bluuebunny/crossref_metadata_2025 huggingface dataset:
Ambiguity in language networks
Authors: Solé Ricard V. , Seoane Luís F.
Published: January 2015

Human language defines the most complex outcomes of evolution. The emergence of such an elaborated form of communication allowed humans to create extremely structured societies and manage symbols at different levels including, among others, semantics. All linguistic levels have to deal with an astronomic combinatorial potential that stems from the recursive nature of languages. This recursiveness is indeed a key defining trait. However, not all words are equally combined nor frequent. In breaking the symmetry between less and more often used and between less and more meaning-bearing units, universal scaling laws arise. Such laws, common to all human languages, appear on different stages from word inventories to networks of interacting words. Among these seemingly universal traits exhibited by language networks, ambiguity appears to be a specially relevant component. Ambiguity is avoided in most computational approaches to language processing, and yet it seems to be a crucial element of language architecture. Here we review the evidence both from language network architecture and from theoretical reasonings based on a least effort argument. Ambiguity is shown to play an essential role in providing a source of language efficiency, and is likely to be an inevitable byproduct of network growth.
Neutrale Ultrastrahlung von der Sonne
Authors: Biermann L. , Haxel O. , Schlüter A.
Published: January 2015

Es wird gezeigt, daß bei der Beschleunigung geladener Teilchen in den äußeren Teilen der Sonnenatmosphäre durch Kerntreffer von auf die Sonne zurückfliegenden Partikeln Neutronen erzeugt werden können. Obwohl die Ausbeute (Zahl der die Sonne verlassenden Neutronen / Zahl der beschleunigten geladenen Teilchen) von der Ordnung 10-2 sein mag, kann der Effekt merklich sein, da auch geladene Teilchen einer Energie unterhalb der Abschneideenergie des Erdmagnetfeldes zur Neutronenproduktion beitragen.
Wasserstoff bei hohen Temperaturen
Authors: Bredt Irene
Published: January 2015

Es werden zunädist spezifische Wärmen, Enthalpien, Dissoziations-, Ionisationsgrade und Entropien von Wasserstoff zwischen 1000 und 10 000° K, bei Drucken zwischen 10-3 und 10+6 atm berechnet und graphisch dargestellt, - in der Absicht, die Eigenschaften von Wasserstoff als Arbeitsmedium in Wärmekraftmaschinen hoher Temperaturen quantitativ zu untersuchen.

Im zweiten Teil der Arbeit wird dann die freiwerdende mechanische Energie bei adiabatischen Entspannungsvorgängen berechnet, unter der Voraussetzung, daß der Wasserstoff im Kessel durch Zufuhr einer nicht näher definierten „Aufheizungsenthalpie" auf beliebige Temperaturen erhitzt werden kann. Für Kesselzustand und Gaszustand am Ende der Entspannungsdüse werden verschiedene theoretisch vorstellbare Grenzfälle der Gleichgewichtseinstellung berücksichtigt:

1. Vollkommene Gleichgewichtseinstellung überall, entsprechend den zu Beginn der Untersuchung dargestellten Zustandsberechnungen.

2. Einfrieren eines oder mehrerer Freiheitsgrade, die zur Anpassung an das allgemeine Gleichgewichtsniveau längere Zeiten benötigen, als sie durch die Aufenthaltsdauern in Kessel und Düse zur Verfügung stehen könnten.

Zusammenfassend werden die bei den verschiedenen Entspannungsfällen gewinnbaren Ausströmgeschwindigkeiten des Wasserstoffs in Abhängigkeit von der aufgewendeten Aufheizungsenthalpie graphisch dargestellt.
Flammenspektren von Systemen mit NO2 -gebundenem Sauerstoff
Authors: Behrens Hans , Rössle Fritz
Published: January 2015

Es werden die Flammenspektren der Normaldruckverbrennung der Systeme Leuchtgas-NO, Benzol-NO, Benzol-Tetranitromethan sowie eines Böhrenpulvers wiedergegeben. Charakteristisch für diese Systeme im Unterschied zu Systemen mit Sauerstoffverbrennung sind das Fehlen der C2-Banden und das Auftreten zweier NH-Banden bei 3240 Å sowie der 4. positiven Gruppe der CO-Banden. Die Befunde lassen sich auf Grund der leichten Reaktion des NO mit Radikalen verstehen gemäß

C2 + NO = CO + CN

CH + NO = CO + NH,

wobei die Reaktionswärmen zur Anregung des CO und NH mit anschließender Ausstrahlung der beobachteten Banden dienen (Chemilumineszenz). Aus der Ähnlichkeit der Spektren wird geschlossen, daß für alle Treibmittel mit NO2-gebundenem Sauerstoff (Pulver, Systeme mit C(NO2)4 oder HNO3 als Sauerstoffträger) die formulierten Reaktionen beim Verbrennungsvorgang mitwirken.
Über die Gültigkeit des Lambertschen und des Beerschen Gesetzes
Authors: Luck Werner
Published: January 2015

Die Gültigkeitsbereiche des Lambertschen und des Beerschen Absorptionsgesetzes werden untersucht. Die Berechnungen der Gesamtabsorption überlappender Spektrallinien werden erweitert und in einer allgemein anwendbaren Form angegeben. Mit diesen Rechnungen kann unter anderem auch der Übergang eines Viellinienspektrums in ein Kontinuum beschrieben werden.
Durch Dehnung bewirkter Vorzeichenwechsel der Magnetostriktion II
Authors: Elsas A. , Vogt E.
Published: January 2015

In Teil A werden Ergebnisse von Messungen der Magnetostriktion an einer Heusler-Legie-rung, an Fe-Ni-Legierungen und an Ni mitgeteilt. Auch wurde versucht, durch geeignete Versudisführung zu reversiblen (∂J/∂σ)H zu gelangen. Deren Vergleich mit den gemessenen (∂λ/∂H) ermöglicht Aussagen über den Anteil an reversiblen und irreversiblen 90°-und 180°-Wandverschiebungen an verschiedenen Stellen der Magnetisierungskurve.

