bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regioselectivity of 5, 6, 7, 8‐Tetrafluoroquinoline and 6‐X‐Trifluoroquinoline (X = CF3, H) in Reactions with Nucleophiles
Authors: Panteleeva Elena V. , Shteingarts Vitalij D. , Grobe Joseph , Krebs Bernt , Triller Michael U. , Rabeneck Helmut 
Published: June 2004

AbstractA systematic study of the direction of nucleophilic attack of the nucleophiles Me3MEMe2 (M = Si, Sn; E = P, As), NaOMe, LiR (R = Me, nBu, Ph) and PhMgBr on 5, 6, 7, 8‐tetrafluoroquinoline (1), 6‐CF3‐5, 7, 8‐trifluoroquinoline (2) and 5, 7, 8‐trifluoroquinoline (3) was performed with the aim to develop synthetic routes to specific functional derivatives and to gain a deeper insight into the mechanisms governing the regioselectivity. With the fairly “soft” nucleophiles Me3MEMe2 in general mixtures of 7‐Me2EC‐(main product) and 6‐Me2EC‐derivatives (side product) are formed (Schemes 1, 2, 4). Sulfuration of the isomer mixtures with E = P yields mixtures of the corresponding thiophosphano derivatives. The observed regioselectivity is explained by a concerted action of two factors: (i) The influence of the heteroatom N on the stabilization of the σ‐complex type transition states and (ii) the collective effect of four fluorine substituents favouring 6‐ and 7‐substitution. — The reaction of 1 with sodium methoxide (Scheme 3) was carried out to test the early conclusion on the exclusive formation of 7‐methoxy‐5, 6, 8‐trifluoroquinoline (14) [2], made on the basis of a GC‐analysis. For that purpose the molar ratio 1 : MeO— was varied from 1 : 1.25 over 1 : 1 to 1 : 0.5. — In the reactions of the quinoline precursors 1—3 with the organometallic reagents LiR (R = Me, nBu, Ph) and PhMgBr (Scheme 5) products of the nucleophile‐addition at position 2 were obtained in high yields, which with hydrochloric acid led to 2‐R‐1, 2‐dihydro‐5, 6, 7, 8‐tetrafluoroquinolines. In contact with air or by reaction with MnO2, oxidation to aromatic 2‐R‐5, 6, 7, 8‐tetrafluoroquinolines occurred. To rationalize the observed differences between the “soft” Me3MEMe2 and the “hard” carbon‐centred nucleophiles, two different hypothetic mechanisms are discussed. Since most of the compounds have been obtained in reaction mixtures, the assignment to structural formulae is mainly based on GCMS and CMS analyses together with 1H‐, 19F‐ and 31P NMR data and comparison with literature information and with spectra registered for individual compounds. In addition, the molecular structures of the representatives 6, 20 and 29, determined by X‐ray analyses, prove the structural formulae deduced from the spectra of products.
Polysulfonylamine. CLX [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 10 [2] Die dreidimensionalen Koordinationspolymere M[(CH3SO2)2N] mit M = Kalium, Rubidium, Caesium (isotype Strukturen für M = K, Rb)
Authors: Moers Oliver , Latorre Violeta , Nagel Karl‐Heinz , Blaschette Armand , Jones Peter G. 
Published: June 2004

AbstractEs werden Tieftemperatur‐Röntgenstrukturen mitgeteilt für KA (monoklin, Raumgruppe P21/c, Z′ = 1), RbA (isotyp und isostrukturell mit KA) und CsA (monoklin, P21/n, Z′ = 1), wobei A— das Anion der starken Stickstoffsäure (MeSO2)2NH bezeichnet. In KA und RbA hat das Anion eine seltene C1‐Konformation, in CsA die Standardkonformation mit zweizähliger Symmetrie. Sämtliche Strukturen beruhen auf dreidimensionalen Koordinationsnetzwerken, in welchen die Kationen durch Wechselwirkungen mit einem (O, N)‐ und einem (O, O)‐chelatisierenden sowie drei κ1 O‐bindenden Anionen eine unregelmäßige (O6N)‐Heptakoordination erreichen; darüber hinaus erhöht sich die Koordinationszahl des Cs+‐Ions infolge eines sehr kurzen (Cs···Cs)‐Kontaktabstands von 422, 5 pm auf den effektiven Wert acht. Die Kristallpackungen der isotypen Verbindungen KA und RbA weisen substrukturelle lamellare Schichten auf; diese bestehen aus einer inneren Kationlamelle sowie Anion‐Monoschichten als äußeren Umhüllungen und werden von sechs unabhängigen Ligand‐Metall‐Bindungen zusammengehalten, während die letzte unabhängige M—O‐Bindung die Schichten zur endgültigen 3D‐Struktur quervernetzt. Im Gegensatz dazu existieren in der Packung von CsA zickzackförmige planare Kationketten (Cs···Cs alternierend 422, 5 und 487, 5 pm, Cs···Cs···Cs 135, 7°); die Ketten sind zwischen Anion‐Monoschichten in der Weise intercaliert, daß jede von vier Anionstapeln umgeben und koordiniert wird und jeder Anionstapel zwei Kationketten miteinander verknüpft. In allen Strukturen treten schwache Wasserstoffbrücken des Typs C—H···A auf.
Synthesis and Molecular Structure of [n‐Bu2(F)SnOSn(F)t‐Bu2]2 — an Unsymmetrically Substituted Tetraorganodistannoxane
Authors: Beckmann Jens , Dakternieks Dainis , Duthie Andrew , Jurkschat Klaus , Schürmann Markus 
Published: June 2004

