bluuebunny/crossref_metadata_2025 huggingface dataset:
[2 + 1] Cycloaddition Reaction of Dialkylthioketenes with Carbenes – Isomerization of the Resulting Alkylidenethiiranes
Authors: Behr Helmut , Bolte Oliver , Dräger Gerald , Ries Monika , Schaumann Ernst
Published: June 2010

Carbenes generated by metal‐catalyzed decomposition of diazo compounds 2 undergo a smooth cycloaddition to the CS bond of thioketenes 1; products 3 were characterized by spectroscopic means as well as an X‐ray structural investigation of 3b. However, photolytic generation of diphenylcarbene from diphenylketene led to an isomeric alkylidenethiirane 4a in the reaction with di‐tert‐butylthioketene (1a). Analogously, alkylidenethiiranes 3a, b, d, g, h could be photoisomerized to isomers 4a, b, d, g, h. The corresponding rearrangement of S‐oxides 8 afforded isomers 9.
AnomericO‐Alkylation, 15. New 2/1‐Type Surfactants by AnomericO‐Alkylation of Mannofuranose
Authors: Terjung Andreas , Jung Karl‐Heinz , Schmidt Richard R.
Published: June 2010

New 2/1‐type surfactants were synthesized from glycerol derivatives2a–ehaving a long‐chain 2‐O‐alkyl substituent. Transformation of2a–dinto 1,3‐di‐O‐trifluoromethanesulfonates4a–dand their use in anomericO‐alkylation of mannofuranose7afforded after protective group removal β‐linked bis‐mannofuranosides13a–d. Preparation of mono‐O‐benzyl‐protected compounds5b–efrom2b–e, trifluoromethyanesulfonate formation, and then anomericO‐alkylation of7gave afterO‐debenzylation 1‐O‐mannofuranosides10b–e. Their unprotected 3‐hydroxy group was employed for the attachment of a β‐glucopyranosyl residue (→15b–e) and a sulfate group (→18b–e). Transformation of10b–einto alkylating agents19b–eand20b–e, respectively, enabled the attachment of the malonate group (→17b–e), oligoethylene glycol residues (→28b–e, 29b–e, 30b–e), iminodiacetic acid (→32b–e), and of the aspartate residue (→34b–e) as second hydrophilic group. Surface tension (σs) and critical micelle concentration (cmc) measurements with these compounds are reported and the results discussed.
Targeting RNA with Conformationally Restricted Oligonucleotides
Authors: Herdewijn Piet
Published: June 2010

A configurational and conformational complementarity between targeted ssRNA and the antisense oligonucleotide is a prerequisite for efficient hybridization. In the design of oligonucleotides that may hybridize strongly with natural RNA, one may select molecules with a preorganized structure. The hybridization process should then benefit from less negative entropy changes during duplex formation. Although, it is by now not completely clear which conformational restricted motif is best suited for this purpose, the N3′–P5′ phosphoramidate linkage and the hexitol nucleic acids seems to gain the objective.
Azo Bridges from Azines, XXI. Carbonyl and Enol Functionalities in Parallel Positions to Azo Groups
Authors: Brand Owe , Hünig Siegfried
Published: June 2010

The synthesis of compounds of type A3, carrying both, a silylenol and an azo group in parallel rigid positions, and the syntheses of ketone and diketone of type B and C, respectively, are reported. The crucial precursors, the mono‐ and dihydroxy acetals 2 and 3, both obtained from 1, are transformed by the already reported route to azo compounds 4 and 5. The latter compound is also prepared by dihydroxylation of the olefinic bridge in 7. Swern oxidation of alcohols 4, 6, and 5 yields ketones 12, 13, and 14. Enol silyl ether 15 (type A3) is obtained from 12 via its enolate 17 together with small amounts of diazetidine 16 which may arise from the equilibrium 17 18 19. By contrast, cyano ketone 20 yields the enol silyl ether 21 quantitatively.
Azo Bridges from Azines, XXII. [2 + 2] Photocycloaddition and 1,5‐Laticyclic Conjugation Between Parallel Azo Groups and π‐Systems The Symmetry Criterion in Azo‐Carbonyl Interactions
Authors: Brand Uwe , Hünig Siegfried , Martin Hans‐Dieter , Mayer Bernhard
Published: June 2010

The known 1,5‐lacticyclic interaction between parallel CC/ NN bridges in 1 in expressed by a bathochromic shift of the azo n‐π* transition of +7–10 nm. A CCCN bridge (2, 6) increases the bathochromic shift slightly, whereas a CC–OSiR3 bridge (3) cases a hypsochromic shift of −6 nm. In a R3SiO–C = C–CN bridge (4) the effect of the two substituents cancel each other. All these compounds (1–6, 13) undergo quantitative [2 + 2] photocycloaddition by n‐π* excitation. A novel transannular interaction between azo and carbonyl (20, 21: +8 nm) and 1,2‐dicarbonyl groups (24: ca. +20 nm) is observed. From photoelectron spectra and MO calculations neighboring group effects on the orbital energies in 20, 21, and 24 are assessed and discussed.
Glycosyl Imidates, 75. Synthesis of the Hexasaccharide Moiety of Globo H (Human Breast Cancer) Antigen
Authors: Lassaletta José M. , Schmidt Richard R.
Published: June 2010

