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Institution

Bulgarian Academy of Sciences

GovernmentSofia, Bulgaria
About: Bulgarian Academy of Sciences is a government organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Coupling constant & Catalysis. The organization has 17989 authors who have published 36276 publications receiving 642820 citations. The organization is also known as: Bulgarian Academy of Sciences,簡稱:BAS & Balgarska Akademiya na Naukite.


Papers
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Journal ArticleDOI
TL;DR: A series of highly fluorescent 1,8-naphthalimide derivatives having an N-allylamino group at position 4 of the aromatic structure have been synthesized, and some of their properties for application in liquid crystal displays have been determined.
Abstract: A series of highly fluorescent 1,8-naphthalimide derivatives having an N-allylamino group at position 4 of the aromatic structure have been synthesised, and some of their properties for application in liquid crystal displays have been determined. The optical properties of the new substances are studied both in organic solvents and in the nematic liquid crystal ZLI 1840. The utility of the dyes for colouring liquid crystal displays of the 'guest–host' type is discussed on the basis of their spectral properties (absorption and emission) and the effect that the dyes have upon the orientation order parameter 〈P2〉 and upon the phase-transition behaviour of the liquid crystal in surface-stabilised display cells.

179 citations

Journal ArticleDOI
14 Feb 2011-PLOS ONE
TL;DR: Results demonstrate the suitability of oscillating-tDCS as a tool to analyze functions of endogenous EEG rhythms and underlying endogenous electric fields as well as the interactions between EEG rhythms of different frequencies.
Abstract: Previously the application of a weak electric anodal current oscillating with a frequency of the sleep slow oscillation (∼075 Hz) during non-rapid eye movement sleep (NonREM) sleep boosted endogenous slow oscillation activity and enhanced sleep-associated memory consolidation The slow oscillations occurring during NonREM sleep and theta oscillations present during REM sleep have been considered of critical relevance for memory formation Here transcranial direct current stimulation (tDCS) oscillating at 5 Hz, ie, within the theta frequency range (theta-tDCS) is applied during NonREM and REM sleep Theta-tDCS during NonREM sleep produced a global decrease in slow oscillatory activity conjoint with a local reduction of frontal slow EEG spindle power (8–12 Hz) and a decrement in consolidation of declarative memory, underlining the relevance of these cortical oscillations for sleep-dependent memory consolidation In contrast, during REM sleep theta-tDCS appears to increase global gamma (25–45 Hz) activity, indicating a clear brain state-dependency of theta-tDCS More generally, results demonstrate the suitability of oscillating-tDCS as a tool to analyze functions of endogenous EEG rhythms and underlying endogenous electric fields as well as the interactions between EEG rhythms of different frequencies

179 citations

Journal ArticleDOI
TL;DR: It is found that generalized gradient approximations (GGAs) and the B3LYP hybrid functional provide geometries in good agreement with experiment and with CASSCF calculations provided sufficiently extended basis sets are used.
Abstract: A comparison of density functionals is made for the calculation of energy and geometry differences for the high- [(5)T(2g): (t(2g))(4)(e(g))(2)] and low- [(1)A(1g): (t(2g))(6)(e(g))(0)] spin states of the hexaquoferrous cation [Fe(H(2)O)(6)](2+). Since very little experimental results are available (except for crystal structures involving the cation in its high-spin state), the primary comparison is with our own complete active-space self-consistent field (CASSCF), second-order perturbation theory-corrected complete active-space self-consistent field (CASPT2), and spectroscopy-oriented configuration interaction (SORCI) calculations. We find that generalized gradient approximations (GGAs) and the B3LYP hybrid functional provide geometries in good agreement with experiment and with our CASSCF calculations provided sufficiently extended basis sets are used (i.e., polarization functions on the iron and polarization and diffuse functions on the water molecules). In contrast, CASPT2 calculations of the low-spin-high-spin energy difference DeltaE(LH)=E(LS)-E(HS) appear to be significantly overestimated due to basis set limitations in the sense that the energy difference of the atomic asymptotes ((5)D-->(1)I excitation of Fe(2+)) are overestimated by about 3000 cm(-1). An empirical shift of the molecular DeltaE(LH) based upon atomic calculations provides a best estimate of 12 000-13 000 cm(-1). Our unshifted SORCI result is 13 300 cm(-1), consistent with previous comparisons between SORCI and experimental excitation energies which suggest that no such empirical shift is needed in conjunction with this method. In contrast, after estimation of incomplete basis set effects, GGAs with one exception underestimate this value by 3000-4000 cm(-1) while the B3LYP functional underestimates it by only about 1000 cm(-1). The exception is the GGA functional RPBE which appears to perform as well as or better than the B3LYP functional for the properties studied here. In order to obtain a best estimate of the molecular DeltaE(LH) within the context of density functional theory (DFT) calculations we have also performed atomic excitation energy calculations using the multiplet sum method. These atomic DFT calculations suggest that no empirical correction is needed for the DFT calculations.

