1,744 research outputs found
Antimicrobial Activity of Flavonoids against Extended-Spectrum β-Lactamase (ESβL)-Producing Klebsiella pneumoniae
Purpose: In the present study, six flavonoids (5,7-dimethoxyflavanone-4'-O-β-D-glucopyranoside, 5,7- dimethoxyflavanone-4'-O-[2''-O-(5'''-O-trans-cinnamoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside, naringenin-7-O-β-D-glucopyranoside, 5,7,3'-trihydroxy-flavanone-4'-O-β-D-glucopyranoside, rutin, and nicotiflorin) isolated from Galium fissurense, Viscum album ssp. album and Cirsium hypoleucum were screened against extended-spectrum β-lactamase producing multidrug-resistant (trimetoprimesulphametoxazole, sulbactam-ampicillin, clavulonate-amoxicilin, ceftriaxon, cefepime, imipenem, ceftazidime, tobramicin, gentamicin, ofloxacin, ciprofloxacin) bacteria Klebsiella pneumoniae (ESβLs). Methods: We performed susceptibility testing according to the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS) and used an inhibition endpoint for determination of the minimum inhibition concentrations (MICs). Results: All the flavonoids showed in vitro antimicrobial activity against all the isolated strains of K. pneumoniae similar to the control antibacterial (ofloxacin) at the concentrations of 32 - 64 μg ml-l; another control, ampicillin, had no activity. Since, ESβL-producing strains are known to be resistant to all β-lactam antibiotics, our results fall notably within the concentration range for antimicrobial activity. Conclusion: To the best of our knowledge, this is the first report of the study of the activity of these flavonoids against (ESβL)-producing K. pneumoniae and may throw light to the low-toxicity of flavonoids, and their potentials for developing therapies for infections caused by ESβL-producing bacteria in the future. Further work is under investigation to identify their precise antibacterial mechanism. Keywords: Antimicrobial activity, ESβLs, Flavonoids, Klebsiella pneumoniae, Ofloxacin, Ampicillin.Tropical Journal of Pharmaceutical Research Vol. 7(4) 2008: pp. 1151-115
Some rings for which the cosingular submodule of every module is a direct summand
The submodule Z(M) = ∩{N | M/N is small in its injective hull} was introduced by Talebi and Vanaja
in 2002. A ring R is said to have property (P ) if Z(M) is a direct summand of M for every R-module M . It is
shown that a commutative perfect ring R has (P ) if and only if R is semisimple. An example is given to show that
this characterization is not true for noncommutative rings. We prove that if R is a commutative ring such that the class
{M ∈ Mod−R | ZR(M) = 0} is closed under factor modules, then R has (P ) if and only if the ring R is von Neumann
regular
Evaluation of the anatomical measurements of the temporomandibular joint by cone-beam computed tomography
Background: To examine the detailed anatomy of the normal temporomandibular joint (TMJ) in a large series of patients divided into different age groups.
Materials and methods: Cone-beam computed tomography images of 100 patients included in the study. Morphometric analysis regarding mandibular con- dyle and mandibular fossa, articular tubercle and the zygomatic arch was done. The volumetric and surface measurements of mandibular condyles (total tissue volume [TV], total bone volume [BV], bone surface area [BS] and percentage of bony tissue of the mandibular condyle [BV/TV]) were also measured.
Results: Statistical analysis was performed and statistically significant differences according to the side of the joint, sex, and age groups were reported. Additionally, correlations between aging and all of these parameters were also determined.
Conclusions: TV, BV, BS and BV/TV parameters according to side, age, and sex groups were defined for normal TMJ which may help to understand the onset and progress of TMJ disorders.
