bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring proteasome complexes by proteomic approaches
Authors: Drews Oliver , Zong Chenggong , Ping Peipei 
Published: March 2007

AbstractThe ubiquitin proteasome system (UPS) represents a major pathway for intracellular protein degradation. Proteasome dependent protein quality control participates in cell cycle, immune response and apoptosis. Therefore, the UPS is in focus of therapeutic investigations and the development of pharmaceutical agents. Detailed analyses on proteasome structure and function are the foundation for drug development and clinical studies. Proteomic approaches contributed significantly to our current knowledge in proteasome research. In particular, 2‐DE has been essential in facilitating the development of current models on molecular composition and assembly of proteasome complexes. Furthermore, developments in MS enabled identification of UPS proteins and their PTMs at high accuracy and high‐throughput. First results on global characterization of the UPS are also available. Although the UPS has been intensively investigated within the last two decades, its functional significance and contribution to the regulation of cell and tissue phenotypes remain to be explored. This review recapitulates a variety of applied proteomic approaches in proteasome exploration, and presents an overview of current technologies and their potential in driving further investigations.
Analysis of mouse skin reveals proteins that are altered in a diet‐induced diabetic state: A new method for detection of type 2 diabetes
Authors: List Edward O. , Berryman Darlene E. , Palmer Amanda J. , Qiu Linghua , Sankaran Sudha , Kohn Doug T. , Kelder Bruce , Okada Shigeru , Kopchick John J. 
Published: March 2007

AbstractIn this study, proteomic analysis was performed on the skin of C57BL/6J mice with type 2 diabetes and compared to nondiabetic controls. To induce obesity and subsequent diabetes, mice were placed on a high‐fat diet for 16 wk. After 16 wk, both diabetic and nondiabetic control mice were sacrificed and their skin removed for analysis. Following 2‐DE, proteomic profiles from the skin samples were quantified using PDQuest software. Out of more than 1000 distinct protein spots, 28 were shown to be significantly altered with 6 being decreased and 22 increased in the diabetic state compared to controls. The 28 protein spots were removed from the gels and analyzed by MALDI‐TOF and MS/MS analyses. Protein identifications revealed that 17 of the 28 proteins were involved in energy metabolism (60.7% of changes observed). Collectively, none of the significantly altered proteins had been shown previously to be altered in diabetic skin. This study not only helps to identify proteins found in skin samples of obese mice with type 2 diabetes, but also shows that skin biopsies coupled with proteomic analysis may be useful as a noninvasive method for the diagnosis of hyperinsulinemia and diabetes.
Proteome analysis of Rickettsia felis highlights the expression profile of intracellular bacteria
Authors: Ogawa Motohiko , Renesto Patricia , Azza Saïd , Moinier Danielle , Fourquet Patrick , Gorvel Jean‐Pierre , Raoult Didier 
Published: March 2007

AbstractThe proteome of Rickettsia felis, an obligate intracellular bacterium responsible for spotted fever, was analyzed using two complementary proteomic approaches: 2‐DE coupled with MALDI‐TOF, and SDS‐PAGE with nanoLC‐MS/MS. This strategy allowed identification of 165 proteins and helped to answer some questions raised by the genome sequence of this bacterium. We successfully identified potential virulence factors including two putative adhesins, four proteins of the type IV secretion system, four Sca autotransporters, four components of ABC transporters, some R. felis‐specific proteins, and one antitoxin of the toxin‐antitoxin system. Notably, the antitoxin was the first to be identified in intracellular bacteria. Only one protein containing rickettsia palindromic repeats was found, whereas none of the split genes, transposases, or tetratricopeptide/ankyrin repeats were detectably expressed. Comparison of the protein expression profiles of R. felis and 23 other bacterial species according to functional categories showed that intracellular bacteria express more proteins related to translation, especially ribosomal proteins. However, the remaining bacteria express more proteins related to energy production and carbohydrate/amino acid metabolism. In conclusion, this study reveals R. felis virulence factor expression and highlights the unique protein expression profile of intracellular bacteria.
Addition, elimination, exchange, and epimerization in nitro sulfones
Authors: Kingsbury Charles A. , Weinhold Jon , Winter Jeremy 
Published: March 2007

