bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixed Chloro(dialkylamido) Complexes of Zirconium and Hafnium
Authors: Brenner Simon , Kempe Rhett , Arndt Perdita 
Published: January 2005

AbstractChloro(dialkylamido) complexes of the type (R2N)2MCl2(THF)2 (R = Me, Et; M = Zr and R = Me; M = Hf) were synthesized in a conproportionation reaction by adding an equimolar amount of the corresponding M(NR2)4 to an ether slurry of MCl4 in the presence of THF. X‐ray crystal structure determinations of (Et2N)2ZrCl2(THF)2 (1 a) and (Me2N)2ZrCl2 · (THF)2 (1 b) reveal a distorted octahedral coordination geometry where the sterically demanding dialkylamide ligands force the chloride and the THF ligands out of their ideal position. Dynamic NMR investigations indicate an equilibrium of complexes with coordinated THF at low temperature in accordance with the structure determined by X‐ray crystallography and of chloro‐amido complexes that do not bind THF (at higher temperature).
Preparation, crystal structure, and infrared characterization of the first thiocyanato‐oxy‐antimonate(III) [(CH3)4N]2[Sb6O4(NCS)12]
Authors: Bertazzi N. , Alonzo G. , Saiano F. , Battaglia L. P. 
Published: January 2005

AbstractThe salt [(CH3)4N]2[Sb6O4(NCS)12] is the first identified thiocyanato‐oxy‐antimonate(III) complex. Reported are details of the synthesis, relevant infrared data and its x‐ray structure. The compound crystallizes in the triclinic space group P1 with Z = 2 (C10H12N7O2S6Sb3) and unit cell dimensions a = 11.314(6), b = 12.846(3), c = 8.679(2) Å; α = 91.93(3)°, β = 90.31(3)° and γ = 99.13(3)°. It contains centrosymmetric [Sb6O4(NCS)12]2− anions packed with isolated tetramethyl‐ammonium cations. The fundamental structural element of the anion is provided by the fusion of three SbOSbO rings forming a zig‐zag portion of a ribbon, only slightly pleated. Peculiar is the unequivalence of the six thiocyanate ligands, though all primarily N‐bonded to antimony atoms. Three thiocyanates are terminal while other three are asymmetrically N‐bridging between two centers; two of this latter type are also interconnecting the anions via Sb⋅⋅⋅S contacts. There are three different antimony environments, the primary bonding at Sb being to one nitrogen and three oxygens, to one oxygen and three nitrogens and to two atoms of each type.
Ternäre Thalliumplatin‐ und Thalliumpalladiumchalkogenide Tl2M4X6. Synthesen, Kristallstruktur und Bindungsverhältnisse
Authors: Bronger W. , Bonsmann B. 
Published: January 2005

AbstractDie Verbindungen Tl2Pt4S6, Tl2Pt4Se6, Tl2Pt4Te6 und Tl2Pd4Se6 sind durch Schmelzreaktionen aus den jeweiligen Elementen oder durch die Umsetzung von Thalliumcarbonat, Übergangsmetall‐ und Chalkogenpulver im Temperaturbereich zwischen 400°C und 950°C darstellbar. Röntgenographische Untersuchungen an Einkristallen und an pulverförmigen Proben ergaben, daß die Verbindungen in einem neuen Strukturtyp kristallisieren, der als Stapelvariante schon bekannter Atomanordnungen der Alkalimetallplatinchalkogenide A2Pt4X6 (A ≙ Alkalimetall, X ≙ S, Se) aufgefaßt werden kann. Die geringen Atomabstände Thallium‐Platin bzw. Thallium‐Palladium deuten in übereinstimmung mit den Ergebnissen von Extended‐Hückel‐Rechnungen auf eine kovalente Bindung zwischen dem Hauptgruppen‐ und dem übergangsmetall hin.
Zur Bildung von Vinylverbindungen des Lanthans und Lutetiums
Authors: Thiele Karl‐Heinz , Seifert Ronald 
Published: January 2005

AbstractPermethyllanthanocenchlorid reagiert mit Vinyllithium unter Vinylkopplung zu dem Butadienkomplex [Li(DME)3] [Cp2*La(C4H6)] (1). Ausgehend von der entsprechenden Lutetiumverbindung konnte dagegen das gesuchte Cp2*Lu(CHCH2) · LiCl · DME (4) als wenig beständige Substanz erhalten werden. Als stabilere Alkenylverbindungen werden das Cp2*LaCPhCMe2 · 2 THF (2) und Cp2*LuCPhCMe2 · MgCl2 · DME (3) beschrieben. Die Charakterisierung der Komplexe erfolgte durch ihre 1H‐ und 13C‐NMR‐Spektren.
Monomeres Trilithium‐tris[tert‐butyldimethylsilylamido]phenylsilan, PhSi[NLi(THF)SiMe2CMe3]3 ‐‐ Darstellung und Kristallstruktur
Authors: Hemme I. , Klingebiel U. , Freitag S. , Stalke D. 
Published: January 2005

