bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaktionen aktiver Methylenverbindungen mit Aziden, VIII. Über α.α′‐Azo‐ß‐dicarbonylverbindungen bzw. deren Tautomere. Ein Beitrag zur aliphatischen Azokupplung
Authors: Regitz Manfred , Stadler Dieter 
Published: July 2007

AbstractDie Umsetzung trans‐fixierter ß‐Dicarbonylverbindungen mit 0.5 Mol Tosylazid/Mol liefert α.α′‐Azo‐ß‐dicarbonylverbindungen bzw. deren Tautomere (3a–c, 6, 10, 13, 18, 23a und 23b). Dabei reagieren die aus Tosylazid und den ß‐Dicarbonylverbindungen entstehenden α‐Diazo‐Derivate unmittelbar mit weiterer ß‐Dicarbonylverbindung im Sinne einer Azokupplung. Für einige, hierbei als Zwischenprodukte auftretende α‐Diazo‐ß‐diketone (2b und 2c, 9, 17 und 21a) werden verbesserte oder neue Darstellungen durch Diazogruppen‐Übertragung angegeben. Die katalytische Hydrierung der α.α′‐Azo‐ß‐dicarbonylverbindungen in Eisessig/Acetanhydrid liefert α‐Acetylamino‐ß‐dicarbonylverbindungen (4a–c, 7, 11, 15, 24a und 24b), die somit leicht zugänglich sind.
Abfangreaktionen kurzlebiger Radikale, I. Reaktionen von radikalbildenden Azocarbonsäure‐nitrilen mit Organozinn‐hydriden1,2)
Authors: Neumann Wilhelm P. , Sommer Richard , Lind Heinrich 
Published: July 2007

AbstractBeim thermischen Zerfall von Azoisobuttersäure‐ und Azocyclohexan‐carbonsäure‐dinitril erweisen sich aliphatische Organozinn‐hydride als wesentlich stärkere Radikalfänger als Thiole. Ein Teil der Azomoleküle wird radikalisch hydrostanniert, wobei über ß‐Eliminierungen schließlich Azine entstehen. Bei Phenylazo‐isobuttersäure‐nitril ist (bis 100°) nur die Hydrostannierung mit Folgereaktionen zu beobachten. — Die einzelnen Reaktionsschritte werden untersucht, auftretende Produkte identifiziert. — Neue α‐Trialkylstannylderivate des Isobuttersäure‐ bzw. Cyclohexancarbonsäure‐nitrils werden beschrieben.
Wasserstoff‐Verschiebungen, III. Thermische Isomerisierung von cis‐Hexadien‐(1.4)
Authors: Roth Wolfgang R. , König Joachim 
Published: July 2007

Abstractcis‐Hexadien‐(1.4) (3) lagert sich bei Temperaturen um 400° zu 4‐Methyl‐cyclopenten (4) um. Dieser Isomerisierung ist ein Gleichgewicht mit cis‐1‐Methyl‐2‐vinyl‐cyclopropan (5) vorgelagert, von dem aus die Bildung von intermediär auftretendem trans‐1‐Methyl‐2‐vinyl‐cyclo‐propan (8) sowie von 4 wahrscheinlich gemacht wird. Aktivierungsparameter wurden bestimmt für die Umlagerungen.5 → 3: ΔH± = 30.2 ± 0.6 kcal/Mol; ΔS± =–11 cal/Grad·Mol.8 → 3: ΔH± = 44.6 ± 0.6 kcal/Mol; ΔS± = 1 cal/Grad·Mol.8 → 4: ΔH± = 44.6 ± 0.6 kcal/Mol; ΔS± = –4 cal/Grad·Mol.
Synthese von racem. (1S:4S:9R)(1R:4R:9S)‐cis‐Decalindiol‐(1.4)
Authors: Dittmann Walter , Stürzenhofecker Franz 
Published: July 2007

AbstractRacem. (1S:4S:9R)(1R:4R:9S)‐cis‐Decalindiol‐(1.4) (3) wird durch Epoxydierung von cis‐trans‐Cyclodecadien‐(1.5) (1) zum Monoepoxid (2) und dessen Hydrolyse stereospezifisch in hoher Ausbeute dargestellt.
Fragmentierungsreaktionen an Carbonylverbindungen mit ß‐ständigen elektronegativen Substituenten, II1). ß‐Chlorketone und Sulfonsäureester von ß‐Hydroxyketonen2)
Authors: Nerdel Friedrich , Kretzschmar Ulrich 
Published: July 2007