Bei gewissen Fe-Ni-Legierungen wird die Magnetostriktion (MS) unter hoher Zugspannung negativ, obgleich die Einkristalle in allen Richtungen positive MS besitzen. In Teil B wird gezeigt, daß bei ihnen die sehr große Anisotropie der MS diesen Vorzeichenwechsel erklären kann. Berechnungen nach Ansätzen von Becker und Döring führen zu guter Übereinstimmung mit den Meßwerten. Bei geringerer Anisotropie bleibt nach Messung und Rechnung der Vorzeichenwedasel aus. A.
Untersuchungen über die Ausbreitung von Raumwellen II
Authors: Budde Walter
Published: January 2015

Bei der Bestimmung der Ausbreitungsrichtung von Kurzwellen treten kurzzeitige Schwankungen der Azimutanzeige auf. In den ersten Morgenstunden sind im allgemeinen die Schwankungen ziemlich groß, nehmen jedoch im Laufe des Morgens ab und durchlaufen während der Mittagszeit ein Minimum. Dann nehmen die Schwankungen wieder zu, erreichen während des Nachmittags ein Maximum, um in den späten Nachmittag-und frühen Abendstunden wieder abzusinken. Ein jahreszeitlicher Gang der mittleren Schwankung läßt sich für die Monate Oktober bis Januar nicht erkennen.
Über die strahlungslosen Übergänge in Sulfidphosphoren
Authors: Schön Michael
Published: January 2015

Die strahlungslosen Übergänge in den Grundzustand im Kristallgitter eines Phosphors mit Rekombinationsleuchten werden im Bändermodell Übergängen aus den Haftstellen ins Valenzband zugeordnet und die stationären Lösungen untersucht. In sehr guter Näherung läßt sidi das Gleidaungssystem mit Hilfe der Neutralitätsbedingung lösen. Die Ergebnisse werden mit-geteilt: Bei schwacher Anregung tragen nur tiefe Haftstellen (Abstand zum Leitfähigkeitsband größer als Abstand der Aktivatorterme vom Valenzband) zu den strahlungslosen Übergängen bei. Die Ausbeute ist dann sehr klein und bei sehr schwacher Anregung konstant. Wenn die Konzentration der tiefen Haftstellen kleiner ist als die der Aktivatoren (Bedingung für die Lumineszenz), wird bei zunehmender Anregung ein Bereich der Haftstellensättigung durchlaufen, in dem die Ausbeute sprunghaft zunimmt. In diesem Bereich ist die Zahl der strahlungslosen Übergänge proportional dem Quadrat der Konzentration der tiefen Haftstellen. Nach dem Überschreiten des Bereichs der Haftstellensättigung nimmt die Ausbeute noch zu, bis etwa die Hälfte der Aktivatoren angeregt ist. Dann nimmt sie infolge der mit der beginnenden Sättigung der Aktivatoren stärkeren Zunahme der Löcherkonzentration ab. Bei extrem starken Anregungen wird eine konstante Grenzausbeute erreicht. Die Killer sind als Haftstellen aufzufassen.
Zur phänomenologischen Theorie der Supraleitung
Authors: Koppe H.
Published: January 2015

Es wird darauf hingewiesen, daß die Abhängigkeit der Londonschen Konstante λ von der Temperatur zu sehr unplausiblen Aussagen über die Entropie eines Supraleiters im Magnetfeld führt. Zur Beseitigung dieser Schwierigkeiten wird eine Abänderung der Londonschen Theorie vorgeschlagen, bei der λ eine Veränderliche ist, die sich auf einen thermodynamischen Gleichgewichtswert einstellt. Es zeigt sich, daß man so zu einer nichtlinearen Verallgemeinerung der Londonschen Theorie geführt wird.
Evaluation of the Anticonvulsant Activity of Terpinen-4-ol
Authors: Sousa Damião P. de , Nóbrega Franklin F. F. , Morais Liana C. S. L. de , Almeida Reinaldo N. de
Published: January 2015

Terpinen-4-ol is a monoterpenoid alcohol and component of the essential oils of several aromatic plants. Similarly to terpinen-4-ol, other monoterpenoid alcohols have shown anticonvulsant activity in convulsion animal models. The present study aimed to investigate the anticonvulsant activity of terpinen-4-ol. Treatment of mice with terpinen-4-ol ( 200 mg/kg) caused a signifi cant decrease in the spontaneous motor activity at 30, 60 and 120 min after administration. Terpinen-4-ol (100 and 200 mg/kg) produced a significant dosedependent increase in the duration of sleeping in mice. Pretreatment of mice with terpinen-4- ol at doses of 100, 200 and 300 mg/kg significantly increased the latency of pentylenetetrazole -induced convulsions. Terpinen-4-ol (200 and 300 mg/kg) also inhibited the induced seizures of picrotoxin. In another model, maximal electroshock seizure, terpinen-4-ol decreased the tonic hind convulsions percentage at the dose of 300 mg/kg. From the overall results we can conclude that terpinen-4-ol showed a depressant effect on the central nervous system and significant anticonvulsant activity.
Antibacterial Activity and Essential Oil Composition of Satureja spicigera from Iran
Authors: Eftekhar Fereshteh , Raei Fereshteh , Yousefzadi Morteza , Ebrahimi Samad Nejad , Hadian Javad
Published: January 2015