AbstractThree reactions were studied in the diastereomers of 1‐(benzenesulfonyl)‐2‐nitro‐1‐phenylpropane (1A and 1B) and briefly in related compounds: elimination of the benzenesulfonyl group, epimerization of one diastereomer to the other, and deuterium/hydrogen exchange at the methine group next to nitro in starting material. The two diastereomers showed quite different reactivity. The high melting diasteromer showed rapid elimination and some exchange. The low melting diastereomer (at approximately a half‐life) showed extensive epimerization, and elimination to the alkene, but little exchange. There is little effect of aromatic substituents on reaction course. The situation is complicated by re‐addition of benzenesulfinate to the alkene. The addition reaction was similar to elimination in agreement with the Principle of Microscopic Reversibility expectations. An electron transfer mechanism for addition is calculated to be comparatively favorable. Copyright © 2007 John Wiley & Sons, Ltd.
Kinetic and mechanism of the homogeneous, unimolecular elimination ofα,β‐unsaturated aldehydes in the gas phase
Authors: Chabán Omar Y. , Domínguez Rosa M. , Herize Armando , Tosta María , Cuenca Angela , Chuchani Gabriel 
Published: March 2007

AbstractThe gas phase thermal decarbonylation ofα,β‐unsaturated aldehydes E‐2‐butenal and E‐3‐phenyl‐2‐methylpropenal was studied in a static system over the temperature range 380.5–490.0 °C and pressure range 55.5–150 Torr. The reactions are homogeneous and unimolecular and obey a first‐order rate law. The rate coefficient is represented by the following Arrhenius equations:The elimination products of 2‐butenal are propene and CO gas, while 3‐phenyl‐2‐methylpropenal producesα‐methylstyrene,cis‐trans‐β‐methylstyrene, indan, and CO gas. Kinetic and thermodynamic parameters suggest these elimination reactions to proceed through a three‐membered cyclic transition state type of mechanisms. However, a two steps mechanisms for the formation of a carbene type of intermediate through a four‐membered cyclic transition structure can not be overlooked. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate
Authors: Ghosh Arun , Sciamanna Steven F. , Dahl Jeremy E. , Liu Shenggao , Carlson Robert M. K. , Schiraldi David A. 
Published: March 2007

AbstractNanoscale MolecularDiamond products (various diamondoid materials), obtained from petrochemical feedstocks, have been investigated as additives for polypropylene and polycarbonate. Three of the homologues of this family (diamantane, triamantane, and the [121]tetramantane isomer) have marginal effects on the thermal and mechanical properties of nonpolar/semicrystalline polypropylene. Mixtures of methylated tetramantane nanofillers also increase the stress–strain behavior of polypropylene composites without significantly impacting their glass transition temperatures. The addition of the selected diamondoids to amorphous/moderately polar polycarbonate increases the polymer tensile modulus significantly with marginal increases in the yield stress. The effects of the selected diamondoids on the thermal stability, crystallinity, and optical properties of polypropylene and polycarbonate are also reported. The results for the mechanical properties show that the selected diamondoids behave as plasticizers in polypropylene, whereas in polycarbonate, they act as antiplasticizers without adversely affecting the optical clarity. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1077–1089, 2007
Practical usage of O'Brien's OLS and GLS statistics in clinical trials
Authors: Dallow Nigel S. , Leonov Sergei L. , Roger James H. 
Published: March 2007