Abstractß‐Hydroxy‐pivalophenon‐tosylat (1a) und ß‐Chlor‐pivalophenon (1b) bilden mit Alkoholat innere Vierringketale (2‐Phenyl‐2‐alkoxy‐1‐oxa‐3.3‐dimethyl‐cyclobutane, 3). Die Reaktion läuft in Konkurrenz zur alkalischen Fragmentierung ab. Die möglichen Reaktionswege der Umsetzung von ß‐substituierten Ketonen mit Basen werden diskutiert. Die Untersuchungen werden auf aliphatische Ketone ausgedehnt.
Reaktionen der N‐Isocyan‐dialkylamine
Authors: Bredereck Hellmut , Föhlisch Baldur , Walz Klaus 
Published: July 2007

AbstractN‐Isocyan‐dialkylamine setzen sich mit Stickstoffwasserstoffsäure bzw. Schwefelwasserstoff unter α‐Addition zu 1‐Dialkylamino‐tetrazolen bzw. Thioformyl‐hydrazinen um. Mit Ameisensäure bilden sie Formyl‐hydrazine, Thiophenol wird zu Diphenyl‐disulfid oxydiert.
Über [2‐Oxo‐cyclohexyl]‐ und Bis‐[2‐oxo‐cyclohexyl]‐malonester
Authors: Schultze Georg Richard , Khorgami Mohamed Hadi , Boberg Friedrich 
Published: July 2007

AbstractDie aus Bis‐[2‐oxo‐cyclohexyl]‐malonester (2) zugänglichen ungesättigten γ‐Lactone 3 und 9 werden untersucht. Vom [2‐Oxo‐cyclohexyl]‐malonester ausgehend wird auf zwei neuen Wegen 3‐Oxo‐octahydrocinnolin (17) synthetisiert.
Die Konformation als Ursache stereoselektiver Reaktionen
Authors: Weinges Klaus , Toribio Fernando , Paulus Erna 
Published: July 2007

AbstractDer stereochemische Verlauf der am C‐Atom 2 des Tetramethyl‐(+)‐catechins (1) und des Tetramethyl‐(–)‐epicatechins (2) ablaufenden Reaktionen wird beschrieben. Die Stereoselektivität der Reaktionen wird als Folge der Konformation von 1 und 2 gedeutet. — Die Konstitution des Kondensationsproduktes 15 aus dem Catechin 1 und Resorcin wird auf massenspektrometrischem Wege gesichert. Die strukturelle Identität der Antipoden 5 und 7, 15 und 16 sowie von 6 mit seinem bereits bekannten Antipoden wurde durch Vergleich ihrer IR‐Spektren bewiesen.
Über Dihydrochinoxaline und Radikale der Chinoxalinreihe
Authors: Brandt Christa , Foerster Günther V. , Kröhnke Fritz 
Published: July 2007

AbstractEine auf zwei Wegen erhältliche rote Verbindung wird durch chemische Beweise und durch das IR‐ sowie das NMR‐Spektrum als 2‐Benzoyl‐3‐phenyl‐3.4‐dihydro‐chinoxalin erkannt. — Bei der Reduktion von Chinoxalinen in saurem Medium entstehen tieffarbige, freie Radikale, die sich durch ESR‐Messungen nachweisen lassen. Sie sind auch dadurch erhältlich, daß man äquimolekulare Mengen eines Chinoxalins mit dem zugehörigen Dihydrochinoxalin in Eisessig unter Argon zusammengibt.
Neuartige Cyanine, IV1). Ein neuer Weg zum Indolizino[1.2‐c]chinolinium‐Ringsystem
Authors: Niederdellmann Georg , Kröhnke Fritz 
Published: July 2007

AbstractEine neuartige Synthese des Indolizino[1.2‐c]chinolinium‐Ringsystems bestätigt die früher1) für die Xantho‐apocyanine angenommene Konstitution.
Radioaktive Markierung von Tropan‐Alkaloiden, IV1). Synthetischer Einbau von 14C in (—)‐Scopolamin, Scopin und Scopolin
Authors: Schmidt Hanns‐Ludwig , Werner Gottfried , Kumpe Gerhard 
Published: July 2007