The hexasaccharide moiety1cof the globo H antigen1awas synthesized based on a highly efficient strategy. To this end galactosyl trichloroacetimidate2was employed for the glycosylation of azidogalactose derivative3as acceptor to afford β(1→3)‐linked disaccharide7in high yield. Deacetylation and regioselective benzoylation and then fucosylation with trichloroacetimidate5gave trisaccharide10which was readily transformed into trichloroacetimidate12as glycosyl donor. Thus, with galactose derivatives4a, bas acceptors tetrasaccharides13a, bwere obtained in overall seven steps in high yields. Transformation of13into a glycosyl donor was best performed with13bvia 2‐O‐benzylation, 1‐O‐deallylation and then transformation into trichloroacetimidates20α,β. With6as acceptor the desired hexasaccharide21was obtained which could be fully structurally assigned. Hydrogenolytic debenzylation, debenzylidenation, and azido group reduction in one step and then acetylation concluded the synthesis of hexasaccharide1c.
Electrochemically Initiated Hydrocyanomethylation of N‐Heteroaryl‐Substituted Azomethines
Authors: Windeck Anne‐Kathrin , Hess Ulrich , Steckhan Eberhard , Reck Günter
Published: June 2010

The acetonitrile anion (1‐), generated by electrochemical initiation and chemical regeneration, may be used as cyanomethylation reagent for C,N double bond structures, e.g. for hydrocyanomethylation of π‐deficient N‐heteroaryl‐substituted Schiff bases (2–12) yielding the β‐aminonitriles (2a–12a). The synthesis is initiated by deprotonation of acetonitrile (1) to 1− by cathodically generated azomethine radical anions (2−·–12−·) followed by nucleophilic reaction of 1− with 2–12 up to its complete consumption, in a cyclic self‐reproducing process of 1−. Besides 2a–12a, 3,4‐heteroaryl‐substituted 4‐amino‐3‐butenonitriles and 1,3‐heteroaryl‐substituted 1,3‐diaminoisobutyronitiles are formed in the course of a nearly currentless reaction.
Anti‐histone H1 IgGs from blood serum of systemic lupus erythematosus patients are capable of hydrolyzing histone H1 and myelin basic protein
Authors: Magorivska Irina B. , Bilyy Rostyslav O. , Havrylyuk Anna M. , Chop'yak Valentyna V. , Stoika Rostyslav S. , Kit Yury Y.
Published: June 2010

Novel hydrolytic activity of the anti‐histone H1 antibodies (Ab) toward histone H1 and myelin basic protein (MBP) was shown. Blood serum of ten patients with clinically diagnosed systemic lupus erythematosus (SLE), and nine healthy donors (control) were screened for the anti‐histone H1 antibody‐ and anti‐MBP antibody‐mediated specific proteolytic activity. IgGs were isolated by chromatography on Protein G‐Sepharose, and four of ten SLE patients appeared to possess IgGs that were capable of cleaving both histone H1 and MBP. Such activity was confirmed to be an intrinsic property of the IgG molecule, since it was preserved at gel filtration at alkaline and acidic pH. At the same time, proteolytic activity was absent in the sera‐derived Ab of all healthy donors under control. Anti‐histone IgGs were purified by the affinity chromatography on histone H1‐Sepharose. Their cross‐reactivity toward cationic proteins (histones, lysozyme, and MBP) and their capability of hydrolyzing histone H1 and MBP were detected. However, these IgGs were not cleaving core histones, lysozyme, or albumin. Capability of cleaving histone H1 and MBP was preserved after additional purification of anti‐histone H1 IgGs by the HPLC gel filtration. The protease activity of anti‐histone H1 IgG Ab was inhibited by serine protease inhibitors. Copyright © 2010 John Wiley & Sons, Ltd.
Growth and cell division of Escherichia coli 173‐25 in the presence of some analogues of diaminopimelic acid
Authors: Chaloupka J. , Strnadová M. , Čáslavská J. , Vereš K.
Published: June 2010

The dap‐dependent mutant of Escherichia coli could grow in the presence of several analogues of diaminopimelic acid (dap). The multiplication proceeded without any apparent difference for several hours when dap was replaced with 2,6‐diamino‐4‐fluoro‐pimelic acid or lanthionine. Only growth without accompanying division could be detected in the presence of 2,6‐diamino‐4‐hydroxypimelic acid (hydroxy‐dap). 3H‐hydroxy‐dap was incorporated into the TCA precipitable material under these conditions. 2,4,6‐triaminopimelic acid, probably also 2,6‐diamino‐5‐oxo‐pimelic acid could not substitute dap in the synthesis of murein. The synthesis of DNA measured by the incorporation of 3H‐thymidine was not inhibited by hydroxy‐dap but the formation of the cross wall was impaired. The rods were longer, formed bulges in the central part of the cell and ultimately lyzed. Selenium‐lanththionine was more toxic but even in its presence some growth occurred and DNA synthesis took place. The replacement of dap with hydroxy‐dap stimulated the degradation of the wall mucopeptide during the growth.
Heterotrophic growth of the nitrogen fixing blue‐green alga Nostoc muscorum
Authors: El‐Refai A. H. , Nashat M. A. , Salem H. M.
Published: June 2010

Nostoc muscorum could grow heterotrophically and successfully utilized a number of different sugars. Glucose proved to be the best sugar tested for growth and nitrogen fixation. However, citrate was outstanding among the different organic acids tried in allowing a substantial algal growth and consequently a high amounts of fixed nitrogen. The chemical analysis of the algal cells as well as the culture filtrate revealed the presence of various amino acids as well as auxine like substances.
Septation sporogener und asporogener Bacillus megaterium‐Zellen während des Übergangs zu Stickstoff‐ und Kohlenstoff‐hunger
Authors: Kretschmer S. , Fiedler G.
Published: June 2010

First, the kinetics and frequency of sporulation of two Bacillus megaterium strains were determined after transition to nitrogen starvation. As the formation of the spore septum started at 1 hour after the shift, the initiation of sporogenesis was similar to that observed earlier in carbohydrate limited cultures. But later processes of sporulation were retarded and partly inhibited.

From these strains two sporulation defective mutants were isolated. In ammonia‐, resp. glucose‐ or arabinose‐limited cultures cell division of the sporogenic and asporogenic strains was studied electronmicroscopically. Samples were taken from 2 generations before the transition to the stationary growth phase (t0) through 3 hours after the shift.