Mutagenic and antimutagenic properties of some lichen species grown in the Eastern Anatolia Region of Turkey
All the methanol extracts did not show mutagenic activity in Ames/Salmonella and Z. mays MI test systems. Furthermore, some extracts showed significant antimutagenic activity against 9-AA in Ames test system. Inhibition rates for 9-AA mutagenicity ranged from 25.51 % (P. furfuracea – 0.05 μg/plate) to 66.14 % (C. islandica – 0.05 μg/plate). In addition, all of the extracts showed significant antimutagenic activity against sodium azide (NaN₃) mutagenicity on MI values of Z. mays.Целью работы было изучить мутагенный и антимутагенный потенциал метанольных экстрактов Cetraria islandica (L.) Ach. (Parmeliaceae), Pseudevernia furfuracea (L.) Zopf (Parmeliaceae) и Xanthoparmelia somloënsis (Gyeln.) Hale (Parmeliaceae) – лишайников из восточной части Турции. Ни один из экстрактов не показал мутагенной активности в тестах Эймса и Z. mays MI. Более того, некоторые экстракты проявляли заметную антимутагенную активность против 9-амино-акридина в тесте Эймса. Уровень ингибирования варьировал от 25,51 % (P. furfuracea) до 66,14 % (C. islandica). Кроме того, все экстракты проявляли значительную антимутагенную активность против азида натрия в Z. mays MI тесте. Все экстракты могут считаться генотоксично безопасными в исследованных концентрациях
The City of Collective Melancholy: Revisiting Pamuk’s Istanbul
This essay looks back upon Orhan Pamuk’s non-fiction book, Istanbul: Memories of a City (2003), and unpacks its multi-layered representation of the city as landscape. It is here that Pamuk pursues most overtly “the quest for the melancholic soul of his native city” which won him the 2006 Nobel Prize for Literature. Weaving personal memoir and historical essay into a unique narrative tapestry, Pamuk’s book explores a series of tensions that define the city’s image and identity; insider/outsider and East/West polarities, in particular, are tirelessly deconstructed. The essay examines Pamuk’s poetics and politics of memory in relation to works by other authors, notably Walter Benjamin. In conclusion, the new edition of Istanbul (2015) is discussed against the background of the social and spatial changes that have beset Turkey’s cultural capital in the interim
Past and future of a century old Citrus tristeza virus collection: a California citrus germplasm tale.
Citrus tristeza virus (CTV) isolates collected from citrus germplasm, dooryard and field trees in California from 1914 have been maintained in planta under quarantine in the Citrus Clonal Protection Program (CCPP), Riverside, California. This collection, therefore, represents populations of CTV isolates obtained over time and space in California. To determine CTV genetic diversity in this context, genotypes of CTV isolates from the CCPP collection were characterized using multiple molecular markers (MMM). Genotypes T30, VT, and T36 were found at high frequencies with T30 and T30+VT genotypes being the most abundant. The MMM analysis did not identify T3 and B165/T68 genotypes; however, biological and phylogenetic analysis suggested some relationships of CCPP CTV isolates with these two genotypes. Phylogenetic analysis of the CTV coat protein (CP) gene sequences classified the tested isolates into seven distinct clades. Five clades were in association with the standard CTV genotypes T30, T36, T3, VT, and B165/T68. The remaining two identified clades were not related to any standard CTV genotypes. Spatiotemporal analysis indicated a trend of reduced genotype and phylogenetic diversity as well as virulence from southern California (SC) at early (1907-1957) in comparison to that of central California (CC) isolates collected from later (1957-2009) time periods. CTV biological characterization also indicated a reduced number and less virulent stem pitting (SP) CTV isolates compared to seedling yellows isolates introduced to California. This data provides a historical insight of the introduction, movement, and genetic diversity of CTV in California and provides genetic and biological information useful for CTV quarantine, eradication, and disease management strategies such as CTV-SP cross protection
Effect of Government Expenditure on GDP in the Turkish Economy
The objective of this article is to investigate the effect of government expenditure on
GDP in Turkey from 2000Q1-2015Q4 by the superexogeneity test. As a consequence of
satisfying both conditions of weak exogeneity and structural invariance, government
expenditure is super exogenous to GDP which implies that the policy regime shift for the
period of the Global Financial Crisis in Turkey did not cause structural variance in
government expenditure. Indeed, the Lucas Critique which indicates that policy regime
shifts cause structural breaks, appears to be refuted
3d transition metal doping of semiconducting boron carbides
The introduction metallocenes, in particular ferrocene (Fe(η5-C5H5)2), cobaltocene (Co(η5-C5H5)2), and nickelocene (Ni(η5-C5H5)2), together with the carborane source molecule closo-1,2-dicarbadodecaborane, during plasma enhanced chemical vapor deposition, will result in the transition metal doping of semiconducting boron carbides. Here we report using ferrocene to introduce Fe dop¬ants, and a semiconducting boron-carbide homojunction has been fabricated. The diode characteristics are very similar to those fabricated with Co and Ni doping
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