AbstractDie Synthese von (—)‐Scopolamin‐[N‐14CH3]·HBr·H2O (Ausbeute: 67.5%; Aktivität: 25.4 mC/mMol) aus Nor‐(—)‐scopolamin und 14CH3J wird beschrieben. Aus Scopolamin‐[N‐14CH3]·HBr·H2O wurde durch enzymatische Hydrolyse mit Kaninchen‐Serum Scopin‐[N‐14CH3], durch alkalische Hydrolyse Scopolin‐[N‐14CH3] dargestellt. Nor‐(—)‐scopolamin bildet mit CCl4 eine kristalline Molekülverbindung (4: 1).
Die Struktur des Hamamelitannins
Authors: Mayer Walter , Kunz Werner , Loebich Friedrich 
Published: July 2007

AbstractDie von O. Th. Schmidt vorgeschlagene Struktur für Hamamelitannin wird durch den Perjodat‐Abbau von Heptamethyl‐hamamelitannin und Überführung der beiden Spaltstücke in 3‐O‐Trimethyläthergalloyl‐glycerinaldehyd‐phenylosazon bewiesen.
Über Peptidsynthesen, XXXVI. 5. Mitteilung über Glukagon. Synthese C‐terminaler Glukagon‐Teilsequenzen
Authors: Schröder Eberhard 
Published: July 2007

AbstractDie C‐terminale Heptapeptidsequenz 23–29 des Glukagons wurde als freies Peptid, L‐Valyl‐L‐glutaminyl‐L‐tryptophanyl‐L‐leucyl‐L‐methionyl‐L‐asparaginyl‐L‐threonin, synthetisiert. Die Sequenz 20–22 wurde als tert.‐Butyloxycarbonyl‐L‐glutaminyl‐L‐asparaginyl‐L‐phenylalanin‐azid mit der Heptapeptidsequenz 23–29 zum tert.‐Butyloxycarbonyl‐decapeptid kondensiert. Das Decapeptid konnte ferner auf zwei verschiedenen Wegen in voll geschützter Form (C‐terminal O‐tert.‐Butyl‐L‐threonin‐tert.‐butylester) synthetisiert werden.
High glucose stimulates GRO secretion from rat microglia via ROS, PKC, and NF‐κB pathways
Authors: Quan Yi , Du Jianhai , Wang Xian 
Published: July 2007

AbstractHyperglycemia causes direct neuronal damage in diabetic encephalopathy. Microglia have been found to be activated in diabetic encephalopathy, presumably mediating and amplifying neuron degeneration. Chemokine IL‐8 plays an important role in the pathogenesis of encephalopathy. Therefore, we investigated whether high glucose could activate microglia and stimulate IL‐8 secretion and if so, the possible mechanisms that were involved. ELISA results showed that treatment with high glucose (35 mM) compared with treatment with low glucose (10 mM) time‐dependently elevated secretion of GRO (the rat ortholog of human IL‐8) in primary cultured rat microglia. Real‐time PCR results showed GRO mRNA expression also increased in response to high glucose in a time‐dependent manner. These effects were specific to high glucose because the osmolality control had no such effect. High‐glucose treatment stimulated the formation of ROS, as seen in the DCF fluorescence assay, increased phosphorylation of PKC, as seen in the Western blot analysis, and activated NF‐κB, as seen in the luciferase reporter assay. In addition, treatment with the ROS scavenger NAC (2 mM) significantly reduced the high glucose–induced phosphorylation of PKC and GRO secretion. Treatment with the PKC activator PMA (10–50 nM) stimulated GRO secretion, and the PKC inhibitors calphostin C (300 nM) or chelerythrine (1 μM) attenuated the high glucose–induced GRO secretion. Furthermore, the NF‐κB inhibitors MG132 (10 μM) or PDTC (5 μM) completely blocked the high glucose–induced GRO secretion. In conclusion, high glucose induces GRO secretion and mRNA expression in activated rat microglia, which is mediated by the ROS, PKC, and NF‐κB pathways. High glucose–induced IL‐8 production by microglia may contribute to diabetic encephalopathy. © 2007 Wiley‐Liss, Inc.
Statistical downscaling model based on canonical correlation analysis for winter extreme precipitation events in the Emilia‐Romagna region
Authors: Busuioc A. , Tomozeiu R. , Cacciamani C. 
Published: July 2007