Three types of division behaviour were observed during the transition to nitrogen‐(N) or carbon‐(C)‐starvation:

The initiation of division was inhibited already 1 ‐ 2 generations before cessation of net growth. In average, about 70% of all visibly initiated division septa were completed by t0 or shortly after that time. This type was expressed in all sp+‐cultures and in the N‐limited sp−‐populations.

Initiation of septum formation was stimulated 1 ‐ 2 generations before t0 in sp−‐strains under C‐limitation. About 80% of all initiated septa were completed, if citrate was absent.

The completion of the division septum was completely blocked independent of whether initiation was stimulated or inhibited. This inhibition of late division processes occurred with sp−‐strains under C‐ or N‐limitation in glucose‐citrate medium.

From these results it is concluded that the metabolism of sp+‐ and sp−‐strains differs already 1 ‐ 2 generations before t0. Concerning factors controlling division early sporulating cells resemble N‐starved cells, independent of the composition of the medium. Initiation of division is at least influenced by the ratio of catabolic to anabolic reactions in a cell. Initiation and completion of the septum are separately controlled steps of the division process, but probably not of the spore septum formation.
Detoxication of carboxin
Authors: Lyr H. , Ritter G. , Banasiak L.
Published: June 2010

Carboxin (= vitavax = DCMO) is rapidly oxidized by hydrogen peroxide or H2O2 generating systems as riboflavin, flavin enzymes with or without substrate, to the more water soluble nontoxic sulfoxid (DCMOS). Illumination enhances the inactivation. Peroxidase is without effect. Isolated mitochondria from sensitive as well as from insensitive fungal species have the ability to oxidize DCMO, which leads to a leakage of the compounds mainly in form of DCMOS from the mitochondria. Among several fungal species investigated only Ustilago maydis in vivo oxidizes DCMO to a higher degree. The further oxidation of DCMOS to the corresponding dioxid (DCMOD = plantvax) occurs only under certain conditions to a limited extent. Proteases are unable to attack the ‐ CONH‐bounding. It is assumed that in vivo mainly flavin enzymes are responsible for the rapid oxidative inactivation of DCMO (vitavax).
Stimulation des Wachstums von Torulopsis utilis (Candida utilis) in Saccharose‐haltiger Nährlösung durch verschiedene Vitamin‐ und Wuchsstoffquellen
Authors: Leopold H. , Španêlová M.
Published: June 2010

If Torulopsis utilis is grown in mineral solutions containing 2.5 and 5% sugar the yields of yeast dry matter are only 80% and 26%, respectively, relative to the theoretical value if an economical coefficient of 50% is used. In the presence of 30% of waste liquor of the citric acid fermentation (CAF‐waste liquor) the yields attain 70‐85%. The effects of corn‐steep, group B vitamins or of biotin are much lower. Theoretical and higher yields of biomass are obtained by the combination of the CAF‐waste liquor with corn‐steep. The stimulation of yeast growth by wet or dry mycelium of the mould Aspergillus niger was similar to that of the CAF‐waste liquor, both when acting alone and in combination with other carriers of vitamins or growth factors. A good effect was observed with a mixture of the CAF‐waste liquor and the mould mycelium, both products of the citric acid fermentation. Mineral salt solutions containing 7% sugar may be fermented with theoretical yields by adding larger quantities of CAF‐waste liquor and mould mycelium. An attempt is made to interpret some of the findings according to the hypothesis of overflow metabolism.
Untersuchungen über Phagenlysozym. II. Isolierung und Charakterisierung von kälteempfindlichen Mutanten im Lysozymgen des Phagen T4
Authors: Liebscher D.‐H. , Dauberschmidt R. , Rosenthal H. A.
Published: June 2010

With the help of bromouracil mutagenesis and selection of haloless plaques after chloroform treatment 15 haloless mutants of phage T4 were isolated.

The mutant cse BU56 proved to be cold‐sensitive due to a base substitution in the lysozyme gene according to the following criteria:

At 20 °C no plaques were formed; they appeared, however, after a temperature shift‐up.

The energy of activation of the lysozyme reaction was significantly increased as compared to that of the wild type.

This proves that an increased energy of activation of an essential enzyme‐catalyzed reaction is one of the causes for cold sensitivity in microorganisms.
Abbau von Tryptophan durch Candida guilliermondii, Stamm H17
Authors: Teuscher Gisela , Karczewski P. , Weide H.
Published: June 2010

In replacementexperiments L‐tryptophan was rapidly metabolized by Candida guilliermondii, strain H17, cultivated before in a medium containing n‐alkanes as sole carbon sources. After growth in a medium containing glucose tryptophan utilization was suppressed. Thin layer chromatography showed tryptophol as main metabolite. Kynurenine, anthranilic acid, and other substances of the aromatic pathway of tryptophan metabolism could not be detected. Feeding experiments showed a significant degradation of anthranilic acid, tryptamine, indolylpyruvic acid, and indolylacetic acid. As a metabolite of tryptamine utilization tryptophol has been identified. Degradation of formyl kynurenine and formyl anthranilic acid was within limits of error. Transamination and decarboxylation are discussed to be the primary reactions in the degradation of L‐tryptophan under the conditions used in this study.
Steroidtransformation with immobilized microorganisms VI. The reverse reaction of steroid‐1‐dehydrogenases from different micoorganisms in immobilized state
Authors: Atrat P. , Groh H.
Published: June 2010

Whole cells of Nocardia erythropolis, N. opaca and Mycobacterium phlei containing 4‐en‐3‐oxosteroid: (acceptor)‐l‐en‐oxidoreductase activities were immobilized by adsorption on DEAE cellulose and silica and by entrapment in polyacrylamide gel. The obtained biocatalysts were used in an anaerobic continuous column process to transform l,4‐dien‐3‐oxo‐steroids into 4‐en‐3‐oxo‐steroids. The half life of steroid‐1(2)‐reductase activity of the N. erythropolis was found to be up to 15 days. The DEAE‐cellulose‐adsorbed cells showed a slighthly higher relative activity than free cells. The influence of substrate concentration and the action of dimethylformamide were also investigated.
Purification and characterization of an extracellular β‐glucanase from Bacillus IMET B 376
Authors: Borriss R.
Published: June 2010