AbstractMultivariate techniques of O'Brien's OLS and GLS statistics are discussed in the context of their application in clinical trials. We introduce the concept of an operational effect size and illustrate its use to evaluate power. An extension describing how to handle covariates and missing data is developed in the context of Mixed models. This extension allowing adjustment for covariates is easily programmed in any statistical package including SAS. Monte Carlo simulation is used for a number of different sample sizes to compare the actual size and power of the tests based on O'Brien's OLS and GLS statistics. Copyright © 2007 John Wiley & Sons, Ltd.
A Measure of Domain of Applicability for QSAR Modelling Based on Intelligent K‐Means Clustering
Authors: Stanforth Robert W. , Kolossov Evgueni , Mirkin Boris 
Published: March 2007

AbstractThe prediction of a biological activity using a Quantitative Structure–Activity Relationship (QSAR) model is valid only if the compound in question is inside the model's domain of applicability. The existing methods for determining the domain of applicability in descriptor space suffer from problems including poor handling of nonconvex training sets and computational inefficiency. In this paper, we propose a cluster‐based approach to modelling the domain of applicability, which may overcome some of the shortcomings of the existing approaches described. We investigate applying an intelligent version of the K‐means clustering algorithm to this problem, modelling the training set as a collection of clusters in the descriptor space. A test compound is assigned ‘fuzzy membership’ of each individual cluster, from which an overall distance may be calculated. Finally, we experimentally assess how this cluster‐based approach compares with the existing methods.
Three‐Dimensional Quantitative Structure–Activity Relationship of MT3 Melatonin Binding Site Ligands: A Comparative Molecular Field Analysis
Authors: Farce Amaury , Dilly Sébastien , Sabaouni Ahmed , Yous Saïd , Berthelot Pascal , Boutin Jean A. , Delagrange Philippe , Renard Pierre , Chavatte Philippe 
Published: March 2007

AbstractThe Three‐Dimensional Quantitative Structure–Activity Relationship (3D‐QSAR) approach using Comparative Molecular Field Analysis (CoMFA) was applied to a series of 39 compounds evaluated as MT3 binding site ligands. The X‐ray crystal structure of MT3/quinone reductase 2 was used to obtain the putative bioactive conformation of these ligands. Five statistically significant models were obtained from the randomly constituted training sets (30 compounds) and subsequently validated with the corresponding test sets (nine compounds). The best predictive model (n=30, q2=0.608, N=3, r2=0.897, s=0.288, F=75.4) can predict inhibitory activity for a wide range of compounds and offers important structural insight into designing MT3 ligands prior to their synthesis.
Exploration of Physicochemical Properties and Molecular Modeling Studies of Furanylamide Analogs as Antituberculosis Agents
Authors: Gupta Revathi A. , Gupta Arun Kumar , Soni Love Kumar , Kaskhedikar S. G. 
Published: March 2007

AbstractIn the present study, an attempt has been made to explore physicochemical requirements of furanylamide analogs for binding with Mycobacterium tuberculosis UDP‐galactopyranose mutase. Sequential Multiple Linear Regression (SEQ‐MLR) technique was used for the development of a quantitative structure–activity relationship. The quality of QSAR models obtained from SEQ‐MLR is in acceptable statistical range (explained variance ranging from 77.0 to 91.3%). The statistical qualities of the SEQ‐MLR equations were judged by the parameters like explained variance (r2adj), correlation coefficient (r), Standard Error of Estimate (SEE), and variance ratio (F) at specified Degrees of Freedom (df). The generated equations were internally validated using the leave‐one‐out technique. The selected equations were further validated using a test set considering a predictive squared correlation coefficient (r2pred). The study suggested the indispensable nature of the nitro group on furanylamide scaffold and decisiveness of the van der Waals volume for the activity. The toxicity of the furanylamide analogs might be reduced by limiting the number of hydrogen acceptor groups. The selectivity of the compounds was supported by 3D‐Molecular Representation of Structure based on Electron Diffraction (3D‐MoRSE) code at 24th signal by atomic weight and the presence of nitro group. The binding of furanylamide analogs in M. tuberculosis UDP‐galactopyranose mutase enzyme was explored with the help of docking. The most stable ligand–enzyme complex of compound 2 showed that a ligand binds in the vicinity of the FAD. The nitro group buried in the positive charged pocket, which comprised of Arg‐261 and Lys‐164, depicted the crucial ionic interaction. The phenyl ring of the ligand plays a key role in the hydrophobic interaction by π–π stacking with Tyr‐366 and Tyr‐328.
Amphiphilic Conjugated Block Copolymers: Synthesis and Solvent‐Selective Photoluminescence Quenching
Authors: Tu Guoli , Li Hongbo , Forster Michael , Heiderhoff Ralf , Balk Ludwig J. , Sigel Reinhard , Scherf Ullrich 
Published: March 2007