AbstractOptimum statistical downscaling models for three winter precipitation indices in the Emilia‐Romagna region, especially related to extreme events, were investigated. For this purpose, the indices referring to the number of events exceeding the long‐term 90 percentile of rainy days, simple daily intensity and maximum number of consecutive dry days were calculated as spatial averages over homogeneous sub‐regions identified by the cluster analysis. The statistical downscaling model (SDM) based on the canonical correlation analysis (CCA) was used as downscaling procedure. The CCA was also used to understand the large‐/regional‐scale mechanisms controlling precipitation variability across the analysed area, especially with respect to extreme events. The dynamic (mean sea‐level pressure‐SLP) and thermodynamic (potential instability‐δQ and specific humidity‐SH) variables were considered as predictors (either individually or together). The large‐scale SLP can be considered a good predictor for all sub‐regions in the dry index case and for two sub‐regions in the case of the other two indices, showing the importance of dynamical forcing in these cases. Potential instability is the best predictor for the highest mountain region in the case of heavy rainfall frequency, when it can be considered as a single predictor. The combination of dynamic and thermodynamic predictors improves the SDM's skill for all sub‐regions in the dry index case and for some sub‐regions in the simple daily intensity index case.The selected SDMs are stable in time only in terms of correlation coefficient for all sub‐regions for which they are skilful and only for some sub‐regions in terms of explained variance. The reasons are linked to the changes in the atmospheric circulation patterns influencing the local rainfall variability in Emilia‐Romagna as well as the differences in temporal variability over some sub‐regions and sub‐intervals. It was concluded that the average skill over an ensemble of the most skilful and stable SDMs for each region/sub‐interval gives more consistent results. Copyright © 2007 Royal Meteorological Society
Pathway and single gene analyses of inhibited Caco‐2 differentiation by ascorbate‐stabilized quercetin suggest enhancement of cellular processes associated with development of colon cancer
Authors: Dihal Ashwin A. , Tilburgs Chantal , van Erk Marjan J. , Rietjens Ivonne M. C. M. , Woutersen Ruud A. , Stierum Rob H. 
Published: July 2007

AbstractThe aim was to investigate mechanisms contributing to quercetin's previously described effects on cell‐proliferation and ‐differentiation, which contradicted its proposed anticarcinogenic potency. In a 10‐day experiment, 40 μM quercetin stabilized by 1 mM ascorbate reduced Caco‐2 differentiation up to 50% (p < 0.001). Caco‐2 RNA from days 5 and 10, hybridized on HG‐U133A2.0 Affymetrix GeneChips®, showed 1743 affected genes on both days (p < 0.01). All 14 Caco‐2 differentiation‐associated genes showed decreased expression (p < 0.01), including intestinal alkaline phosphatase, that was confirmed technically (qRT‐PCR) and functionally (enzyme‐activity). The 1743 genes contributed to 27 pathways (p < 0.05) categorized under six gene ontology (GO) processes, including apoptosis and cell‐cycle. Genes within these GO‐processes showed fold changes that suggest increased cell‐survival and ‐proliferation. Furthermore, quercetin down‐regulated expression of genes involved in tumor‐suppression and phase II metabolism, and up‐regulated oncogenes. Gene expression changes mediated by ascorbate‐stabilized quercetin were concordant with those occurring in human colorectal carcinogenesis (∼︁80–90%), but were opposite to those previously described for Caco‐2 cells exposed to quercetin without ascorbate (∼︁75–90%). In conclusion, gene expression among Caco‐2 cells exposed to ascorbate‐stabilized quercetin showed mechanisms contrary to what is expected for a cancer‐preventive agent. Whether this unexpected in vitro effect is relevant in vivo, remains to be elucidated.
On the investigation of shell buckling due to random geometrical imperfections implemented using Karhunen–Loève expansions
Authors: Craig K. J. , Roux W. J. 
Published: July 2007