AbstractLithiiertes tert‐Butyldimethylsilylamin reagiert mit Trifluorphenylsilan im molaren Verhältnis 2:1 bzw. 3:1 zu den Bis‐ und Tris(silylamino)silanen 1 [(Me3CSiMe2NH)2 · SiFPh] und 2 [(Me3CSiMe2NH)3SiPh]. In der Reaktion von 2 mit n‐BuLi in Hexan/THF entsteht das Trilithiumderivat 3 [Me3CSiMe2NLi(THF)]3SiPh. 3 kristallisiert als Monomer und bildet im Kristall drei planare, viergliedrige (LiNSiN)‐Ringe. Die Ergebnisse der Kristallstrukturanalyse von 3 werden mitgeteilt.
Ethical dilemmas in context: Some preliminary questions
Authors: Bond Meg A. 
Published: January 2005

SummaryI have tried to build on O'Neill's thought‐provoking paper by examining two influences that shape and define ethical dilemmas in the community: our personal agendas and the broader context. The first influence is the way in which our personal and professional values shape our agendas for community work. The way these agendas frame the choices for action are a force to be recognized separate from the question of who constitutes our community constituency. Our values may push us into proactive roles and we must face the way our actions make personal/political statements. The broader context of the community situation and the ways in which resource limitations frame the ethical question also need to be actively recognized. Otherwise there is a danger of making the psychologist the victim by posing the ethical dilemma as a question of how they alone should find a solution.The nature of our personal agenda must be clear before we ask “responsible to whom?” The broader context must be considered before we ask “responsible for what?”
Toward a synergism of rural development and community psychology
Authors: Omprakash S. 
Published: January 2005

ConclusionThe community psychologist should be attuned to the phenomenon that deprived communities are not always attracted by goals that are understandable to the middle‐class power structure. Persons in a constant battle against poverty settle at first for immediate visible gains. An increase in the number of children getting lunch at school is tangible; a revision of the curriculum to produce better competence in mathematics is not quite so tangible.
Context and process: An ecological view of the interdependence of practice and research: An invited address by James G. Kelly
Authors: Altman David G. 
Published: January 2005

SummaryJames G. Kelly has made important and wide‐ranging conributions to community psychology. The field is fortunate to have a member with his vision and commitment. In the paper presented here, Jim discusses the advantages that arise when scientists and citizens work as collaborative partners in community research. As with his previous work, his ideas provide new insights into the role of community psychology in and for the community.
Refining fit: Conceptual and methodological challenges
Authors: Pargament Kenneth I. 
Published: January 2005

ConclusionsIn some respects the development of research on person‐environment fit has paralleled that of other methods and constructs in psychology such as psychotherapy and social support. Initial efforts have focused on basic questions such as: “Does psychotherapy work?; What are the correlates of social support?; and Is fit good for you?” However, as research has accumulated, it becomes clear that the initial questions raised were too simple (Gottlieb, 1981; Kiesler, 1971). Like psychotherapy and social support, some kinds of fit may be good for some people, in some places, some of the time, and in some ways. The challenge for researchers in the area is the development of models and methods that capture more fully the richness of the transaction between person and environment.
Development of the design of fermenters with energy introduced by aerating gas, having contacting devices
Authors: Prokopenko V. D. , Viesturs U. E. 
Published: December 2004

AbstractThis paper deals with fermenters with energy introduced by gas phase (FG), having contacting devices, of laboratory, pilot and industrial scale.It is an attempt to state the possible use of such apparata in view of the rheological properties of the culture and intensity of mass transfer.There has been proved the necessity to introduce additional energy to speed up the circulation, determined by requirements of rational construction and definite demands set forth by the very process of microorganism cultivation (prevention of oxygen limitation, flotation, foam regulation etc.).
Characterization of biotechnological processes and products using high‐performance liquid chromatography (HPLC). I. Separations of carbohydrates, organic acids and lipids
Authors: Gey M. 
Published: December 2004