The aerial parts of Satureja spicigera were collected at full flowering stage at Gazvin, Iran. The essential oil was isolated by hydrodistillation and analyzed by a combination of capillary GC and GC-MS. Fourteen compounds were identified, of which carvacrol (53.74%) and thymol (36.03%) were the main constituents, representing 99.12% of the total oil. The in vitro antibacterial activity of the essential oil was determined against six ATCC standard bacterial strains (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) using disc diffusion as well as measurement of minimum inhibitory concentrations. The disc diffusion results and MIC values indicated high inhibitory activity against the test bacteria. The most susceptible organisms were the Gram-positive B. subtilis and S. aureus followed by E. faecalis, usually resistant to most common antibiotics. Among the Gram-negative bacteria, E. coli and K. pneumoniae were highly sensitive to the different oil concentrations in the disc diffusion method. Finally, P. aeruginosa, a highly resistant organism to most antibiotics, showed moderate susceptibility to Satureja spicigera essential oil.
Evaluation of Different Carbon Sources for Growth and Biosurfactant Production by Pseudomonas fluorescens Isolated from Wastewaters
Authors: Stoimenova Emilia , Vasileva-Tonkova Evgenia , Sotirova Anna , Galabova Danka , Lalchev Zdravko
Published: January 2015

The indigenous strain Pseudomonas fluorescens, isolated from industrial wastewater, was able to produce glycolipid biosurfactants from a variety of carbon sources, including hydrophilic compounds, hydrocarbons, mineral oils, and vegetable oils. Hexadecane, mineral oils, vegetable oils, and glycerol were preferred carbon sources for growth and biosurfactant production by the strain. Biosurfactant production was detected by measuring the surface and interfacial tension, rhamnose concentration and emulsifying activity. The surface tension of supernatants varied from 28.4 mN m-1 with phenanthrene to 49.6 mN m-1 with naphthalene and heptane as carbon sources. The interfacial tension has changed in a narrow interval between 6.4 and 7.6 mN m-1. The emulsifying activity was determined to be highest in media with vegetable oils as substrates. The biosurfactant production on insoluble carbon sources contributed to a signifi cant increase of cell hydrophobicity and correlated with an increased growth of the strain on these substrates. Based on these results, a mechanism of biosurfactant-enhanced interfacial uptake of hydrophobic substrates could be proposed as predominant for the strain. With hexadecane as a carbon source, the pH value of 7.0 - 7.2 and temperature of (28 ± 2) °C were optimum for growth and biosurfactant production by P. fluorescens cells. The increased specific protein and biosurfactant release during growth of the strain on hexadecane in the presence of NaCl at contents up to 2% could be due to increased cell permeability. The capability of P. fluorescens strain HW-6 to adapt its own metabolism to use different nutrients as energy sources and to keep up relatively high biosurfactant levels in the medium during the stationary phase is a promising feature for its possible application in biological treatments.
Action Spectra of Chlorophyll a Biosynthesis in Cyanobacteria: Dark-Operative Protochlorophyllide Oxidoreductase-Deficient Mutants
Authors: Gao Yang , Xiong Wei , He Ming J. , Tang Li , Xiang Jin Y. , Wu Qing Y.
Published: January 2015

Both light-dependent and light-independent (dark) protochlorophyllide (Pchlide) reductase account for catalyzing the reduction of Pchlide to chlorophyllide during the biosynthesis of Mg-tetrapyrrole pigments in cyanobacteria. To gain more insight into the interaction between the wavelength of the light and these two chlorophyll synthetic pathways in Synechocystis sp. PCC 6803, the spectral effectiveness of the formation of chlorophyll a was investigated during the regreening process in chlL- and chlN- mutants, which could not synthesize chlorophyll during growth in the dark. The action spectra showed obvious maxima around 450 nm and 650 nm, similar to those of higher plants except that the intensities of two peaks are reversed. The mRNA levels of chlL and chlN and chlorophyll a content under different wavelengths of light in the wild-type strain were also measured. The RT-PCR analysis revealed that the transcripts of chlL and chlN were up-regulated in red light but simultaneously down-regulated in green light which resulted in corresponding changes of the chlorophyll content. This fact indicates that the regulation of dark-operative protochlorophyllide oxidoreductase (DPOR) in the transcriptional level is essential for cyanobacteria to synthesize appropriate chlorophyll for acclimating in various light colour environments.
Anti-Hepatitis B Virus Activity of New Substituted Pyrimidine Acyclic Nucleoside Analogues
Authors: Abdel-Rahman Adel A.-H. , Zeid Ibrahim F. , Barakat Hussien A. , El-Sayed Wael A.
Published: January 2015

A number of N-substituted pyrimidine acyclic nucleosides were synthesized by coupling reaction of 2-(2-chloroethoxy)ethyl acetate or (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 4-methylbenzenesulfonate with the corresponding base followed by deprotection. The synthesized compounds were tested for their antiviral activity against hepatitis B virus (HBV). The plaque reduction infectivity assay was used to determine virus count reduction as a result of treatment with the synthesized compounds which showed moderate to high antiviral activities
Anti-HIV Activity of New Substituted 1,3,4-Oxadiazole Derivatives and their Acyclic Nucleoside Analogues
Authors: El-Sayed Wael A. , El-Essawy Farag A. , Ali Omar M. , Nasr Barsis S. , Abdalla Mohamed M. , Abdel-Rahman Adel A.-H.
Published: January 2015

A number of new 5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazole derivatives, 2 - 5 and 8 - 11, were synthesized. The 2-{5-[(naphthalen-5-yloxy)methyl]-1,3,4-oxadiazol-2-ylthio}acetohydrazones 6a and 6b were synthesized by the reaction of the hydrazide 4 with the corresponding monosaccharides. Cyclization of the sugar hydrazones 6a and 6b with acetic anhydride afforded the substituted oxadiazoline derivatives 7a and 7b. The synthesized compounds were evaluated for their antiviral activity against, the human immunodefi ciency virus (HIV-1) and some of these compounds showed moderate to high antiviral activity.
Evaluation of Antinociceptive and Anti-Inflammatory Activities of a New Triterpene Saponin from Bauhinia variegata Leaves
Authors: Mohamed Mona A. , Mammoud Madeha R. , Hayen Heiko
Published: January 2015