β‐1.3‐1.4‐glucanase (E.C.3.2.1.73) was obtained in highly purified form from the culture fluid of Bacillus IMET B 376 by precipitation with ammonium sulfate, adsorption on CM‐cellulose and then affinity chromatography on lichenan‐Sepharose 4B. The purified enzyme was active on lichenan and barley glucan but not on laminarin and on CM‐cellulose. The molecular weight of the enzyme was estimated to be 26,000 daltons. The Km values for lichenan and barley glucan were determined to be 1.43 and 1.15 mg/ml, respectively. The β‐glucanase has a broad pH optimum between 6 to 8, and was particularly thermostable in presence of Ca++.
Vergleichende physiologische Untersuchungen zwischen Candida spec. H und der Mutante H 13 unter Stickstoffmangelbedingungen
Authors: Brückner B. , Tröger R.
Published: June 2010

With Candida spec. H and the mutant H13 during nitrogen starvation we studied the changes occurring in the macromolecular cell composition. In the absence of nitrogen, but in the presence of n‐alkanes as carbon source, both the nucleic acid and protein levels of the dried yeasts rapidly decreased. At the same time carbohydrates and lipids were accumulated. Candida spec. H predominately increased carbohydrate content, whereas the mutant accumulated significantly higher amounts of lipids. The main components of the cellular carbohydrates and the fatty acid content were analyzed, and the results were discussed.
Synthese Poly(A)‐haltiger RNA in auswachsenden Sporen von Bacillus subtilis
Authors: Hecker M. , Prösch S. , Mach H. , Mach F.
Published: June 2010

The synthesis of poly (A) ‐containing RNA in outgrowing spores of Bacillus subtilis was studied. A significant amount of RNA puls‐labelled with 3H‐uridine is polyadenylated. With the beginning of RNA synthesis in outgrowing spores labelled poly(A)‐containing RNA was detected. The amount of poly(A)‐RNA during the outgrowth and first cell division remains constant. Besides poly(A)‐RNA the synthesis of tRNA and rRNA occurs. These results indicate a simultaneous activation of synthesis of tRNA, rRNA as well as of poly(A)‐contaning RNA during outgrowth of B. subtilis spores.
An experimental approach to energy balance in a microbial process using the dichromate oxidation method
Authors: Nikolajewski H. E. , Meineke L. , Wettig Gudrun
Published: June 2010

The dichromate oxidation method was used to determine the number of reduction equivalents of organic substrates, cell mass and extracellular products in aerobical batch cultivations of Bordetella pertussis.

The reduction equivalents obtained by this method were transformed into caloric values based on the fact that heat of reaction per equivalent oxygen consumed by oxidation of different organic substances is relatively constant. According to the law of conservation of energy a complete energy balance associated with an aerobical microbial process was developed using the caloric values mentioned above.
Effects of chloramphenicol on the thermal profile of Saccharomyces cerevisiae
Authors: Madeira‐Lopes A. , van Uden N.
Published: June 2010

Chloramphenicol decreased the maximum temperature for growth of a petite mutant of Saccharomyces cerevisiae, shifted the Arrhenius plot of thermal death to lower temperatures and shortened correspondingly, the Arrhenius plot of growth, while an associative thermal profile was maintained. At saturating concentrations (about 5 mg per ml) of chloramphenicol in liquid mineral medium with vitamins and glucose the final maximum temperature for growth was depressed from about 40°C to about 37°C. The results suggested that chloramphenicol acted in the mutant on targets other than mitochondrial ribosomes and that these targets are identical or associated with the death and Tmax sites of the yeast.
A direct selection method for isolating antimutators of Escherichia coli
Authors: Quinones A. , Piechocki R.
Published: June 2010

A screening procedure based on the formation of lactose‐fermenting papillae on lactose‐nonfermenting bacterial colonies has been described. Due to supplementation of 50 μg/ml 2‐aminopurine in EMB plates the frequency of papillae rose to an average number of 28 papillae per colony. Of 150,000 mutagenized colonies inspected 16 colonies were detected with drastically reduced or no papillae per colony.
Gewinnung und Charakterisierung kohlenhydratspezifischer Antikörper aus anti‐Candida utilis Serum
Authors: Rademacher K.‐H.
Published: June 2010

Mannan of Candida utilis was hydrolyzed in oligosaccharides of different chain lenghts. Mannohexaose and mannopentaose were shown to be the immunodominant group of this mannan. The oligosaccharides obtained were bound to sepharose by way of β‐(p‐aminophenyl) ethylamine. Immunoglobulins against mannohexaose down to mannodiose were obtained using affinity chromatography of the anti‐C. utilis serum. The affinity columns were filled with sepharose‐oligosaccharide gels. The serological activity was proved by agglutination and precipitation.
Effect of microtubule inhibitors on the tubulin system of Dictyostelium discoideum
Authors: Rubino S. , Unger E. , Fogu G. , Cappuccinelli P.
Published: June 2010

Indirect immunofluorescence with antibodies to microtubular proteins has been used to investigate the microtubule system of Dictyostelium discoideum vegetative amoebae and the action of several compounds that interfere with that system. All the inhibitors tested show an antimicrotubular effect.