AbstractSuitable and optimized chromatographic separation systems for HPLC analyses of mono‐, di‐ and oligomeric carbohydrates, organic acids (e.g. gluconic acid, α‐ketoglutaric acid), phospholipids (PE, LPE, LPC, PC, SPH) and neutral lipids (squalene, cholesterol) are demonstrated.Applications of HPLC technique are separation examples of sugars from hydrolyzed starches which were isolated from potatos, calculations of organic acids in fermentation mediums and determinations of neutral lipids and phospholipids which were isolated from microbial biomass.The liquid chromatographic separations are based on self‐packed highly efficient (approximately 80 000 theoretical plates per meter, N/m) glass columns.
Influence of the mycelium growth conditions on the production of amylolytic, proteolytic and pectinolytic enzymes by Aspergillus niger C
Authors: Fiedurek J. , Ilczuk Z. , Łobarzewski J. 
Published: December 2004

AbstractVarious nitrogen and carbon sources, as well as natural products, were examined as inducers of the production of amylases, proteases and pectinases by A. niger C. A. niger C grown on wheat bran extract medium provided culture supernatants with the highest enzymatic activities. Some culture conditions, e.g. pH, medium temperature and time period of cultivation, were optimalized to improve the growth and enzymes biosynthesis by A. niger C.
Biochemical reactions of Brevibacterium flavum depending on medium stirring intensity and flow structure
Authors: Ruklisha M. P. , Vanags J. J. , Rikmanis M. A. , Toma M. K. , Viesturs U. E. 
Published: December 2004

AbstractAuthors have studied the dependence of the physiological and biochemical characteristics of lysine producers Brevibacterium flavum on medium stirring intensity upon constant pO2 during fermentation processes. Various factors affecting the rate of biochemical reactions in cells upon a changeable intensity of medium stirring in apparata with turbine stirrers; oxygen mass transfer intensity in the system; stirring characteristics in the fermenter; biochemical changes in the cells due to gradients of energy introduced by the stirrer in the fermenter, etc. have been studied. A comparison of the experimentally established values, characterizing macrostirring (e) and microstirring (KR), with the physiological and chemical characteristics of bacteria during fermentation made us suppose that the character of the kinetic energy distribution in the volume of fermenter is one of the factors regulating bacterial metabolism. Besides, there exists the value ecrit, upon which there can be observed essential changes of the physiological and biochemical properties of the cells. The effect of medium flows upon the cells is characterized by index Fstress, which takes into account both, the possible presence of the cells in the zone with e ≧ ecrit, and the degree of medium flow and cell interaction, numerically equal to value (e – ecrit)0.5.
Microorganisms for lipids
Authors: Ratledge C. 
Published: December 2004

AbstractMicro‐organisms have often been considered for the production of oils and fats as an alternative to agricultural commodities. However, with the continuing low cost of agricultural production of oil‐seeds, biotechnology has little to offer in the way of competition against such items as soybean oil, groundnut oil, and even polyunsaturated oil such as sunflower oil even though good facsimiles of these oils could be produced. It is now clear that if we are to use microorganisms to produce lipids, i.e. Single Cell Oil, then these must be highly specific ones which are currently expensive to obtain from agricultural sources. In particular, the possible production of a cocoa‐butter substitute using mutated yeast cells is reviewed here as well as the production of highly polyunsaturated fatty acids (PUFAs) using various species of mould. With regard to producing a cocoa‐butter equivalent fat, it is necessary to identify not only a cheap carbon source on which the yeast may grow (this is now considered likely to be lactose arising from whey) as well as deriving a mutant strain of the yeast which will accumulate large amounts of stearic acid within the oil. The recent work carried out in The Netherlands and New Zealand to achieve these goals is described. With regard to polyunsaturated fatty acid production, various prospects exist and indeed, the commercial production of one acid, gamma‐linolenic acid, is now being produced commercially in both the U.K. and Japan. The background work leading to this product is described and opportunities for other PUFAs being produced biotechnologically are discussed.
Aggregation kinetics of saccharomyces cerevisiae on solid surfaces
Authors: Schmidt R. 
Published: December 2004

AbstractIn the colonization experiments of yeast cells on stainless steel surfaces the analyzed minimum of the colonization rate was found in a roughness interval between a highly polished sample and a very rough surface. This phenomenon is a problem of the shear forces and of adhesion.On the basis of reaction kinetics it was possible to analyze the change between an unstable and a stable cell‐cluster. The analysis of the energy needed for forming a stable cluster tends toward values known from the stochastic simulation of cluster formation in an undisturbed region. But the potential function is not clear which describes the interactions between the cells and the forming cluster in the reaction field. This is a problem of special materials‐testing which is not established.For producing plants it is of high interest to note that it are not the most highly polished surfaces that are the best.
Application of vesicle chromatography in protein purification
Authors: Kleine R. , Woehlecke H. , Ehwald R. 
Published: December 2004