A new triterpene saponin, named as 23-hydroxy-3α-[O-α-L-1C4-rhamnopyranosyl-(1´´4´)- O-α-L-4C1-arabinopyranosyl-oxy]olean-12-en-28-oic acid O-α-L-1C4-rhamnopyranosyl- (1´´´´´→4´´´´)-O-β-D-4C1-glucopyranosyl-(1´´´´→6´´´)-O-β-D-4C1-glucopyranosyl ester (9), was isolated from the leaves of Bauhinia variegata Linn. In addition, six flavonoid compounds along with two cinnamic acid derivatives were isolated and identified based on their chromatographic properties, and chemical and spectral data (ESI-high resolution-MSn, 1H NMR, 13C NMR, 1H-1H COSY, HSQC, and HMBC). Compound 9 was found to be nontoxic (LD50) and to have significant anti-inflammatory and antinociceptive activities. It also showed a slight antischistosomal activity.
Bioactive Metabolites Produced by Penicillium sp.1 and sp.2, Two Endophytes Associated with Alibertia macrophylla (Rubiaceae)
Authors: Oliveira Camila M. , Silva Geraldo H. , Regasini Luis O. , Zanardi Lisinéia M. , Evangelista Alana H. , Young Maria C. M. , Bolzani Vanderlan S. , Araujo Angela R.
Published: January 2015

In the course of our continuous search for bioactive metabolites from endophytic fungi living in plants from the Brazilian fl ora, leaves of Alibertia macrophylla (Rubiaceae) were submitted to isolation of endophytes, and two species of Penicillium were isolated. The acetonitrile fraction obtained in corn from a culture of Penicillium sp.1 afforded orcinol (1). On the other hand, Penicillium sp.1 cultivated in potato-dextrose-broth furnished two different compounds, cyclo-(L-Pro-L-Val) (2) and uracil (3). The chromatographic fractionation of the acetonitrile fraction obtained from Penicillium sp.2 led to three dihydroisocoumarins, 4-hydroxymellein (4), 8-methoxymellein (5) and 5-hydroxymellein (6). Compounds 5 and 6 were obtained from the Penicillium genus for the fi rst time. Additionally, metabolites 1 - 6 were evaluated for their antifungal and acetylcholinesterase (AChE) inhibitory activities. The most active compounds 1 and 4 exhibited detection limits of 5.00 and 10.0 μg against Cladosporium cladosporioides and C. sphaerospermum, respectively. Compound 2 showed a detection limit of 10.0 μg, displaying potent AChE inhibitory activity.
Molecular and Phylogenetic Analysis of Pyridoxal Phosphate- Dependent Acyltransferase of Exiguobacterium acetylicum
Authors: Rajendran Narayanan , Smith Colby , Mazhawidza Williard
Published: January 2015

The pyridoxal-5’-phosphate (PLP)-dependent family of enzymes is a very diverse group of proteins that metabolize small molecules like amino acids and sugars, and synthesize cofactors for other metabolic pathways through transamination, decarboxylation, racemization, and substitution reactions. In this study we employed degenerated primer-based PCR amplification, using genomic DNA isolated from the soil bacterium Exiguobacterium acetylicum strain SN as template. We revealed the presence of a PLP-dependent family of enzymes, such as PLP-dependent acyltransferase, and similarity to 8-amino-7-oxononoate synthase. Sequencing analysis and multiple alignment of the thymidine-adenine-cloned PCR amplicon revealed PLP-dependent family enzymes with specific confering codes and consensus amino acid residues specific to this group of functional proteins. Amino acid residues common to the majority of PLP-dependent enzymes were also revealed by the Lasergene MegAlign software. A phylogenetic tree was constructed. Its analysis revealed a close relationship of E. acetylicum to other bacteria isolated from extreme environments suggesting similarities in anabolic adaptability and evolutionary development.
In vitro Antioxidant Capacities of Two Benzonaphthoxanthenones: Ohioensins F and G, Isolated from the Antarctic Moss Polytrichastrum alpinum
Authors: Bhattarai Hari Datta , Paudel Babita , Lee Hong Kum , Oh Hyuncheol , Yim Joung Han
Published: January 2015

Antioxidant agents against reactive oxygen species can be used for several cosmetic and medicinal applications. This study’s objective was to evaluate the antioxidant activities of Polytrichastrum alpinum (Hedw.) G. L. Sm. (Polytrichaceae), an Antarctic moss species collected from King George Island (Antarctica). The identifi cation of the moss species was performed on the basis of morphological characteristics and molecular sequencing of the 18S rRNA gene. Two benzonaphthoxanthenones: ohioensins F and G, were isolated from the extract after several chromatographic procedures. The various in vitro antioxidant capacities of a methanolic extract of P. alpinum and the isolated compounds were evaluated by analyzing the scavenging capacities of free radicals of 2,2-azino-bis(3-ethylbenzthiazoline- 6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), the total phenol assay with Folin-Ciocalteu reagent, the ferric ion (Fe3+) reducing power and the nitric oxide (NO) scavenging activity and compared to those of commercial standards for each assay. The experimental data showed that even the crude extract of P. alpinum exhibited potent antioxidant activity. The antioxidant activity was increased two- to seven-fold for the purified compounds. The antioxidant activities of both purified compounds were found to be more or less the same in all experiments. However, the obtained data showed that the Fe3+ reducing power of the purified compounds and crude methanolic extract was almost the same suggesting the presence of other stronger reducing agents in the methanolic extract which could not be isolated in the present experiment. Therefore, further work on the isolation of these stronger antioxidant agents from this moss specimen of the extreme environment is warranted. Developments of laboratory mass culture techniques are anticipated to achieve bulk production of the active constituents for commercial application.
Antimalarial Compounds from the Stem Bark of Vismia laurentii
Authors: Noungoue Diderot T. , Chaabi Mehdi , Ngouela Silvère , Antheaume Cyril , Boyom Fabrice F. , Gut Jiri , Rosenthal Philip J. , Lobstein Annelise , Tsamo Etienne
Published: January 2015