AbstractA novel, amphiphilic, conjugated block copolymer is described, which was prepared by a Suzuki‐type cross‐coupling of 2‐bromo‐[9,9‐bis(2‐ethylhexyl)fluorene]‐7‐pinacolato boronate as an AB‐type monomer and monobromo‐substituted poly[3‐(6‐bromohexyl)thiophene] (Br‐P3BrHT) as a polymeric end capper in the key step. PF‐P3PHT (P2; PF=poly(9,9‐dialkylfluorene); P3PHT=poly[3‐(6‐diethylphosphonato‐hexyl)thiophene]) as the amphiphilic target polymer was then generated in a polymer‐analogous conversion of the alkyl bromide side chains of the PF‐P3BrHT (P1) precursor into polar alkyl phosphonate groups by reaction with triethyl phosphite. P2 shows a strong influence of the solvent polarity on the optical spectra (absorption, emission). Treatment of solutions of P2 in tetrahydrofuran (THF), a nonselective solvent, with increasing amounts of solvents that are selective for the polar polythiophene blocks (water) or the nonpolar polyfluorene blocks (hexane), respectively, results in the formation of two different types of core–shell aggregates, which show rather different optical properties (photoluminescence quenching, excitation energy transfer).
160‐m‐Fachwerkturm für eine Windenergieanlage – Die höchste Windenergieanlage der Welt
Authors: Dehm Joachim 
Published: March 2007

AbstractIn Laasow ca. 20 km westlich von Cottbus wurde die höchste Windenergieanlage der Welt aufgestellt. Sie hat eine Nabenhöhe von 160 m und mißt bis zur obere Flügelspitze bis 205 m. Der Stahlgitterturm der Fa. SeeBa trägt eine 2,5‐MW‐Maschine FL2500 der Fa. Fuhrländer (Bilder 1 und 2). Mit einem prognostizierten Ertrag von gut 7 Mio. kWh Strom im Jahr kann diese Anlage den Jahresverbrauch von 1800 Vier‐Personen‐Haushalten abdecken.Durch den Vorstoß in diese Höhen werden an die Planer, Statiker, Lieferanten und Monteure besondere Ansprüche gestellt. Hier soll ein kurzer Überblick über die besonderen Anforderungen bei der Statik dieses Turmes erfolgen. Auch die Unterschiede des für das Tragwerk gewählten Gittermastes im Vergleich zu den bisher üblichen Rohrmasten werden herausgestellt.
Neuartige Umbaukonzepte für einen 280 m hohen abgespannten Mast
Authors: Hornburg Stefan M. , Schuh Bernhard 
Published: March 2007