Colchicine, vinblastine, nocodazole, thiabendazole, and isopropyl‐N‐phenyl‐carbamate (IPC) seem to act mainly by destroying microtubules leaving the appearance of nuclei associated organelles (NAOs) undisturbed. On the other hand griseofulvin also affects NAOs which disappear in treated cells.
Wirkung von Pentachlornitrobenzol (PCNB) auf die Ultrastruktur von Mucor mucedo und Phytophthora cactorum
Authors: Casperson G. , Lyr H.
Published: June 2010

The effect of PCNB in various concentrations on the ultrastructure of Mucor mucedo and Phytophthora cactorum was analyzed after an incubation period of 2 hours. The most striking effect in both fungi was a diffuse lysis of the internal structure of the mitochondria which differs markedly from the lysis induced by etridiazol (terrazol). Moreover an enlargement of the perinuclear space and an increased formation of vacuoles was observed.

In Mucor mucedo, but not in Phytophthora cactorum a pathological thickening of the cell wall was observed. Although after 2 hours incubation with PCNB Phytophthora gave similar ultrastructural reactions in the mitochondria as Mucor, in growth experiments on agar dishes this species was 5–10 times less sensitive to PCNB compared to Mucor.
Anomalous cell wall synthesis in Mucor mucedo (L.) FRES. induced by some fungicides and other compounds related to the problem of dimorphism
Authors: Lyr H. , Casperson G.
Published: June 2010

An anomalous cell wall thickening in Mucor mucedo is induced already within 60–120 min by some fungicides (etridiazol, chloroneb, pentachloronitrobenzene, dicloran, drazoxolon, biphenyl) as well as with a N2‐atmosphere or high concentrations of glucose, but not with 2,4‐dinitrophenol, chlorinated phenols, dichlofluanid and antimycin A. This effect seems to be identical to the change from the mycelial (M‐) to the yeast (Y‐) form in dimorphic fungi, which can be achieved by culture conditions as well as by addition of chemicals. The cause seems to be a specific, complex change in the metabolic state. A scheme of regulation is presented which explains most of the experimental results described till now.
Phosphate release in turimycin fermentations
Authors: Müller P. J. , Hilliger H. , Menner M. , Forberg W.
Published: June 2010

The important effect of release of soluble phosphate from complex media constituents during the turimycin fermentation is demonstrated by investigation of process kinetic and phosphate balance. The observed changes in physiological parameters and the diauxic growth are discussed in connection with extracellular enzymes formation hydrolyzing phosphate‐containing complex media constituents.
Effects of different factors on the sporulation of Pithophora oedogonia (MONT.) WITTROCK
Authors: Agrawal S. C. , Sarma Y. S. R. K.
Published: June 2010

The present study emphasizes the effects of different qualities of visible light, intensities of white light, temperature and pH on the sporulation in the green alga Pithophora oedogonia (MONT.) WITTROCK. Of the different qualities of light used, green light was found to delay the initiation of sporulation. Percentage of sporulation was greatly decreased in yellow light followed by red light. Delay in time taken for initiation of sporulation and decrease in percentage sporulation were observed at 0.25 and 0.5 K lux intensity of white light. Sporulation upto the extent of its natural population was achieved with white light between 2 to 3.5 K lux, temperature between 20 to 30 °C and pH between 4–9.
Streptomyces maghwi, a new species producing roflamycoin
Authors: Afzal M. , Nimer N. D. , Nazar M.
Published: June 2010

A new Streptomyces species is described for which the name S. maghwi is proposed. The organism is characterized by a pink mass of aerial mycelium, spiral spore chains, spores with smooth surfaces and a nonchromogenic vegetative mycelium. S. maghwi produces roflamycoin (SCHLEGEL et al. 1981) formerly known as flavomycoin (SCHLEGEL et al. 1971). The type strain of S. maghwi is deposited with CBS, Netherland.
Allgemeine Kontrolle der Aminosäurebiosynthese in Mutanten von Candida spec. EH 15/D
Authors: Bode R. , Casper P.
Published: June 2010

The general control of amino acid biosynthesis was investigated in Candida spec. EH 15/D, using single and double mutant auxotrophic strains and prototrophic revertants starved for their required amino acids. These experiments show that starvation for lysine, histidine, arginine, leucine, threonine, proline, serine, methionine, homoserine, asparagine, glutamic acid or aspartic acid can result in derepression of enzymes. A correlation was found between the degree of derepression, growth of strains, and concentration of required amino acids. The amino acids pcol pattern of mutants and revertants is different from that in the wild type strain.
A comparison of manganese oxidation by growing and resting cells of a freshwater bacterial isolate, strain FMn 1
Authors: Zapkin M. A. , Ehrlich H. L.
Published: June 2010

A bacterial isolate, strain FMn 1, from reservoir sediment oxidized Mn2+ when tested in growing culture and resting‐cell suspension. The oxidation was biologically mediated and not the result of autoxidation because at a MnSO4 · H2O concentration of 0.05%. The pH remained below 7.5 for the duration of the experiments. The productions of manganese oxide was qualitatively and quantitatively demonstrated. Teh manganese‐oxidizing activity of this organism was found to be inducible.
A novel Mn2+‐oxidizing enzyme system in a freshwater bacterium
Authors: Zindulis J. , Ehrlich H. L.
Published: June 2010

Manganese oxidation by cell suspensions and cell extracts of a freshwater bacterium, designated strain FMn 1, was investigated. Manganese appeared to be oxidized in the periplasmic space. A conventional, membrane‐bound electron transport system was not utilized. An enzyme or enzyme complex and a cofactor, each of different molecular size, were located in different parts of the cell envelope. Results suggest that the cofactor reacts with manganese in the periplasmic space and that in the presence of oxygen it is reoxidized by the reoxidized by the enzyme. The enzyme is probably loosely bound to the membrane. A combination of enzyme and cofactor in a crude preparation exhibited a pH optimum at around 7.0. The enzyme exhibited a temperature optimum at around 30 °C. No temperature optimum was found for the cofactor. The enzyme was heat‐labile and inhibited by mercuric chloride and para‐chloromercuribenzoate. The cofactor was heat‐stable and could oxidize manganese under anaerobic conditions. The enzyme system appears to be different from others so far described.
Molekularbiologie der Keimung von Bacillus‐Sporen
Authors: Hecker M.
Published: June 2010

The review deals with recent results and problems of gene expression during germination of Bacillus spores. Three problems were selected:

The activation of metabolism as a prequisite for the synthesis of nucleic acids and proteins.