A phytochemical study of the stem bark of Vismia laurentii resulted in the isolation of a tetracyclic triterpene, tirucalla-7,24-dien-3-one (1), and seven other known compounds: 3-geranyloxyemodin (2), vismiaquinone A (3), vismiaquinone B (4), bivismiaquinone (5), epifriedelinol (6), betulinic acid (7) and stigmasta-7,22-dien-3-ol (8). The structure of all these compounds was elucidated by spectroscopic means. The stem bark extract and compounds 1 and 3 showed good antimalarial activity against the W2 strain of Plasmodium falciparum.
Depth-Related Alkaloid Variation in Mediterranean Aplysina Sponges
Authors: Putz Annika , Kloeppel Anne , Pfannkuchen Martin , Brümmer Franz , Proksch Peter
Published: January 2015

Total amounts and patterns of bromoisoxazoline alkaloids of Aplysina sponges from Croatia (Mediterranean Sea) were analyzed along an underwater slope ranging from 1.8 to 38.5 m. Total amounts of alkaloids varied from sample to sample and showed no correlation with depth. In contrast, striking differences of alkaloid patterns were found between sponges from shallow sites (1.8 - 11.8 m) and those collected from deeper sites (11.8 - 38.5 m). Sponges from shallow depths consistently exhibited alkaloid patterns typical for Aplysina aerophoba with aerophobin-2 (2) and isofistularin-3 (3) as main constituents. Sponges from deeper sites (below 11.8 m) resembled Aplysina cavernicola with aerothionin (4) and aplysinamisin- 1 (1) as major compounds. The typical A. cavernicola pigment 3,4-dihydroxyquinoline- 2-carboxylic acid (6), however, could not be detected in A. aerophoba sponges but was replaced by the A. aerophoba pigment uranidine (5) which appeared to be present in all sponge samples analyzed. During transplantation experiments sponges from sites below 30 m featuring the A. cavernicola chemotype of bromoisoxazoline alkaloids were translocated to shallower habitats (10 m). The alkaloid patterns in transplanted sponges were found to be stable over a period of 12 months and unaffected by this change in depth. In a further experiment, clones of Aplysina sponges from shallow depths of 5 - 6 m resembling the A. aerophoba chemotype were either kept in situ under natural light conditions or artificially shaded by excluding photosynthetically active radiation (PAR). Neither 4 nor 1 were detected in artificially shaded sponges over an observation period of 12 months. In summary, two chemically distinct types of Aplysina sponges were discovered in this study that proved to be remarkably stable with regard to the bromoisoxazoline patterns and unaffected either by changing the light conditions or depth. It is not clear presently whether the Aplysina sponges collected from depths < 11.8 m represent a new chemotype of A. cavernicola lacking the pigment 6 or whether we have incidentally come across a so far undescribed species of the genus Aplysina.
Alkaloids from Sternbergia colchiciflora
Authors: Berkov Strahil , Bastida Jaume , Tsvetkova Reneta , Viladomat Francesc , Codina Carles
Published: January 2015

Twenty-one alkaloids and related compounds were found in Sternbergia colchiciflora (Amaryllidaceae), a hitherto not studied plant species. Twenty of them were detected by GC-MS in the crude extracts of this plant species. Ten alkaloids were isolated and their structures confirmed by NMR, MS and CD measurements. Many of the compounds found in this species, such as lycorine, tazettine, haemanthidine, are known to possess strong bioactivity. Variations in the alkaloid pattern were found during the phenological cycle of the plant. Lycorine-type compounds were dominant in the plant organs during both the fl owering period and dormancy. The alkaloid pattern during both periods of leaf development and fructification was dominated by haemanthamine-type in the leaves and lycorine-type compounds in the bulbs, respectively
Hepatoprotective and Antioxidant Activity of Two Iridoids from Mussaenda ‘dona aurora’
Authors: Vidyalakshmi Kandulva Sethuraman , Nagarajan Sulochana , Vasanthi Hannah Rachel , Venkappaya  , Rajamanickam Victor
Published: January 2015

Mussaenda ‘dona aurora’ (sepals) has been investigated for its hepatoprotective and antioxidant activities. The highest activity was observed in the ethyl acetate fraction. The separation of the ethyl acetate fraction gave two iridoids, sanshiside-D and lamalbide. Sanshiside-D exhibited a hepatoprotective activity greater than silimarin as was evidenced by significant reduction of ALT and AST in the serum enzyme levels
The Interleukin-18 Inhibitory Activities of Echinocystic Acid and its Saponins from Impatiens pritzellii var. hupehensis
Authors: Zhou Xue-Feng , Tang Lan , Zhang Peng , Zhao Xiao-Ya , Pi Hui-Fang , Zhang Yong-Hui , Ruan Han-Li , Liu Yonghong , Wu Ji-Zhou
Published: January 2015

1

Echinocystic acid (), an echinocystic acid saponin, 2, and four of its ester saponins, 3 - 6, obtained from the active fraction of Impatiens pritzellii var. hupehensis, an traditional Chinese medicine for rheumatoid arthritis, were investigated for their effects on lipopolysaccharide (LPS)-induced interleukin (IL)-18 in human peripheral blood mononuclear cells. Three of them, 1, 2 and 6, showed obvious activity to inhibit the production of IL-18, especially the ester saponins with a sugar chain at C-28, 6. Structure-activity relationships are discussed in brief
Some Physicochemical Peculiarities of Poplar Plastocyanins a and b
Authors: Christova Petya K. , Donchev Anthony A. , Shosheva Alexandra C. , Getov Vladimir I. , Dimitrov Mitko I.
Published: January 2015