AbstractIm Zuge einer Optimierung des Antennensystems der Langwellen‐Sendeanlage Europe 1 waren umfangreiche Sanierungs‐ und Verstärkungsmaßnahmen an einem 280 m hohen abgespannten Sendemast erforderlich. Durch den geplanten Umbau und die damit verbundene höhere Belastung des Tragwerks mußten die Eckstiele von drei Schüssen ausgetauscht werden. Dazu wurde der Mast mit Hilfe einer hydraulischen Hebeeinrichtung und einer Gerüstkonstruktion angehoben. Die Gerüstkonstruktion wurde ohne eine direkte Schraubverbindung mit Rohrschellen gleitfest an den Mast geklemmt. Im überbrückten Bereich konnten so die betroffenen Eckstiele ausgebaut und durch stärkere Profile ersetzt werden. Zusätzlich wurde ein neues Isolationskonzept nach dem Fail‐Safe‐Prinzip realisiert. Hierzu wurde eine numerische Simulation durchgeführt, um zu zeigen, welche Auswirkung ein Isolatorbruch auf die Seilkräfte hat.
Seilunterstützte Montageverfahren im Stahl‐ und Anlagenbau
Authors: Einhaus Marco 
Published: March 2007

AbstractIn zunehmendem Maße müssen Arbeiter und Monteure aufgrund von komplizierten Gebäudegeometrien schwierigste Montagesituationen unter ständiger Absturzgefahr meistern. Sicherheit hat dabei höchste Priorität! Ob Architekt, Konstrukteur, Fassadenbauer, Anlagenbetreiber, Bauherr oder Bauleiter – wird die Arbeitsaufgabe unter Absturzgefahr zu diffizil, greift man auf seilunterstützte Arbeitsverfahren zurück.Unter seilunterstützten Arbeitsverfahren versteht man den Einsatz von Arbeitnehmern, die sich mit persönlicher Schutzausrüstung (Auffanggurt, Verbindungsmittel, Bandfalldämpfer) gegen Absturz an geeigneten Anschlagpunkten sichern bis hin zu Höhenarbeitern, die am Seil frei hängend besondere Montagen in großer Höhe ausführen. Die Höhenarbeiter können unter Anwendung von Seiltechnik an vertikalen, hohen oder stark geneigten Fassaden, Bauten und Strukturen für den Unterhalt, Kontrollarbeiten, kleine Renovierungen, Montagen und Installationen eingesetzt werden.Seilunterstützte Arbeitsverfahren müssen nach der Deutschen Betriebssicherheitsverordnung (BetriebSichV) mit zwei voneinander unabhängigen Seilen durchgeführt werden. Das heißt, man benötigt ein Zugangs‐ und ein Positionierungsseil. Somit entsteht eine redundante Sicherung, die bei sicherheitsgerechter Anwendung ein Abstürzen unmöglich macht.
Untersuchungen zur Ermüdungsfestigkeit von Paßschrauben beim Abscheren
Authors: Wichtowski Bernard 
Published: March 2007

AbstractIm Beitrag werden Ergebnisse von Ermüdungsversuchen zum Abscheren der Paßschrauben M16×1 der Klasse 5.8 nach PN‐91/M‐82342 vorgestellt. Die Untersuchungen umfaßten 15 zweischnittige Versuchskörper, die in fünf Belastungsschritten einseitig zyklisch zugbelastet wurden. Die Gleichung der Regressionsgerade wurde aufgrund der Untersuchungsergebnisse mit der Methode der kleinsten Quadrate bearbeitet. Der lineare Korrelationsfaktor wurde berechnet und der Vertrauensbereich bestimmt. Aus der Gleichung der Regressionsgerade für 2·106 Lastzyklen ergab sich eine dauerhafte Ermüdungsfestigkeit Ztj von 215 MPa.
Modelluntersuchungen zur Windeinwirkung auf stählerne Doppelmantelbehälter
Authors: Ziółko Jerzy , Perliński Aleksander 
Published: March 2007

AbstractDer Beitrag stellt Ergebnisse von Windkanalversuchen mit zylinderförmigen vertikalen Doppelmantelbehältern mit festem und schwimmendem Dach vor. Bei den Windkanalversuchen wurde die Druckverteilung auf die beiden Mäntel und die beiden Dächer gemessen. Analysiert wurden der Einfluß des Abstandes zwischen den Behältermänteln, der Art des Daches und der Lage des schwimmenden Daches auf die Druckbelastung und ihre Verteilung. Die Ergebnisse der Messungen wurden in Form von Druckkennzahl (Cp)‐Diagrammen dargestellt.
Interaktionsdiagramme zum vereinfachten Beulsicherheitsnachweis für die Stahlsorten S 275, S 420 und S 460
Authors: Misiek Thomas 
Published: March 2007

