159 research outputs found
Фрагменти до біографії І. Мазепи
Мета цієї статті увести до наукового обігу три документи, які стосуються життя й діяльності І. Мазепи. Перший з них нами було виявлено у польських архівосховищах. Автором цього листа, адресованого, очевидно, королеві Яну III Собеському, був учасник посольства Речі Посполитої до Москви, яке очолював вармінський біскуп і коронний канцлер Августин Міхал Радзейовський. Лист важливий тим, що проливає світло на малознаний період біографії Івана Мазепи, коли той був генеральним осавулом на лівобічній Гетьманщині. Другий і третій документи мають меншу цінність. Один з них - це типова рукописна газета - “новина”, у якій повідомляється про польсько-російські переговори у Варшаві у 1695 р. у зв’язку з азово-дніпровськими походами, у котрих визначну роль відіграли українські війська на чолі з гетьманом Іваном Мазепою. Автором наступного документа був Лаврентій Крщонович, визначний церковний діяч, ігумен деяких православних монастирів Гетьманщини, зокрема Свято-Троїцького Іллінського у Чернігові
α,β-D-Constrained Nucleic Acids Are Strong Terminators of Thermostable DNA Polymerases in Polymerase Chain Reaction
(SC5′, RP) α,β-D- Constrained Nucleic Acids (CNA) are dinucleotide building blocks that can feature either B-type torsional angle values or non-canonical values, depending on their 5′C and P absolute stereochemistry. These CNA are modified neither on the nucleobase nor on the sugar structure and therefore represent a new class of nucleotide with specific chemical and structural characteristics. They promote marked bending in a single stranded DNA so as to preorganize it into a loop-like structure, and they have been shown to induce rigidity within oligonucleotides. Following their synthesis, studies performed on CNA have only focused on the constraints that this family of nucleotides introduced into DNA. On the assumption that bending in a DNA template may produce a terminator structure, we investigated whether CNA could be used as a new strong terminator of polymerization in PCR. We therefore assessed the efficiency of CNA as a terminator in PCR, using triethylene glycol phosphate units as a control. Analyses were performed by denaturing gel electrophoresis and several PCR products were further analysed by sequencing. The results showed that the incorporation of only one CNA was always skipped by the polymerases tested. On the other hand, two CNA units always stopped proofreading polymerases, such as Pfu DNA polymerase, as expected for a strong replication terminator. Non-proofreading enzymes, e.g. Taq DNA polymerase, did not recognize this modification as a strong terminator although it was predominantly stopped by this structure. In conclusion, this first functional use of CNA units shows that these modified nucleotides can be used as novel polymerization terminators of proofreading polymerases. Furthermore, our results lead us to propose that CNA and their derivatives could be useful tools for investigating the behaviour of different classes of polymerases
Polymorphism: an evaluation of the potential risk to the quality of drug products from the Farmácia Popular Rede Própria
Polymorphism in solids is a common phenomenon in drugs, which can lead to compromised quality due to changes in their physicochemical properties, particularly solubility, and, therefore, reduce bioavailability. Herein, a bibliographic survey was performed based on key issues and studies related to polymorphism in active pharmaceutical ingredient (APIs) present in medications from the Farmácia Popular Rede Própria. Polymorphism must be controlled to prevent possible ineffective therapy and/or improper dosage. Few mandatory tests for the identification and control of polymorphism in medications are currently available, which can result in serious public health concerns
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