The redox potentials of poplar plastocyanins a and b (PCa, PCb) were determined by spectro photometric titrations of their reduced forms with [Fe(CN)6]3-. It was found that the two isoforms have the following millimolar extinction coefficients ε597, equilibrium constants Keq of one-electron exchange with [Fe(CN)6]4-/[Fe(CN)6]3-, and standard electron potentials E0′: PCa: ε597 = (4.72 ± 0.08) mM-1 cm-1, Keq = 0.133 ± 0.009, E0′ = (354 ± 11) mV; PCb: ε597 = (5.23 ± 0.16) mM-1 cm-1, Keq = 0.175 ± 0.010, E0′ = (363 ± 12) mV. The pH dependence of the redox potential of PCb was studied too. It was found, that the value of E0′ for PCb is constant in the pH range 6.5 - 9.5, but decreases in the range 4.8 - 6.5. On the whole, the dependence resembles that of PC from some well-known plant species, including poplar PCa. The changes of E0′ in the pH-dependent region for poplar PCb, however, are smaller and are 13 mV per pH unit, whereas in the other well-known plant species the changes are about 50 - 60 mV per pH unit. It has been assumed that the weaker pH dependence of E0′ of PCb accounts for some structural differences between PCa and PCb
Is the Concept of Photosynthetic Units Verified?
Authors: Zeinalov Yuzeir
Published: January 2015

The cornerstones of the first fundamental concept of photosynthetic machinery, i.e. the concept of photosynthetic units, are reconsidered and a new logically and experimentally well sustained interpretation of the crucial observations of this hypothesis is presented. The results obtained lead to the conclusion that under low irradiances all chlorophyll molecules are in a state to perform charge separation (photochemical) reaction, while under increased irradiances the essential part of the reaction centres are blocked and only one reaction centre from 500 - 600 remains in functionally active state, i.e. in the range of the value obtained by the founders of the widely accepted concept of photosynthetic units.
LC-MS and LC-PDA Analysis of Hypericum empetrifolium and Hypericum sinaicum
Authors: Alali Feras Q. , Tawaha Khaled , Gharaibeh Mohammad
Published: January 2015

Within the framework of our continuous efforts to explore Hypericum species from Jordan, we report the analysis of the major active metabolites, naphthodianthrones and phloroglucinols, in the methanolic extracts of two under-explored Hypericum species; H. empetrifolium Willd. and H. sinaicum Hochst. & Steud. ex Boiss., using LC-(+,-)-ESI-MS (TIC and SIM) and LC-UV/Vis spectroscopy. Based on their LC-UV/Vis profiles, retention times and (+,-)-ESI-MS (TIC and SIM) spectral data, hypericin, protohypericin and pseudohypericin were identified in both of the investigated species. In addition adhyperfirin was only detected in H. empetrifolium, while hyperforin and protopseudohypericin were only detected in H. sinaicum. This is the first report documenting the presence of hypericin, protohypericin, pseudohypericin, protopseudohypericin, and hyperforin in H. sinaicum, and adhyperfirin in H. empetrifolium.
Glucose Signaling Pathway and Growth Conditions Regulate Gene Expression in Retrotransposon Ty2
Authors: Türkel Sezai , Bayram Özgür , Arık Elif
Published: January 2015

Gene expression in the yeast retrotransposon Ty2 is regulated at transcriptional and translational levels. In this study, we have shown that the transcription of Ty2 is partially dependent on the membrane-bound glucose sensors Gpr1p and Mth1p in Saccharomyces cerevisiae. Transcription of Ty2 decreased approx. 3-fold in the gpr1, mth1 yeast mutant. Moreover, our results revealed that the transcription of Ty2 fluctuates during the growth stages of S. cerevisae. Both transcription and the frameshift rate of Ty2 rapidly dropped when the stationary stage yeast cells were inoculated into fresh medium. There was an instant activation of Ty2 transcription and a high level expression during the entire logarithmic stage of yeast growth. However, the transcription of Ty2 decreased 2-fold when the yeast cultures entered the stationary stage. The frameshift rate in Ty2 also varied depending on the growth conditions. The highest frameshift level was observed during the mid-logarithmic stage. It decreased up to 2-fold during the stationary stage. Furthermore, we have found that the frameshift rate of Ty2 diminished at least 5-fold in slowly growing yeasts. These results indicate that the transcription and the frameshift efficiency are coordinately regulated in the retrotransposon Ty2 depending on the growth conditions of S. cerevisiae.
Extraction of Trace Amount of Severely Degraded DNA
Authors: Lv Pin , Zhou Xiangshan , You Jinhua , Ye Bang-Ce , Zhang Yuanxing
Published: January 2015

DNA extraction from food is always problematic especially from highly processed samples which contain only trace amounts of severely degraded DNA fragments. In this work, to extract trace amounts of small DNA fragments of the traditional Chinese medicine (TCM) colla corii asini derived from highly processed Equus asinus skin, three strategies were compared for its authentication. With some optimizations, the modified QIAquick spin column method achieved higher DNA yield and purity in comparison with the “SDS/proteinase K” method and the “Wizard magnetic DNA purification system for food” method. Further studies showed that at least 0.4 g colla corii asini was needed to obtain enough DNA extracts for PCR-based detection by the method and only amplicons of less than 100 bp could be generated from the DNA extracts which confirmed the efficiency of the method in small DNA fragment extraction. The DNA obtained by this method was suitable to be used in PCR-based authentications.
Seasonal Variation in the Essential Oil Composition of Origanum majorana L. Cultivated in Egypt
Authors: Soliman Fathy M. , Yousif Miriam F. , Zaghloul Soumaya S. , Okba Mona M.
Published: January 2015

Z. Naturforsch. 64 c, 611 - 614 (2009); received March 1/30, 2009 The hydrodistilled essential oil content of Origanum majorana L. (Lamiaceae) ranged from 2.5 - 3% with the maximal value (3%) in spring. Analysis of the oil by GC/MS resulted in the identifi cation of 15, 15, 11, and 14 components in the oils prepared in spring, summer, autumn, and winter, respectively. The composition of the essential oils differed quantitatively and qualitatively according to the time of collection. Thymol (38.4%) and cis-sabinene hydrate (25.3%) were the major components in spring plants. Terpinen-4-ol (37.4%, 20.5%, 16.3%) was a major component in the summer, autumn and winter oils, respectively. cis- Sabinene hydrate (54.4%) was major in winter plants while terpinolene (43.1%) was the main component in autumn plants. Other components detected in lower amounts in all oil samples were sabinene and p-cymene (up to 7.4% and 13.9% in autumn), and α-terpinene (up to 13.3% in summer)
Detection of Huanglongbing (Citrus Greening) Disease by Nucleic Acid Spot Hybridization
Authors: Gopal Kuraba , Sudarsan Sundeep , Gopi Venati , Naidu Latchireddy Naram , Ramaiah Maniyaram , Sreenivasulu Yasodam , Wesley Edward
Published: January 2015