AbstractDer Beulsicherheitsnachweis für vierseitig gelagerte, unversteifte lange Platten kann nach DIN 18800‐3:1990‐11, Element (204) als vereinfachter Nachweis durch Einhaltung von grenz(b/t)‐Werten geführt werden. Für allein durch Randspannungen σx und τ beanspruchte Platten aus den Stahlsorten S 275, S 420 oder S 460 werden für diesen Nachweis Interaktionsdiagrammen aufbereitet.
A block‐on‐ring tribocorrosion setup for combined electrochemical and friction testing
Authors: Jellesen M.S. , Hansen M.Ø. , Hilbert L.R. , Møller P. 
Published: March 2007

AbstractThe combined action of corrosion and wear can cause degradation of equipment, and thereby financial losses related to the renewal or repair of damaged equipment. In the food industry, metal degradation is a major concern since metal release eventually can cause health risks for consumers. This study describes a block‐on‐ring testing facility used to determine sliding wear, and additionally allowing for electrochemical measurements, such as potentiodynamic polarization curves and potentiostatic monitoring of current and potential. To verify the reliability and reproducibility of this block‐on‐ring tribocorrosion setup, the tribological and electrochemical behaviour of stainless steel sliding against a ceramic ring in sulphuric acid has been determined. Furthermore, a case taken from the food industry has been examined. The study shows that results made on the described block‐on‐ring testing facility are reliable and can provide improved information about material properties when the material is exposed to combined chemical and mechanical degradation. Copyright © 2007 John Wiley & Sons, Ltd.
Diffusion‐weighted magnetic resonance imaging of acute hypoxic‐ischemic cerebral lesions in the survivor of a monochorionic twin pregnancy: case report
Authors: Righini A. , Kustermann A. , Parazzini C. , Fogliani R. , Ceriani F. , Triulzi F. 
Published: March 2007

AbstractMonochorionic twin pregnancies complicated by the death of one twin are associated with substantial morbidity in the survivor, with a high risk of developing hypoxic‐ischemic brain damage. In this report, we demonstrate how prenatal diffusion‐weighted magnetic resonance imaging detected focal ischemic lesions in the survivor of a monochorionic twin pregnancy within 1–2 days of cotwin death. A very early diagnosis of cerebral ischemic lesions might influence the management of the pregnancy. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Vesico‐ureteral reflux in children with prenatally detected hydronephrosis: a systematic review
Authors: van Eerde A. M. , Meutgeert M. H. , de Jong T. P. V. M. , Giltay J. C. 
Published: March 2007

AbstractObjectiveTo investigate the value of prenatally detected hydronephrosis (PNH) as a prognostic factor for vesico‐ureteral reflux (VUR).MethodsThe MEDLINE database was searched for articles on PNH and VUR published between 1980 and 2004. A total of 18 studies were identified and reviewed for various aspects. Results were separated for primary and/or secondary VUR whenever possible, because of the different underlying pathogenic mechanisms.ResultsThere was considerable variation between the different studies with respect to methodology and study design. One of the main discrepancies was the way in which postnatal abnormalities were ascertained: by postnatal ultrasound, voiding cystourethrogram (VCUG) alone, or combined or sequential ultrasound and VCUG. Taking these limitations into account, the published data showed there to be a mean prevalence of 15% for postnatal primary VUR after PNH. Of all patients with PNH, 53% had no postnatal anomalies, whereas 29% had other anomalies, such as duplex collecting systems.ConclusionsOf all infants with PNH, 15% had primary VUR proven postnatally and 53% had no other anomalies detected. We suggest a standardized protocol for future studies, to enable better comparison of follow‐up protocols. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.