AbstractThe dimeric tetraorganodistannoxane [n‐Bu2(F)SnOSn(F)t‐Bu2]2 (1) was prepared by the reaction of (t‐Bu2SnO)3 with n‐Bu2SnF2 and characterized in solution by multinuclear NMR spectroscopy and ESI MS spectrometry and in the solid state by 119Sn MAS NMR spectroscopy and single crystal X‐ray diffraction.
Molekül‐ und Kristallstruktur von Quecksilber(II)‐α‐Amino‐γ‐methylmercapto‐butyrat, Hg(Met)2
Authors: Meyer Gerd , Nolte Matthias 
Published: June 2004

AbstractMolecular and Crystal Structure of Mercuric α‐Amino‐γ‐methyl‐mercapto‐butyrate, Hg(Met)2The mercuric salt of deprotonated methionine, Hg(Met)2, was obtained as colourless needles from aqueous solutions of methionine and HgCl2 or HgO, respectively. The crystal structure (monoclinic, P21, Z = 2, a = 984, 2(2), 507, 96(6), c = 1574, 2(3) pm, β = 93, 05(2)°; Rall = 0, 055) exhibits formula‐like molecules with strong Hg—N coordination at a distance of 216 pm; one oxygen atom adds to a chelate like N—Hg—O coordination. Stacking of these molecules adds two oxygen atoms of different methionate anions to an effective 2+2+2 „octahedral”︁ coordination around the mercuric ion. Thereby a layer structure parallel (001) is formed with the methyl‐mercapto function on top and bottom of these layers.
Stridulation variability and morphology: an examination in dung beetles of the genus Trypocopris (Coleoptera, Geotrupidae)
Authors: Carisio Loredana , Palestrini Claudia , Rolando Antonio 
Published: June 2004

AbstractDistress signals produced by dung beetles of the genus Trypocopris (Coleoptera, Geotrupidae) were analysed to test whether interspecific and intraspecific acoustic variability are species‐ and subspecies‐specific and to ascertain to what extent bioacoustic parameters depend upon the morphology of the stridulatory organs (pars stridens). Bioacoustic analyses showed that the three species were clearly differentiated, despite the fact that disturbance stridulations presented the same stereotyped spectrographic pattern. Within each species, most of the subspecies and populations considered were also bioacoustically distinguishable. Subspecies and populations within each species were differentiated with regard to body size and stridulatory organ, and the length of the pars stridens was positively correlated with the width of the coxa, in turn positively correlated with body size. A few spectrographic measures were significantly constrained by the morphology of the stridulatory apparatus; in particular the duration of sound emission was positively correlated with the length of the apparatus and the sub‐pulse rate was negatively related to the distance between two consecutive crests. For T. pyrenaeus, with the largest number of populations sampled, there was no significant correlation between morphological and spectrographic distances, but there were significant positive correlations between morphological and geographical distances and between morphological and genetic distances. It is hypothesized that genetic differentiation might directly affect variability of the stridulatory apparata which would also be indirectly influenced and constrained by external morphological traits (like the width of the coxa and body size). Stridulatory organs, in turn, would affect the ways a few stridulatory traits (especially the temporal ones) change in time and space.
A new hypothesis for species coexistence: male–male repulsion promotes coexistence of competing species
Authors: Mikami Osamu K. , Kohda Masanori , Kawata Masakado 
Published: June 2004