AbstractA recently described vesicular packing material (VP) representing clusters of microcapsules (derived from plant cells) was tested with respect to its application for protein purification. Protein elution behaviour was investigated with 28 defined proteins and several protein containing preparations and biological fluids. All proteins were eluted with a neutral buffer without retardation as peaks in the permeable or excluded fraction. Due to its sharp separation limits VP can be used for the separation of proteins with small differences in size. In special cases, proteins of nearly equal molecular weight (e.g. carboxypeptidase A and pepsin) may be separated due to differences in the electrical charge of the protein molecules and resulting differences in the electric in the electrical charge of the protein molecules and resulting differnces in the electric interaction with the negatively charged polygalacturonan matrix of the vesicle membrane (cell wall).Vesicle chromatography is a biocompatible process. The VP may be applied on a large scale. Complete separation between excluded and permeable proteins may be reached if the columns are loaded with concentrated protein samples (e.g., blood plasma). Size fractionation by the VP seems to be applicable in the following fields:

Preparative separation of an excluded protein from an excess of permeable macromolecules, especially if the difference in STOKES' diameter is too small for an effective separation by gel chromatography or conventional membrane techniques.
Preparative separation of permeable proteins from an excess of excluded proteins.
Chromatography of proteins in the presence of alcohol, polyethylene glycol or detergents.
Biosynthesis, preparation and properties of ascochitine
Authors: Foremska E. , Kostecki M. , Chełkowski J. 
Published: December 2004

AbstractThis paper is concerned with the biosynthesis of a high yield of mycotoxin ascochitine by a Ascochyta pisi strain ATCC 66101 on solid substrate with a description of the subsequent procedure of extraction, purification and crystallization. Spectroscopic, chromatographic and antibiotic properties of the mycotoxin are reported.
Fixation of thermostable β galactosidase on zeolithes with controlled hydrophobicity
Authors: Zentgraf B. , Gwenner C. 
Published: December 2004

AbstractThermostable and hydrophobic β galactosidase of Bacillus sp. TP32 is fixed on zeolithes of controlled hydrophobicity. Thereby, the Si/Al ratio of the zeolithe is an important quantity for controlling the zeolithe hydrophobicity and with it the rate and efficiency of enzyme fixation. The fixation properties improve from NaY via Us(w) to mordenite and Us‐Ex.Mordenite β galactosidase is highly active in SOERENSEN phosphate buffer, dodecanole, and ethylene glycole at 70°C using ortho nitrophenyl β D‐galactopyranoside (ONPG) as substrate. Further preparations of zeolithe β galactosidase have more or less disadvantages in regard to hydrolysis of ONPG at elevated temperature, as well as rate and efficiency of enzyme fixation exept of Us‐Ex β galactosidase in ONPG‐containing dodecanole.
Determination of the best nutrient medium for the production of L‐lactic acid from beet molasses a statistical approach
Authors: Monteagudo J. M , Rincón J. , Rodríguez L. , Fuertes J. , Moya A. 
Published: December 2004

AbstractOptimization studies have been carried out for the production of L‐lactic acid from the fermentation of beet molasses by Lactobacillus delbrueckii. A PLACKETT‐BURMAN Design and a Central Composite Design have been used to determine the most suitable nutrient medium for obtaining a maximum cell concentration. A second‐order polynomial empirical model relating both the cell and nutrient concentrations was formulated. The variables selected for the study were Yeast Extract, Peptone, Tween 80 (antifoam), MgSO4 · 7H2O, MnSO4·4H2O, FeSO4 · 7H2O and K2HPO4/KH2PO4. Among them, only Yeast Extract and Peptone were found to significantly affect the cell concentration. A maximum cell yield was found when the concentrations of Yeast Extract and Peptone were, respectively, 5.31 g/l and 5.08 g/l. All conclusions are restricted to the experimental range studied.
Lipid production and fatty acid composition of selected strains belonging to Mucorales
Authors: Čertík M. , Berhan S. Sereke , Šajbidor J. 
Published: December 2004