The activation of nucleic acid and protein synthesis during germination.

The gene expression programme of germinating spores.

Using the highly sensitive two‐dimensional polyacrylamide gel analysis three major classes of proteins were distinguished, depending on the time of onset and duration of their syntheses:

proteins made throughout germination (main class)

proteins whose synthesis started only after a lag phase and then continued thoughout germination, and

proteins which are synthesized only during the early phases of germination.

The programme of protein synthesis is an indicatoir for the control of gene expression during germination. The regulation of expression of these major gene groups during spore outgrowth is discussed.
Micro‐Raman analysis of GaAs Schottky barrier solar cell
Authors: Jothilakshmi R. , Ramakrishnan V. , Kumar J. , Sarua Andrei , Kuball Martin
Published: June 2010

Gallium arsenide (GaAs) cells have been in the race with silicon single‐crystal cells for the highest efficiency photovoltaic devices. The annealed, irradiated Schottky barrier (SB) solar cells were characterised using micro‐Raman spectroscopy at three different regions: namely, at the (1) ohmic contact region, (2) unirradiated region and (3) irradiated region. We also present a micro‐Raman study of the damage process in annealed GaAs SB solar cells bombarded by high‐energy ions. A Gaussian line shape was fitted to the Raman spectra of the longitudinal optical phonon A1(LO), and parameters such as intensity, full width at half maximum (FWHM) and the area under the peak were obtained for the different annealing temperatures. Biaxial stress (σ), carrier concentration (n), depletion length (Ld), dislocation velocity (ν) and life time of the first‐order optical phonon (τ) of the A1(LO) mode of the irradiated region of the samples annealed at different temperatures were calculated. Copyright © 2010 John Wiley & Sons, Ltd.
Preparation of silver nanoparticles on zinc oxide nanowires by photocatalytic reduction for use in surface‐enhanced Raman scattering measurements
Authors: Chen I‐Cherng , Liou Yen‐Chen Maggie , Yang Jyisy , Shieh Tien‐Yu
Published: June 2010

To increase the sensitivity in surface‐enhanced Raman scattering (SERS) measurements, the high surface area of zinc oxide nanowires (ZnO NWs) was used. ZnO NWs on silicon substrates were prepared and used as substrates for further growth of silver nanoparticles (AgNPs). Ultraviolet (UV) irradiation was used to reduce silver ions to AgNPs on the ZnO wires. With proper growth conditions for both ZnO NWs and AgNPs, the substrates exhibit SERS enhancement factors greater than 106. To understand the influences of the morphologies of the ZnO NWs on the growth of AgNPs, the growing time and temperature were varied. The concentration of silver nitrate and irradiation time of UV radiation were also varied. The resulting AgNPs were probed with para‐nitrothiophenol to quantify the SERS enhancements obtained from the varying conditions. The results indicate that ZnO NWs could be grown at temperatures higher than 490 °C and higher growth temperatures result in smaller diameter of the formed ZnO NWs. Also, the morphologies of ZnO NWs did not significantly alter the SERS signals. The concentration of silver nitrate affects the SERS signals significantly and the optimal concentration was found to be in the range of 10–20 mM. With irradiation times longer than 90 s, the resulting AgNPs showed similar SERS intensities. With optimized conditions, the AgNPs/ZnO substrates are highly suitable for SERS measurements with a typical enhancement factor of higher than 106. Copyright © 2010 John Wiley & Sons, Ltd.
Inhibition of acid‐induced decomposition of diphenyltriazenes by complexation with cyclodextrins
Authors: Xu Tingting , Asadi Atefeh Vaez‐Zadeh , Barra Mónica
Published: June 2010

Acid‐promoted NN bond cleavage in 1,3‐diphenyltriazenes (X‐Ph‐N=N‐NH‐Ph‐X; X = H, 4‐OCH3), leading to formation of diazonium ions and anilines, is strongly inhibited in aqueous solutions in the presence of cyclodextrins (CDs). The inhibition is ascribed to the formation of inclusion complexes that render the guest diphenyltriazene significantly less basic as a result of the less polar nature of the CD cavity (a microsolvent effect). Association equilibrium constants for 1:1 host–guest complexes increase in the order α‐CD <β‐CD ∼ permethyl‐β‐CD < hydroxypropyl‐β‐CD, with values for X = 4‐OCH3 being larger than those for X = H. In the case of α‐CD, formation of 2:1 host–guest complexes is also involved. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 567–574, 2010
Production and nutritional aspects of human milk fat substitutes
Authors: Mu Huiling
Published: June 2010

Human milk fat substitute (HMFS), one of the vital ingredients of infant formula, constitutes about 50% of energy intake for many infants. The composition of HMFS depends on the raw material and the production technology. Both human and animal studies have shown that absorption of fats and minerals are affected by triacylglycerol structures and fatty acid compositions of HMFS. Additionally, the level of other micronutrients, such as fat‐soluble vitamins, can also be affected by production processes. The ultimate goal in the design of infant formula is to mimic human milk, regarding both lipids and other micronutrients. This paper covers human milk fat and selected HMFS as well as their impact on absorption of fat and calcium and illustrates recent progresses and findings.
Soybean Peroxidase Catalyzed Enzymatic Synthesis of Pyrrole/EDOT Copolymers
Authors: Tewari Arti , Kokil Akshay , Ravichandran Sethumadhavan , Nagarajan Subhalakshmi , Bouldin Ryan , Samuelson Lynne A. , Nagarajan Ramaswamy , Kumar Jayant
Published: June 2010

Pyrrole/EDOT copolymers were synthesized using environmentally benign enzyme catalysis. PSS was used as the solubilizing template and charge‐balancing dopant. Soybean peroxidase was utilized as a catalyst for the copolymerization reactions to yield poly(pyrrole‐EDOT)/PSS complex. Systematic studies were conducted with varying monomer feed ratios, temperature, and pH. Here we report for the first time, the enzyme catalyzed polymerization of pyrrole and EDOT at an elevated pH = 5. The polymer composition was determined using X‐ray photoelectron spectroscopy. Spectroscopic characterization [UV‐Vis, FTIR], thermal analysis, and electrical conductivity measurements for these complexes indicated the formation of stable conducting copolymers.