AbstractWe propose a new hypothesis for species coexistence by considering behavioral interactions between individuals. The hypothesis states that repulsive behavior between conspecific males (male–male repulsion) creates space for competing species, which promotes their coexistence. This hypothesis can explain the coexistence of two competing species even when their ecological niches completely overlap in spatially homogeneous environments. In addition, the mechanisms underlying such behavior might play a role in enabling the coexistence of two species immediately after speciation, with little or no niche differentiation, as in the case of cichlid fish communities, for example. Although there is limited evidence supporting this hypothesis, it can nevertheless explain the occurrence of species coexistence and biodiversity, which cannot be explained by previous theories.
Automated Optimization of Aptamer Selection Buffer Conditions
Authors: Stovall Gwendolyn M. , Cox J. Colin , Ellington Andrew D. 
Published: June 2004

Optimizing the buffer conditions of the selection of nucleic acid binding species (aptamers), increases the likelihood of producing a target aptamer. Aptamers, with high target affinity and specificity, are often compared to antibodies, as aptamers emerge in the industry as diagnostic and therapeutic tools. The increased demand for aptamers encourages high-throughput aptamer generation. The selection buffer conditions may vary as widely as the selection targets, and therefore buffer optimization is helpful if not required for effective aptamer selections. Such optimization work is time consuming and repetitious, which bodes well for high-throughput applications. To accommodate this, an automated buffer testing protocol has been developed to test target-to-unselected RNA pool binding in the presence of 96 different buffer conditions. The dynamic program may vary the monovalent salt(s) identity, monovalent salt(s) concentration, divalent salt(s) identity, divalent salt concentration, buffer identity, buffer concentration, and pH. The optimized buffer conditions likely increase the probability of a successful selection and therefore promote higher ratios of successful aptamer selections against a variety of targets. Preliminary results show trends with the buffer matrix solutions and lysozyme:unselected pool binding. In general, an inverse relationship between lysozyme binding and monovalent salt concentration is observed. (JALA 2004;9:117-22)
Mechanical differences between lumbar and tail discs in the mouse
Authors: Sarver Joseph J. , Elliott Dawn M. 
Published: June 2004

AbstractThe mouse lumbar and tail discs are both used as models to study disc degeneration; however, the mechanical behavior of these two levels has not been compared. The objective of this study was to compare the elastic and viscoelastic mechanical properties of lumbar and tail discs of the mouse under axial compression–tension loading. We hypothesized that tail discs would have a larger transition zone (e.g., neutral zone) and would be less stiff in compression. To test these hypotheses, lumbar and tail bone–disc–bone motion segments were loaded in axial compression and tension. The nonlinear elastic mechanical behavior was examined using a tri‐linear curvefit. Elastic behavior of lumbar and tail discs was most different in the low‐stiffness transition region (neutral zone), where lumbar discs were nearly twice as stiff over half the axial displacement. In addition, viscoelastic behavior, which was examined using a stretch–exponential curvefit, also showed large lumbar and tail differences, where lumbar discs compressed by 60% of their original height and tail discs by 98% after static creep compression. These results demonstrate that tail discs undergo far more axial displacement than lumbar discs under the same load. These findings are relevant to rodent tail models where chronic loads are applied in vivo to study mechanical pathways of degeneration. Furthermore, the tri‐linear model, used here to curvefit the nonlinear compression–tension data, quantified stiffness in the transition zone for the first time, which may prove useful in future disc mechanical studies. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Growth factor induced fibroblast differentiation from human bone marrow stromal cells in vitro
Authors: Moreau Jodie E. , Chen Jingsong , Bramono Diah S. , Volloch Vladimir , Chernoff Herman , Vunjak‐Novakovic Gordana , Richmond John C. , Kaplan David L. , Altman Gregory H. 
Published: June 2004

AbstractUtilizing a two‐dimensional tissue culture plastic screening system and a fractional factorial design, specific media formulations and growth factor combinations were determined that support human bone marrow stromal cell (BMSC) differentiation toward fibroblast characteristics for utilization in tissue engineering, specifically cell morphology and alignment, metabolic activity, abundant expression of collagen types I and III, and negligible expression of other tissue‐specific markers. BMSCs were cultured for up to 14 days on tissue culture plastic, supplemented with Dulbecco's Minimal Essential Medium (DMEM)/10% FBS or Advanced DMEM(ADMEM)/5% FBS. Each medium base was supplemented with one of nine possible growth factor combinations and ascorbate‐2‐phosphate (Asc‐2‐P) for the duration of culture. ADMEM supported comparable cell viability with half the serum content of the DMEM formulation. Asc‐2‐P was potent in promoting BMSC proliferation, in the absence of a mitogen, supporting significant increases in cell activity over 14 days of culture. DMEM promoted significant increases in cell viability for 7 of 9 growth factor groups when compared to their ADMEM counterparts. ADMEM, however, promoted increased cell transcript and protein expression, as 5 of 9 growth factor combinations induced a 200% increase in collagen type I versus equivalent DMEM cultures. Cell morphology and collagen type I immunostaining, when assessed in context of MTT and RNA results, identified 3 growth factor and medium combinations that supported fibroblast differentiation for future development of ligament tissue in vitro. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Sources of Registration Error with Image Guidance Systems During Endoscopic Anterior Cranial Base Surgery
Authors: Snyderman Carl , Zimmer Lee A. , Kassam Amin 
Published: June 2004