AbstractThe lipid accumulation, fatty acid composition and γ‐linolenic acid (GLA) production by 28 strains belonging to Mucorales were investigated. The lipid content varied from 5 to 30% on dry biomass and the percentage of γ‐linolenic acid in total intracellular lipid was in a range from 2.5 to 15.4% (w/w). The best yield of γ‐linolenic acid (expressed as mg GLA per 1 g biomass) was found for Mucor mucedo CCF – 1384 (28.4) and Cunninghamella echinulata CCF – 103 (25.1).
Production of oxytetracycline and rifamycins B and SV with cells immobilized on glass wool
Authors: Farid M. A. , El Diwany A. I. , El Enshasy H. A. 
Published: December 2004

AbstractThe antibiotic producing microorganisms Streptomyces rimosus PFIZER 18234‐2 and Amycolatopsis mediterranei CBS 42575 were immobilized in glass wool for the production of oxytetracycline and rifamycins B and SV. The growth of the immobilized cells was dependent on the type of the microorganism and on the amount of glass wool as well. After 5 exchanges of the medium, 530 mg O.T.C., 2138 mg rifamycin B and 8672 mg rifamycin SV were maintained. The periodic batch culture was continued for 20 days.
Extracellular amylase synthesis by Bacillus globisporus BH‐1b
Authors: Bandyopadhyay A. , Sen S. K. , Pal S. C. 
Published: December 2004

AbstractDespite the prevalence of starch‐hydrolyzing enzymes in bacilli, relatively few have been studied in detail. In an attempt to isolate an effective α‐amylase‐producing strain, Bacillus globisporus BH‐1b has been isolated. The strain requires few nutritional supplements and shows induction in the presence of galactose. 2% potassium nitrate and pH 7.2 emerged as optimum for the fermentation medium. The durability of the enzyme has also been tested at a low pH and a high temperature.
Behaviour of Candida utilis during growth in relation to Mg2+ and K+ concentration in sugar cane molasses
Authors: Otero M. A. , Reyes A. 
Published: December 2004

AbstractMagnesium and potassium ions are present in sugar cane molasses in a concentration of about 0.3% and 2.5%, respectively, which is high enough to support biomass production from Candida utilis. Culture broth with 40 g/l of total reducing substances supplemented by the addition of 1 ppm of Mg2+ leads to a higher yield (Y x/s) in batch fermentation experiments. The subsequent addition of Mg2+ up to 10 ppm decreases the yield coefficient from 0.53 to 0.42 without affecting the growth rate. Fermentation media supplemented with 1 to 10 ppm of K+ decreased both the yield coefficient and the specific growth rate. A Mg/K ratio of about 0.1 seems to be optimal for yeast biomass propagation.
Transformation of ferulic acid by soil bacteria Nocardia provides various valuable phenolic compounds
Authors: Malarczyk E. , Rogalski J. , Leonowicz A. 
Published: December 2004

AbstractNocardia autotrophica was grown in a medium containing ferulic acid and 14C‐ferulic acid, labelled in various parts of a particle as a main carbon source. After incubation, the products were analyzed by thin layer, high performance liqid and gas chromatography and by IR and NMR spectra methods. The products detected were caffeic acid, catechol, coniferyl alcohol, eugenol, guaiacol, hydrocaffeic acid, isoeugenol, isoferulic acid, isovanillic acid, p‐hydroxybenzoic acid, protocatechuic acid and aldehyde, vanillic acid, and vinylguaiacol. A liberation of 14CO2 during cultivation was noticed.
Aerobic degradation of toluene in a closed chemostat with and without a head space outlet
Authors: Ray P. , Löser C. 
Published: December 2004

AbstractThe present paper describes the continuous aerobic cultivation of a Pseudomonas strain with toluene as the substrate in a closed chemostat with oxygen or air as the gas phase. Due to the constant supply of a nitrogen‐saturated aqueous medium, nitrogen passes from the liquid phase of the chemostat into the gas phase (head space). This results in an increasing nitrogen content (asymptotic approach to 100%). The concomitant decrease in the partial pressure of the oxygen in the gas phase finally leads to an oxygen limitation for the bacteria in the medium and an incomplete toluene degradation. The critical nitrogen content of the gas phase at which oxygen limitation begins depends on the toluene concentration in the incoming medium. However, when the gas is continuously removed from the head space, the nitrogen content reaches a steady‐state value of less than 100%, depending on the flow rate of the outgoing gas. The oxygen limitation and the associated incomplete toluene degradation can be prevented in this way. The method of gas removal from the head space to avoid oxygen limitation is also applicable when the reactor is supplied with air instead of oxygen. Waste waters contaminated with highly volatile pollutants can thus be biologically decontaminated under aerobic conditions, without shifting the pollution problem from the liquid to the gas phase.