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Electrospinning of Cellulose‐Based Fibers From NaOH/Urea Aqueous System
Authors: Qi Haisong , Sui Xiaofeng , Yuan Jinying , Wei Yen , Zhang Lina
Published: June 2010

Cellulose‐based fibers were prepared by electrospinning from cellulose dissolved in NaOH/urea in the presence of a small amount of polyol binders. The as‐spun products were examined with SEM. Pure cellulose solution did not produce fibrous materials, because it often formed spherical nanoparticles with diameters ranging from 100 to 300 nm. However, bicomponent fibrous materials were obtained successfully from mixtures of cellulose and HMPEG or PVA by electrospinning. The cellulose/HMPEG electrospun fibers had average diameters of 400 nm. The content of NaOH and urea as well as the stiffness of cellulose chains were found to have significant effect on the electrospinning process.

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[Russian Text Ignored]
Authors: [Russian Text Ignored]
Published: June 2010

[Russian Text Ignored].
Rothe's Method for Semilinear Parabolic Problems with Degeneration
Authors: Pluschke Volker
Published: June 2010

The paper deals with semilinear parabolic initial‐boundary value problems whereat the coefficient g(x, t) of the time derivative may vanish at a set of zero measure. Existence of a local weak solution of the problem is proved by means of semidiscretization in time. In order to omit a growth limitation for the nonlinearity we derive uniform boundedness of the approximates in L∞ (QT). Moreover, the weak solution turns out to be continuous even in the points of degeneration.
Left K‐Completeness in Quasi‐Metric Spaces
Authors: Romaguera Salvador
Published: June 2010

Regular left K‐sequentially complete quasi‐metric spaces are characterized. We deduce that these spaces are complete Aronszajn and that every metrizable space admitting a left K‐sequentially complete quasi‐metric is completely metrizable. We also characterize quasi‐metric spaces having a quasi‐metric left K‐sequential completion in terms of certain bases of countable order.
Schauder Estimates for the Single Layer Potential in Hydrodynamics
Authors: Deuring Paul , Varnhorn Werner
Published: June 2010

Let Ω be an open set in ℝN(N ⩾ 3), with compact boundary ϑΩ of type C1,α(ϵ(0,1)). We show that the single layer potential Ef, related to the stationary Stokes system on Ω, belongs to C1,α(ϑΩ)N, provided the source density f belongs to Cα(ϑΩ)N. In addition, we prove a related estimate of the function E(f)ϑΩ and its tangential derivatives.
Meromorphic Factorization, Partial Index Estimates and Elastodynamic Diffraction Problems1)
Authors: Câmara M. C. , Lebre A. B. , Speck F.‐O.
Published: June 2010

This work is motivated by some elliptic boundary and transmission problems in mathematical physics, in particular by elastodynamic wave propagation. The analytical solution of the boundary pseudodifferential equations requires a generalized factorization of the lifted Fourier symbol which is a non‐rational matrix‐function. In the factorization procedure poles and increasing terms appear, and cause enormous practical and theoretical problems due to the possible occurance of partial indices different from zero. The paper presents an approach which avoids those difficulties by use of a factorization of the symbol matrix into meromorphic factors. An operator theoretic interpretation yields resolvents up to finite dimensional operators, whose ranks are closely related to partial indices, order of the algebraic increase at infinity, and the multiplicities of the poles in the factors.
Classification of Twistor Spaces with a Pencil of Surfaces of Degree 1, Part I
Authors: Kurke Herbert
Published: June 2010

We display a family of compact complex 3‐manifolds which yields all twistor spaces containing a pencil of surfaces transversal to the twistor lines. This also yields explicit families of self‐dual metrics on connected sums of complex projective planes. This yields a completely alternative approach to a class of such metrics which was recently found by Claude le Brun [11].
On Cuspidal Cohomology of Arithmetic Groups and Cyclic Base Change
Authors: Rohlfs Jürgen , Speh Birgit
Published: June 2010

Let F be a totally real number field and let E|F be a cyclic Galois extension with Galois group generated by σ. Let G0|F be a connected semi simple algebraic group defined over F, put G = res ℚ(G0 x FE) and assume that G0(F ⊗ ℝ) contains a compact Cartan. Let Y be the locally symmetric space which is determined by G(ℝ) and by a sufficiently small σ‐stable arithmetic subgroup Γ of G(ℚ). Then we show that the cuspidal cohomology of Y is non trivial. Moreover we give an estimate of the growth of the cuspidal cohomology if Γ shrinks to {e} in a certain way.
The Stieltjes Moment Problem with Complex Exponents
Authors: Duran Antonio J.
Published: June 2010

In this paper, we characterize the complex sequences (zn)n which satisfy the following condition: For each complex sequence (an)n, there exists a function f such that the functions tznf(t) are Lebesgue integrable and an = ∫ tznf(t)(dt) for all n∫. In this case, we give for every sequence (an)n infinitely many C∫ functions f satisfying some growth conditions in x = 0 and x = + ∫, and such that an = ∫ tznf(t)dt.