178 citations

Journal ArticleDOI
TL;DR: SEM observations showed that hybrid mats were very effective in suppressing the adhesion of pathogenic bacteria S. aureus and E. coli and are promising for wound-healing applications.
Abstract: Continuous defect-free nanofibers containing chitosan (Ch) or quaternized chitosan (QCh) were successfully prepared by one-step electrospinning of Ch or QCh solutions mixed with poly[(L-lactide)-co-(D,L-lactide)] in common solvent. XPS revealed the surface chemical composition of the bicomponent electrospun mats. Crosslinked Ch- and QCh-containing nanofibers exhibited higher kill rates against bacteria S. aureus and E. coli than the corresponding solvent-cast films. SEM observations showed that hybrid mats were very effective in suppressing the adhesion of pathogenic bacteria S. aureus. The hybrid nanofibers are promising for wound-healing applications.

177 citations

Journal ArticleDOI
TL;DR: Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from EUCalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucallyptigena from EucalyPTus brassiana, Myrtapenidiella gaelicola eucaliptorum from Eukalyptu pellitas, Pilidiellarina euc
Abstract: Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucalyptigena from Eucalyptus brassiana, Myrtapenidiella eucalyptorum from Eucalyptus pellita, Pilidiella eucalyptigena from Eucalyptus brassiana and Strelitziana malaysiana from Acacia mangium. Furthermore, Stachybotrys sansevieriicola is described from Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria trifasciata, Elsinoe othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae fam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia), Hormonema viticola from Vitis vinifera (Canary Islands), Chlorophyllum pseudoglobossum from a grassland (India), Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus (Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora viticola from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aurantiorugosus from soil (Vietnam), Rhizopogon granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus (Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from Theobroma cacao (Ecuador). Myrmecridium iridis (Myrmecridiales ord. nov., Myrmecridiaceae fam. nov.) is also described from Iris sp. (The Netherlands). Novel genera include (Ascomycetes): Budhanggurabania from Cynodon dactylon (Australia), Soloacrosporiella, Xenocamarosporium, Neostrelitziana and Castanediella from Acacia mangium and Sabahriopsis from Eucalyptus brassiana (Malaysia), Readerielliopsis from basidiomata of Fuscoporia wahlbergii (French Guyana), Neoplatysporoides from Aloe ferox (Tanzania), Wojnowiciella, Chrysofolia and Neoeriomycopsis from Eucalyptus (Colombia), Neophaeomoniella from Eucalyptus globulus (USA), Pseudophaeomoniella from Olea europaea (Italy), Paraphaeomoniella from Encephalartos altensteinii, Aequabiliella, Celerioriella and Minutiella from Prunus (South Africa). Tephrocybella (Basidiomycetes) represents a novel genus from wood (Italy). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

177 citations


Authors

Showing all 18074 results

NameH-indexPapersCitations
Dimitri Bourilkov134148996884
Eduardo De Moraes Gregores133145492464
Georgi Sultanov132149393318
Plamen Iaydjiev131128587958
Pedro G Mercadante129133186378
Jordan Damgov129119585490
Roumyana Hadjiiska126100373091
Mircho Rodozov12497270519
Cesar Augusto Bernardes12496570889
Viktor Matveev123121273939
Ayda Beddall12081667063
Andrey Marinov11989357183
Mariana Vutova11760656698
Lester Packer11275163116
Patrick Couvreur11167856735
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202345
2022137
20211,321
20201,465
20191,284
20181,248