Polymerase chain reaction (PCR) amplification with primers specific to the rDNA region successfully amplified the 1160-bp DNA fragment from a Huanglongbing (HLB)-infected sweet orange sample with mottling symptoms leaves, but not from healthy sweet orange plants. The PCR product of 1160-bp was used as probe labeled with biotin for detection of the HLB pathogen in the nucleic acid spot hybridization (NASH) test. It was found that the HLB pathogen could be detected up to 1:100 dilution in HLB-infected tissue. Total DNA extracted from HLB-infected tissue was diluted 2-fold as 900 ng in TE buffer and spotted on a nitrocellulose membrane. Strong signals were observed up to 225 ng of DNA dilution, whereas a moderate signal was recorded at 112 ng. No hybridization signal was observed in the healthy samples, while strong signals were observed in the positive control
The Infl uence of Hypergravity on the Paramecium bursaria- Chlorella sp. Symbiotic Association
Authors: Bator Tomasz , Pado Ryszard
Published: January 2015

The aim of the research was to determine the influence of strong hypergravity on the Paramecium bursaria-Chlorella sp. symbiotic association, which is considered to be a model example of symbiosis between a heterotroph and an autotroph. The paramecia cells were exposed to 1073 × g, 4293 × g, and 9658 × g hypergravity for 15 min. Then they were incubated for 21 d on a standard lettuce medium. The experiments were conducted in parallel under constant white light and in the dark. The changes in the number of paramecia cells during incubation were determined. Measurements of the number of Chlorella sp. endosymbionts inside host cells were also made. The results showed that a 15-min exposure to hypergravity attenuates the subsequent growth of Paramecium bursaria in the dark, but it may stimulate the growth of paramecia under constant light. Moreover, it causes an increase in the number of algae inside the paramecia cells. Presumably, the influence of hypergravity on the studied symbiotic complex is connected with its effect on the endosymbiotic Chlorella sp. cells. This subject requires further research, focused on the influence of hypergravity on the physiology and growth of the Chlorella sp. endosymbionts living inside the Paramecium bursaria cells
Cholinesterase Inhibitory and Antioxidant Properties of Verbascum mucronatum Lam. and its Secondary Metabolites
Authors: Kahraman Cigdem , Tatlı I. Irem , Orhan Ilkay Erdogan , Akdemir Zeliha S.
Published: January 2015

1

The aqueous extract of Verbascum mucronatum Lam. along with its fractions and secondary metabolites were assessed for their antioxidant, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitory activities. The antioxidant activity was evaluated by three methods: as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion-chelating effect, and ferric-reducing antioxidant power (FRAP) tests. The AChE activity was determined by the Ellman method using an ELISA microplate reader. Phytochemical investigations revealed the presence of four iridoid glucosides, ajugol (), aucubin (2), lasianthoside I (3) and catalpol (4), two saponins, ilwensisaponin A (5) and C (6), and a phenylethanoid glycoside, verbascoside (7), in Verbascum mucronatum. Their structures were elucidated by spectral techniques. The aqueous extract and fractions including the phenylethanoid glycoside 7 showed DPPH scavenger effect and had the best FRAP. Besides these results, one of the phenylethanoid fractions displayed the highest ferrous ion-chelating effect. While only 7 was found to possess moderate AChE inhibition, the extract, fractions, and all other tested compounds did not inhibit AChE and BChE
Characterization of a Novel Long-Chain n-Alkane-Degrading Strain, Dietzia sp. E1
Authors: Bihari Zoltán , Szabó Zsolt , Szvetnik Attila , Balázs Margit , Bartos Péter , Tolmacsov Péter , Zombori Zoltán , Kiss István
Published: January 2015

The newly isolated strain E1, identified as a Dietzia sp., proved to have an excellent ability to degrade n-C12 to n-C38 alkane components of crude oil. The preferred substrate was the very long-chain alkane n-eicosane at an optimal temperature of 37 °C and an optimal pH of 8 under aerobic conditions. The growth and substrate uptake kinetics were monitored during the n-alkane fermentation process, and Dietzia sp. E1 cells were found to possess three distinct levels of cell-surface hydrophobicity. Gas chromatographic/mass spectrometric analysis revealed that intracellular substrate mineralization occurred through the conversion of n-alkane to the corresponding n-alkanal. The monoterminal oxidation pathway was presumably initiated by AlkB and CYP153 terminal alkane hydroxylases, both of their partial coding sequences were successfully detected in the genome of strain E1, a novel member of the Dietzia genus
Sequence Analysis and Expression of orf224 Gene Associated with Two Types of Cytoplasmic Male Sterility in Brassica napus L.
Authors: Liu Jianmin , Li Maoteng , Wang Hao , Yu Longjiang , Li Dianrong
Published: January 2015