Finally, we extend this result for Banach space valued functions.
Unconditional Orthonormal Systems
Authors: Defant Martin , Junge Marius
Published: June 2010

We show that a Banach space X is isomorphic to a Hilbert space if and only if the trigonometric system is unconditional in L2 (II, X). If the unconditionally constant is equal to one then X is even isometric to a Hilbert space.
λ‐Variation and Hausdorff Distance
Authors: Prus‐Wiśniowski Franciszek
Published: June 2010

It is shown that points of varying monotonicity of a function play an important role in calculation of its λ‐variation. It is proven that for a given continuous function x: [0,1] → IR of bounded λ‐variation, the function A → λ‐var(x, A) is continuous on the metric space (ℋ︁, dH) of all closed subsets of [0, 1] with Hausdorff distance. Another function from (ℋ︁, dH) into ℛ is used to characterize the compactness in CΛBVc, i.e. in the Banach space of continuous functions that are continuous in λ‐variation. As a corollary the separability of CΛABVc is proven.
Estimates on Complex Interactions in Phase Space
Authors: Martinez André
Published: June 2010

We propose a method to study the complex interactions (or microlocal tunneling) between electronic levels that do not intersect in the real domain. The method consists in using a special kind of Fourier‐Bros‐Iagolnitzer transformation, and in adjoining an exponential weight to the L2‐type Hilbert spaces which are associated to a complex Lagrangian manifold and have been introduced by Helffer and Sjöstrand for the study of resonances.
Characterization of Temperature Functions with Isolated Singularity
Authors: Chung Soon‐Yeong , Kim Dohan
Published: June 2010

Every temperature function with an isolated singularity can be represented as a sum of a temperature function without singularity and an infinite sum of derivatives of a Green function. This generalizes the result of WIDDER on the characterization of positive temperature functions.
Sharp Generalized Carleman Inequalities with Minimal Information about the Spectrum
Authors: Dechevski Ljubomir T. , Persson Lars Erik
Published: June 2010

Let H and T: H → H denote a separable Hilbert space and an operator in a Schatten‐von Neumann ideal Sp(H), respectively. Consider the resolvent operator (λI ‐ T)−1, where I is the identity operator and λ belongs to the resolvent set of T. Some sharp bounds for the uniform operator norm of (λI ‐ T)−1 are derived in some situations of particular interest for certain applications, namely when only partial or minimal information about the spectrum is available. The results obtained may also be regarded as generalizations of Carleman's inequality for quasinilpotent operators.
Entropy Numbers in Weighted Function Spaces and Eigenvalue Distributions of Some Degenerate Pseudodifferential Operators II
Authors: Haroske Dorothee , Triebel Hans
Published: June 2010

This paper is the continuation of [17]. We investigate mapping and spectral properties of pseudodifferential operators of type Ψ with χ χ ϵ ℝ and 0 ≤ γ ≤ 1 in the weighted function spaces B (ℝn, w(x)) and F (ℝn, w(x)) treated in [17]. Furthermore, we study the distribution of eigenvalues and the behaviour of corresponding root spaces for degenerate pseudodifferential operators preferably of type b2(x) b(x, D) b1(x), where b1(x) and b2(x) are appropriate functions and b(x, D) ϵ Ψ. Finally, on the basis of the Birman‐Schwinger principle, we deal with the “negative spectrum” (bound states) of related symmetric operators in L2.
On Multifunctionals in the Musielak‐Orlicz Spaces of Multifunctions
Authors: Kasperski Andrzej
Published: June 2010

We introduce the notions of Xd,s(x),φ‐linear multifunctional and Xd,s(x),φ‐linear continuous multifunctional. We generalize the theorems on linear bounded functionals in the Musielak‐Orlicz space.
Riesz Means on Compact Riemannian Symmetric Spaces
Authors: Li Luoqing
Published: June 2010

We study approximation properties of the Riesz means on compact symmetric spaces of rank one. To do so we establish equivalences between the Riesz means and Peetre K‐moduli and estimate the weak type and the uniform approximation of the Riesz means at the critical index. The relations between the Riesz means and the best approximation as well as the Cesàro means are also considered.
Filter Functions with Exponential Convergence Order
Authors: Denk Robert
Published: June 2010

Oversampled functions can be evaluated using generalized sinc‐series and filter functions connected with these series. A standard filter function is given by exp ((ζ2 − 1)−1). We show that the Fourier transform of this filter posseses the convergence order 0(exp (−√x)), improving an estimation given in [10]. Moreover, we define a family of filter functions with convergence order O(x · exp (−xσ)) with σ arbitrary close to 1.
Stochastic Integration for Some Rough Non‐adapted Processes
Authors: Imkeller Peter , Schmidt Wolfgang
Published: June 2010

For the Wiener process W on the unit interval and 0 ⩽ θ ⩽ 1/4 consider the non‐adapted process ut =sgn(Wt−θ)sgn(W1−WT+θ), θ⩽t⩽1−θ. By giving explicit descriptions of their expansions in terms of generalized Hermite polynomials we show that they possess Skorohod integral processes. In the more interesting case θ = 0, a component due to the interaction of forwards and backwards Wiener process seems to dominate the non‐interaction part, whereas for θ > 0 interaction drops geometrically with respect to non‐interaction. We translate these purely analytic properties into more familiar terms of samples of stochastic processes. Firstly, we construct simple approximations of the integral process which are of the type of Riemann sums. We then show that their quadratic variations are the same as for the Wiener process on [θ, 1 − θ]. Finally, using the fact that W remains a semimartingale if its filtration is enlarged by W1, we compare the resulting Ito integral process to the Skorohod integral process of u in case θ = 0. We show that they differ by a local time. Consequently the Skorohod integral process of u is a semimartingale.
Unitary Representations and Coadjoint Orbits for a Group of Germs of Real Analytic Diffeomorphisms
Authors: Leitenberger Frank
Published: June 2010

The method of coadjoint orbits is developed for the group of real analytic germs of diffeomorphisms φ with φ(0) = 0 and φ′(0) = 1. The form of all infinite dimensional coadjoint orbits is described. Classes U of unitary representations are constructed. In the case n = 2 these representations are related to coadjoint orbits.