2,664 research outputs found
Sinteza i biološka evaluacija nekih pirimidina, pirimido[2,1-b][1,3]tiazina i tiazolo[3,2-a]pirimidin derivata
4,6-Diamino-1H-pyrimidine-2-thione (1) was used for the preparation of the pyrimidine derivatives 2-5. Compound 5 was cyclized to produce pyrimido[2,1-b][1,3]thiazine derivatives 6, which was condensed with p-chlorobenzaldehyde to give compound 7. The latter compound was reacted with hydroxylamine to give isoxazolo[4,5-d]thiazino[2,3-a]pyrimidines 8. Compound 8b was treated with 2-chloroethyl methyl ether to afford compound 9. Similarly, compound 3 was reacted with chloroacetic acid to give thiazolo[3,2-a]pyrimidine 10, which was condensed with p-chlorobenzaldehyde to give compound 11. Compound 11 was condensed with hydroxylamine to give isoxazolo[4,5-d]thiazolo[2,3-a]pyrimidine 12. Compound 12b was treated with 2-chloroethyl methyl ether to afford compound 13. The biological evaluation of some prepared products showed that many of them revealed promising antimicrobial activity.4,6-Diamino-1H-pirimidin-2-tion (1) upotrebljen je kao ishodni spoj u sintezi derivata pirimidina 2-5. Spoj 5 je cikliziran u pirimido[2,1-b][1,3]tiazin derivat 6, koji je kondenziran s p-klorbenzaldehidom u spoj 7. Produkt 7 je u reakciji s hidroksilaminom dao izoksazol[4,5-d]tiazino[2,3-a]pirimidin 8. Spoj 8b je u reakciji s 2-kloretil metil eterom dao spoj 9. Slično je spoj 3 reagirao s kloroctenom kiselinom i dao tiazol[3,2-a]pirimidin 10, koji je kondenziran s p-klorbenzaldehidom u produkt 11. Spoj 11 je kondenzacijom s hidroksilaminom dao izoksazol[4,5-d]tiazolo[2,3-a]pirimidin 12. Spoj 12b je s 2-kloretil metil eterom dao produkt 13. Biološka evaluacija pokazuje da neki od sintetiziranih produkata imaju antimikrobno djelovanje
Generalized T-Q relations and the open spin-s XXZ chain with nondiagonal boundary terms
We consider the open spin-s XXZ quantum spin chain with nondiagonal boundary
terms. By exploiting certain functional relations at roots of unity, we derive
a generalized form of T-Q relation involving more than one independent Q(u),
which we use to propose the Bethe-ansatz-type expressions for the eigenvalues
of the transfer matrix. At most two of the boundary parameters are set to be
arbitrary and the bulk anisotropy parameter has values \eta = i\pi/2,
i\pi/4,... We also provide numerical evidence for the completeness of the
Bethe-ansatz-type solutions derived, using s = 1 case as an example.Comment: 23 pages. arXiv admin note: substantial text overlap with
arXiv:0901.3558; v2: published versio
Sinteza i antimikrobno djelovanje fuzioniranih heterocikličkih pirola
Pyrrole derivatives 1a,b were used as precursors for the preparation of pyrrolo[2,3-d]pyrimidine derivatives 2a,b-7a,b. Also, the formation and structure of different pyrrolotriazolopyrimidine derivatives 8a,b-11a,b were discussed. Some of the prepared products showed potent antimicrobial activity.Pirolni derivati 1a,b upotrebljeni su kao prekursori za pripravu derivata pirolo2,3-dpirimidina 2a,b7a,b. Diskutirano je i nastajanje i struktura različitih derivata pirolotriazolopirimidina 8a,b11a,b. Neki od sintetiziranih spojeva posjeduju izraženo antimikrobno djelovanje
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Production, characterization and anticancer activity of <em>Candida bombicola</em> sophorolipids by means of solid state fermentation of sunflower oil cake and soybean oil
The production of sophorolipids by <em>Candida bombicola</em> NRRL Y- 17069 grown in a mixture of sunflower oil cake and crude soybean oil as economic substrates with different fermentation techniques was studied. The highest yield (49.5 g·100 g<sup>−1</sup> substrates) was obtained from solid state fermentation after employing a new concept for extraction by methanol (E I) followed by ethyl acetate (E II), then partially purified with hexane (E III). The course of time of fermentation was also studied, and E I extracted of the 12<sup>th</sup> day showed the minimum surface tension (45 mN·m<sup>−1</sup>) at a critical micelle dilution (CMD) of 10% concentration. The produced sophorolipids were characterized and confirmed by FTIR and <sup>1</sup>H NMR spectroscopy. The anticancer activity of the produced compounds was assessed against MCF-7, HepG2, A549, HCT116 cancer cell lines and the results revealed that E III and E IV (a mixture of E I & E III) act as promising anticancer agents in HepG2 and A549 by inhibiting urokinase and histone deacetylase activities.<br><br>Se estudió la producción de soforolípidos por <em>Candida bombicola</em> NRRL Y- 17069 cultiva con diferentes técnicas de fermentación en una mezcla de torta de girasol y aceite de soja crudo, como sustratos económicos. El rendimiento más alto (49,5 g·100 g<sup>−1</sup> de sustrato) se obtuvo por fermentación en estado sólido después de extraer con metanol (IE) seguido de acetato de etilo (EII), y de purificación parcial con hexano (EIII). También se estudió el tiempo de fermentación, considerando que el extracto IE de 12 días mostró una tensión superficial mínima (45 mN·m<sup>−1</sup>) a una dilución micelar crítica (CMD) de concentración 10 %. Los soforolípidos producidos se caracterizaron y se confirmaron mediante espectroscopia FTIR y RMN de <sup>1</sup>H. La actividad anticancerígena de los compuestos producidos se evaluó en células MCF-7, HepG2, A549, líneas celulares de cáncer de HCT116 y los resultados revelaron que EIII y EIV (una mezcla de EI y EIII) actúan como prometedores agentes anticancerígenos en HepG2 y A549 inhibiendo las actividades de uroquinasa e histona desacetilasa
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