Polima and Shaan 2A are the two most widely used forms of cytoplasmic male sterility (CMS) in the utilization of heterosis of rapeseed (Brassica napus) in China. A previous study indicated that the mitochondrial gene, orf224, was the only gene with a differential expression pattern among the normal, sterile and fertility-restored lines in rapeseed. DNA sequences of orf224, including coding sequences from Shaan 2A and Polima CMS, were then amplified and analyzed. DNA sequence alignment indicated both the coding sequences were 675 bp in length and had 99.9 and 99% homology in nucleotides and amino acids, respectively, and shared certain similarity to homologues from other Brassica spp. and Arabidopsis thaliana. The probable promoter regions of orf224 were conserved between B. napus and A. thaliana, but the upstream regions of probable promoter regions were completely divergent from each other. Additionally, analysis of the primary and secondary structure of the proteins encoded by orf224 from the two lines predicted that the proteins contain a α-helix, extended strand, and random coil. After cloning a in vitro experiment showed that these two proteins could be expressed in Escherichia coli BL21.
Synthesis and Antifungal Activities of Some 2,6-Bis-(Un)Substituted Phenoxymethylpyridines
Authors: Xu Hui , Qu Huan
Published: January 2015

Several 2,6-bis-(un)substituted phenoxymethylpyridines were synthesized and evaluated in vitro against Fusarium graminearum, Helminthosporium sorokinianum, Alternaria brassicae, Alternaria alternata, and Fusarium oxysporum f. sp. vasinfectum. Among all derivatives, compound 3 a exhibited a broad-spectrum antifungal activity against the five phytopathogenic fungi.
Acetylcholinesterase Inhibitory Activity of Uleine from Himatanthus lancifolius
Authors: Seidl Cláudia , Correia Beatriz L. , Stinghen Andréa E. M. , Santos Cid A. M.
Published: January 2015

Application of acetylcholinesterase (AChE) inhibitors is the primary treatment for Alzheimer’s disease. Alkaloids, such as physostigmine, galanthamine, and huperzine A, play an important role as AChE inhibitors. The aim of this work was to evaluate Himatanthus lancifolius (Muell. Arg.) Woodson, a Brazilian species of Apocynaceae, and its main indole alkaloid uleine, in order to identify new AChE inhibitors. The plant fluid extract, fractions, and uleine were tested for AChE inhibitory activity using Ellman’s colorimetric method for thin-layer chromatography (TLC), 96-well microplates, and also Marston’s TLC colorimetric method. Both TLC assays showed similar results. At 5 mg/mL, the fluid extract inhibited the AChE enzyme by (50.71 ± 8.2)%. The ethyl acetate fraction exhibited the highest level of AChE inhibition, followed by the dichloromethane fraction. The isolated alkaloid uleine displayed an IC50 value of 0.45 μM.
Hypotensive Activity of Terpenes Found in Essential Oils
Authors: Menezes Igor A. C. , Barreto Carmélia M. N. , Antoniolli Ângelo R. , Santos Márcio R. V. , Sousa Damião P. de
Published: January 2015

The cardiovascular activity of essential oils has been reported. Some studies showed that the main chemical components of these oils contribute to their pharmacological activity. Therefore, the cardiovascular activity of four monoterpenes and one sesquiterpene was evaluated in the present work. In non-anaesthetized normotensive rats, (+)-α-pinene, (-)-β-pinene, (±)-citronellol and (±)-linalool (1, 5, 10, and 20 mg/kg, i.v.) induced hypotension [maximal effect: (-35 ± 3)%, (-46 ± 4)%, (- 48 ± 2)% and (- 40 ± 2)%, respectively; n = 6] and tachycardia [maximal effect: (13 ± 4)%, (16 ± 7)%, (21 ± 1)% and (19 ± 3)%, respectively; n = 6] while (-)-α-bisabolol (1, 5, 10, and 20 mg/kg, i.v.) induced hypotension [maximal effect: (- 47 ± 8)%, n = 6] and bradycardia [maximal effect: (-57 ± 3)%]. In conclusion, these results demonstrated that all terpenes tested had hypotensive activity in rats and that the pharmacological effect of the terpene alcohols was more effective than that of the terpene hydrocarbons.
Feeding Stimulant in Cinnamomum camphora for the Common Bluebottle, Graphium sarpedon nipponum (Lepidoptera: Papilionidae)
Authors: Li Jing , Wakui Ryu , Horie Masanori , Nishimura Yoshichika , Nishiyama Yoshihide , Nishiyama Yoshihide , Ikeno Yasunori , Tebayashi Shin-ichi , Kim Chul-Sa
Published: January 2015

The acceptance of camphor tree (Cinnamomum camphora) as a host plant for the larvae of common bluebottle (Graphium sarpedon nipponum) was explained by the presence of feeding stimulants in the leaves. When the active methanol extract of C. camphora leaves was separated into hexane and water layers, both layers showed high feeding activities for the larvae of G. sarpedon nipponum. Bioassay-guided fractionation of the hexane layer resulted in the isolation of a highly active compound, which was identified as α-linolenic acid by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry.
Antimicrobial Activity of Formylchromones: Detection by a Micro-Scale Method
Authors: Lehtinen Markku , Pelttari Eila , Elo Hannu
Published: January 2015

We report the antimicrobial activity of formylchromones. These compounds are remote structural analogues of nalidixic acid and quinolone antibiotics, and their activity was investigated by a simple micro-scale method designed for the determination of minimal inhibitory concentrations (MIC) of drug candidates and antibiotics against aerobic bacteria and yeasts. Minimal bactericidal and fungicidal concentrations (MBC and MFC, respectively) were also determined in connection with the MIC determinations. The results obtained were compared with those obtained using classical agar diffusion methodology. In the MIC method, deep-well micro-titration plates are used, covered by silicone sealing mats that allow diffusion of oxygen to the wells. The appropriate broth is pipetted into the wells, followed by a standardized microbial suspension (except for sterile controls) and a dilution series of the test substance or control antibiotic or a mere control solvent. The use of white nontransparent polypropylene plates allows easy visual inspection of microbial growth. For the MBC and MFC methods, samples are taken from all wells that contain a test substance or control antibiotic and do not display growth in the MIC test. The samples are streaked on agar plates, the liquid is allowed to absorb into the agar, and finally the microbes are spread all over the plate with a bent rod. Colony counts are compared with that of the untreated microbial suspension at the beginning of the MIC test. The MIC method is suitable for high-throughput screening