OBJECTIVESThe goal of this study was to evaluate the accuracy of the registration process and to identify potential sources of error during anterior cranial base surgery.STUDY DESIGN AND SETTINGThe registration accuracy of image guidance and the location of excluded fiducials were recorded prospectively from 50 endoscopic, anterior cranial base procedures in an academic university setting.RESULTSThe mean error of initial registration was 2.8 mm (range, 1.4 to 7.1 mm). Following the exclusion of fiducials the mean error of registration was 1.6 mm (range, 0.6 to 3.7 mm). There was a significant improvement in the mean error rate from initial to final registration following the exclusion of fiducials (P < 0.0001). Posterior fiducials were excluded most often and anterior fiducials were excluded the least. Registration accuracy was similar for CT and MRI (P = 0.64).CONCLUSIONSThe accuracy of the Stryker Image Guidance System is enhanced by the exclusion of individual fiducials with high registration errors.SIGNIFICANCEThe exclusion of fiducials with high registration errors increases the accuracy of image guidance in anterior cranial base surgery.
A New Measure of Placebo Response and Patient Satisfaction in Office Encounters
Authors: Ovchinsky Alexander , Ovchinsky Nadia , Rosenfeld Richard M. 
Published: June 2004

OBJECTIVESPlacebo response is defined as a change in health status resulting from the symbolic significance attributed by the patient or proxy to the physician encounter. Our goals were to validate the PR12 survey as a measure of placebo response and to analyze the placebo response as a discrete and measurable component of everyday office encounters with the otolaryngologist.STUDY DESIGNThis was a prospective, before‐and‐after clinical outcomes study of 95 children aged 6 months to 12 years conducted in an academic metropolitan pediatric otolaryngology practice. Caregivers completed the PR‐12 survey at entry and at least 4 weeks later. The survey included 3 domains (4 questions each) reflecting the main components of the placebo response: meaningful explanation, care and concern, and mastery and control. PR‐12 was correlated with longitudinal change in health status at least 1 to 2 months after the baseline visit. Outcome measures included direct and indirect measures of change in disease‐specific quality of life and satisfaction with change.RESULTSTest‐retest reliability was fair for most PR‐12 survey items (R = 0.41 to 0.76) but was higher for domains (0.60 to 0.66) and the overall survey score (0.66). PR‐12 had excellent internal consistency (Cronbach's alpha 0.91) and appropriate construct validity. Caregiver satisfaction change at follow‐up correlated with the PR‐12 (r = ‐.25, P = 0.036). Conversely, no correlation was seen between the PR‐12 and direct and indirect measures of change in disease specific quality of life.CONCLUSIONPlacebo response is an important and potentially measurable aspect of clinical encounters. PR‐12 is a promising first step at creating a brief, reliable, and valid instrument to assess the placebo response.SIGNIFICANCEReemphasizing the therapeutic potential of the doctor‐patient relationship may improve quality of care and disease outcomes.
Anatomic Limitations of Posterior Exposure of the Sinus Tympani
Authors: Aslan Asim , Guclu Gulay , Tekdemir Ibrahim , Elhan Alaittin 
Published: June 2004

OBJECTIVEThe sinus tympani is a challenging area for the otologic surgeon to access and from which to remove the disease process. Recently, a posterior approach to the sinus tympani through the mastoid was proposed as an alternative technique in cases of deep sinus tympani.STUDY DESIGN AND SETTINGThe posterior approach was performed by dissecting the triangular bony area formed by the facial nerve, lateral semicircular canal, and posterior semicircular canal in 8 temporal bone specimens.RESULTSThe edges of the triangle on the facial nerve and lateral semicircular canal were almost constant at 5 mm. The edge on the posterior semicircular canal was about 4 mm.CONCLUSIONIt is possible to expose the sinus tympani from the posterior by careful dissection through this triangle, which has almost constant dimensions.
A History of Failures and Miscalculations? Britain's Relationship to the European Communities in the Postwar Era (1945–1973)
Authors: CLEMENS GABRIELE 
Published: June 2004

