(II). Spojevi sintetizirani u svakom koraku karakterizirani su spektroskopijom NMR te je ispitana njihova biološka aktivnost.Excessive use of antibiotics has led to bacterial resistance to antibiotics, and the development of new ones is urgently needed. One of the most commonly used antibiotics is azithromycin, an antibiotic that belongs to the group of macrolide class. Macrozones are compounds formed by the reaction of macrolides, i.e. azithromycin and thiosemicarbazones. Thiosemicarbazones can have antibacterial and anti-inflammatory effects and their complexes with transition metals such as copper or nickel further increase biological activity. In this thesis, thiosemicarbazones were prepared from 4-aminobenzoic acid and salicylaldehyde derivatives. Subsequently, the corresponding macrozones were prepared by the reaction of the 9a-aminopropyl derivative of azithromycin and previously prepared thiosemicarbazones. Finally, macrozone complexes with nickel(II) and copper(II) were prepared. The compounds synthesized in each step were characterized by NMR spectroscopy and their biological acivities were evaluated
Synthesis and characterization of a 9a-macrozone derived from 4-aminobenzoic acid and salicylaldehyde derivatives
No full textPrekomjerna uporaba antibiotika dovela je do naglog razvijanja rezistencije na antibiotike te je potreban razvoj novih. Jedan od najčešće korištenih antibiotika je azitromicin, antibiotik koji pripada skupini makrolidnih antibiotika. Makrozoni su spojevi koji nastaju reakcijom makrolida, tj. azitromicina i tiosemikarbazona. Tiosemikarbazoni mogu djelovati antibakterijski i antiupalno, a njihovi kompleksi s prijelaznim metalima poput bakra ili nikla dodatno povećavaju biološku aktivnost. U ovom radu pripravljeni su tiosemikarbazoni iz 4-aminobenzojeve kiseline i derivata salicilaldehida. Zatim su pripremljeni odgovarajući makrozoni reakcijom 9a-aminopropilnog derivata azitromicina i prethodno pripravljenih tiosemikarbazona. Pripravljeni su kompleksi makrozona s niklom(II) i bakrom(II). Spojevi sintetizirani u svakom koraku karakterizirani su spektroskopijom NMR te je ispitana njihova biološka aktivnost.Excessive use of antibiotics has led to bacterial resistance to antibiotics, and the development of new ones is urgently needed. One of the most commonly used antibiotics is azithromycin, an antibiotic that belongs to the group of macrolide class. Macrozones are compounds formed by the reaction of macrolides, i.e. azithromycin and thiosemicarbazones. Thiosemicarbazones can have antibacterial and anti-inflammatory effects and their complexes with transition metals such as copper or nickel further increase biological activity. In this thesis, thiosemicarbazones were prepared from 4-aminobenzoic acid and salicylaldehyde derivatives. Subsequently, the corresponding macrozones were prepared by the reaction of the 9a-aminopropyl derivative of azithromycin and previously prepared thiosemicarbazones. Finally, macrozone complexes with nickel(II) and copper(II) were prepared. The compounds synthesized in each step were characterized by NMR spectroscopy and their biological acivities were evaluated
Editiranje genoma pomoću sustava CRISPR/Cas9
No full textOtkriće strukture molekule DNK dovelo je do procvata biokemije te raznih otkrića koja su
omogućila razvoj raznih načina za editiranje genoma. Jedan od tih načina je korištenje
CRISPR/Cas sustava. Ovi sustavi dijele se u dvije klase, a najistraženiji je CRISPR/Cas9
sustav. Od raznih otkrivenih CRISPR/Cas sustava, CRISPR/Cas9 pokazao se kao najbolja
opcija za editiranje genoma. CRISPR/Cas9 sustav u prirodi se nalazi u bakterijama i dio je
njihovog imunološkog odgovora na viruse. Od otkrića CRISPR-a do usavršavanja
CRISPR/Cas9 sustava za editiranje genoma koje još uvijek traje, prošlo je mnogo godina u
kojima su znanstvenici otkrivali dio po dio CRISPR/Cas9 slagalice. Jednostavost i dostupnost
velika je prednost ovog sustava, ali još uvijek postoje dijelovi mehanizma djelovanja sustava
koji ga čine nesigurnim za korištenje. Otkrićem inhibitora CRISPR sustava te daljnjim
razvojem njihova djelovanja moguć je razvoj CRISPR/Cas9 sustava sigurnog za korištenje.
Jednostavnost korištenja ovog sustava čini ga izvrsnim alatom za mnoge primjene i trenutno se
provode razna istraživanja za primjenu na raznim bolestima te modifikacijama biljaka. U 2020.
godini je za otkriće CRISPR/Cas9 genetskih škara dodijeljena Nobelova nagrada za kemiju
Synthesis and characterization of a 9a-macrozone derived from 4-aminobenzoic acid and salicylaldehyde derivatives
No full textPrekomjerna uporaba antibiotika dovela je do naglog razvijanja rezistencije na antibiotike te je potreban razvoj novih. Jedan od najčešće korištenih antibiotika je azitromicin, antibiotik koji pripada skupini makrolidnih antibiotika. Makrozoni su spojevi koji nastaju reakcijom makrolida, tj. azitromicina i tiosemikarbazona. Tiosemikarbazoni mogu djelovati antibakterijski i antiupalno, a njihovi kompleksi s prijelaznim metalima poput bakra ili nikla dodatno povećavaju biološku aktivnost. U ovom radu pripravljeni su tiosemikarbazoni iz 4-aminobenzojeve kiseline i derivata salicilaldehida. Zatim su pripremljeni odgovarajući makrozoni reakcijom 9a-aminopropilnog derivata azitromicina i prethodno pripravljenih tiosemikarbazona. Pripravljeni su kompleksi makrozona s niklom(II) i bakrom(II). Spojevi sintetizirani u svakom koraku karakterizirani su spektroskopijom NMR te je ispitana njihova biološka aktivnost.Excessive use of antibiotics has led to bacterial resistance to antibiotics, and the development of new ones is urgently needed. One of the most commonly used antibiotics is azithromycin, an antibiotic that belongs to the group of macrolide class. Macrozones are compounds formed by the reaction of macrolides, i.e. azithromycin and thiosemicarbazones. Thiosemicarbazones can have antibacterial and anti-inflammatory effects and their complexes with transition metals such as copper or nickel further increase biological activity. In this thesis, thiosemicarbazones were prepared from 4-aminobenzoic acid and salicylaldehyde derivatives. Subsequently, the corresponding macrozones were prepared by the reaction of the 9a-aminopropyl derivative of azithromycin and previously prepared thiosemicarbazones. Finally, macrozone complexes with nickel(II) and copper(II) were prepared. The compounds synthesized in each step were characterized by NMR spectroscopy and their biological acivities were evaluated
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
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