Alan S. Milward, The Rise and Fall of a National Strategy 1945–1963 (The United Kingdom and The European Community, Vol. I) (London and Portland: Frank Cass, 2002), 512 pp., £65.00 (hb), ISBN 0-7146-5111-7.Alex May, ed., Britain, the Commonwealth and Europe: The Commonwealth and Britain's Applications to Join the European Communities (Houndsmill and New York: Palgrave, 2001), 188 pp., £55.00 (hb), ISBN 0-333-80013-3.Oliver J. Daddow, ed., Harold Wilson and European Integration. Britain's Second Application to Join the EEC (London and Portland: Frank Cass, 2003), 298 pp., £45.00 (hb), ISBN 0-7146-5222-9, £17.50 (pb), ISBN 0-7146-8207-1.Sir Con O'Neill, Britain's Entry into the European Community. Report by Sir Con O'Neill on the Negotiations of 1970–1972, ed. and with a foreword by Sir David Hannay (London and Portland: Frank Cass, 2000), 464 pp., £55.00 (hb), ISBN 0-7146-5117-6.
Everyday Communism: New Social History of the German Democratic Republic
Authors: KOTT SANDRINE 
Published: June 2004

Konrad Jarausch, ed., Dictatorship as Experience. Toward a Socio-Cultural History of the GDR (New York and Oxford: Berghahn Books, 1999), 388 pp., £14.00 (pb), ISBN 1-57181-182-6.Thomas Lindenberger, ed., Herrschaft und Eigensinn in der Diktatur (Cologne, Weimar and Vienna: Böhlau Verlag, 1999) 367 pp., €39.90 (hb), ISBN 3-412-13598-4.Annegret Schüle, ‘Die Spinne’. Die Erfahrungsgeschichte weiblicher Industriearbeit im VEB Leipziger Baumwollspinnerei (Leipzig: Leipziger Universitätsverlag, 2001), 398 pp., €18.00 (pb), ISBN 3-934565-87-5.Patrick Major and Jonathan Osmond, eds., The Workers' and Peasants' State. Communism and Society in East Germany under Ulbricht 1945–71 (Manchester: Manchester University Press, 2002), 272 pp., £15.99 (pb), ISBN 0-7190-6289-6.Joshua Feinstein, The Triumph of the Ordinary. Depictions of Daily Life in the East German Cinema 1949–1989 (Chapel Hill: University of North Carolina Press, 2002), 331 pp., £19.50 (pb), ISBN 0-8078-5385-2.
Impact of horizontal model resolution and orography on the simulation of a western disturbance and its associated precipitation
Authors: Dimri A. P. 
Published: June 2004

AbstractA nonhydrostatic version of Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Model (MM5) is used to study the effects of the horizontal model resolution and orography while simulating an active western disturbance (WD) that affected northwest India from 21 to 25 January 1999. Two numerical experiments are conducted with six combinations of two factors: horizontal model resolution and topography. National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysed data are used for the initial and boundary conditions. Simulation results indicate that the distribution and the rate of simulated precipitation due to a WD over northwest India is highly sensitive to the horizontal model resolution and topography. The model with finer resolution (30 km) is better able to estimate effects of mesoscale forcing on precipitation over the selected domain. The amount of precipitation simulated over the coarse domain is much less than the observed precipitation owing to the model's unrealistic representation of orographic effects and mesoscale forcing. Simulated terrain, vertical velocity, wind and streamline at different horizontal model resolutions are presented. The detailed structure and distribution of wind speed are simulated in the finer domain. Simulated vertical velocity and precipitation are less in the second experiment when a flat topography is used across the domain, which indicates that topography plays a significant role in modulating the WD. Sensitivity of the horizontal model resolution for precipitation is assessed and it is found that the finer domain of the model simulation gives better results. Copyright © 2004 Royal Meteorological Society.
Pharmacotherapies for problematic psychostimulant use: a review of current research
Authors: SHEARER JAMES , GOWING LINDA R. 
Published: June 2004

AbstractThis review summarizes the current status of clinical research on pharmacotherapies for problematic psychostimulant use. The use of psychostimulants, including amphetamine, cocaine and ecstasy, is increasingly a feature of Australian life as is the presentation of patients with psychostimulant disorders. A lack of experience, resources and treatment options have constrained the response of treatment services to such problems. Despite extensive research, particularly in the area of cocaine, no pharmacotherapy has been proven effective in the management of psychostimulant disorders. The harms associated with problematic psychostimulant use warrant further controlled research in innovative approaches integrated with psychosocial interventions.