AbstractFor the accurate prediction of the collapse behaviour of thin cylindrical shells, it is accepted that geometrical and other imperfections in material properties and loading have to be accounted for in the simulation. There are different methods of incorporating imperfections, depending on the availability of accurate imperfection data. The current paper uses a spectral decomposition of geometrical uncertainty (Karhunen–Loève expansions). To specify the covariance of the required random field, two methods are used. First, available experimentally measured imperfection fields are used as input for a principal component analysis based on pattern recognition literature, thereby reducing the cost of the eigenanalysis. Second, the covariance function is specified analytically and the resulting Friedholm integral equation of the
second kind is solved using a wavelet‐Galerkin approach. Experimentally determined correlation lengths are used as input for the analytical covariance functions. The above procedure enables the generation of imperfection fields for applications where the geometry is slightly modified from the original measured geometry. For example, 100 shells are perturbed with the resulting random fields obtained from both methods, and the results in the form of temporal normal forces during buckling, as simulated using LS‐DYNA®, as well as the statistics of a Monte Carlo analysis of the 100 shells in each case are presented. Although numerically determined mean values of the limit load of the current and another numerical study differ from the experimental results due to the omission of imperfections other than geometrical, the coefficients of variation are shown to be in close agreement. Copyright © 2007 John Wiley & Sons, Ltd.
Non‐alcoholic fatty liver disease: what is it, when does it occur, and why does it matter?
Authors: Preiss D , Sattar N 
Published: July 2007

AbstractThe rising pandemic of obesity and type 2 diabetes, both manifestations of insulin resistance, has heralded a rise in associated liver injury in the form of non‐alcoholic fatty liver disease (NAFLD). It is estimated that 20–30% of the population in developed countries have NAFLD. NAFLD should be suspected in those with simple clinical signs and biochemistry consistent with insulin resistance. The importance of NAFLD is two‐fold. Firstly, a small number of individuals with NAFLD, itself a relatively benign condition, will progress to more severe stages of liver disease— namely, non‐alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Secondly, the presence of NAFLD is associated with treatable features of insulin resistance and an elevated risk for type 2 diabetes. Apart from histology, there is currently no effective method to distinguish between NASH and simple steatosis. Identification of a non‐invasive marker to achieve this is much sought after. Pilot studies of lifestyle advice, insulin sensitisers and other medications have shown evidence of improvement in liver histology and serum ALT. However, the cost:benefit ratio of any new therapies, and any potential harms, must be examined carefully before being clinically advocated. Copyright © 2007 John Wiley & Sons.
Microvascular and cardiovascular disease in South Asians: the emerging challenge
Authors: Chittari M Varma , Bush K , Bellary S , Kumar S , Barnett AH , O' Hare JP 
Published: July 2007

AbstractSouth Asians now constitute 4% of the UK population and represent a significant growing minority ethnic group with distinct health care needs. Type 2 diabetes mellitus is already endemic and growing exponentially in this ethnic group. This presents a unique challenge to the overstretched resources of the NHS but, if action is not taken now, it is likely to prove highly expensive in the medium to long term. Type 2 diabetes is never mild and the microvascular and cardiovascular complications of diabetes appear to be more aggressive in the South Asians and threaten to match the exponential rise of the disease in them. Primary prevention through lifestyle changes to reduce obesity and improve diet with the aggressive reduction through pharmacological and non‐pharmacological treatments of the reversible risk factors remains the cornerstone of a systematic strategy.In this review, we will describe the problem of microvascular and cardiovascular disease in South Asians and the known causes. Finally, we will describe the United Kingdom Asian Diabetes Study, a novel culturally centred approach using a community‐based health care team in an attempt to improve microvascular and cardiovascular risk in South Asians. Copyright © 2007 John Wiley & Sons.
High incidence of reduced plasma HDL cholesterol in diabetic patients treated with rosiglitazone and fibrate
Authors: Keidar Shlomo , Guttmann Hadassa , Stam Tamar , Fishman Ilana , Shapira Chen 
Published: July 2007

AbstractBackgroundA paradoxical plasma HDL‐Cholesterol (HDL‐C) reducing effect following combined fibrate and thiazolidinediones (TZDs) therapy was recently reported in occasional cases. As HDL‐C level is inversely related to cardiovascular disease (CVD) risk, we have studied the incidence of reduced HDL‐C level following mono‐ and combined therapy with these drugs in a large diabetic population.MethodsThis study was designed as a retrospective 5‐year study. Lipid profile records of 54 000 diabetic patients were searched for transient reduction of HDL‐C to levels lower than 17 mg/dL, which was correlated with fibrates and/or TZD treatment.ResultsTransient reduction in plasma HDL‐C to values lower than 17 mg/dL was observed in 0.02% (2/11 175) of the patients treated with fibrates alone, none of the rosiglitazone‐treated patients (0/3213) and in 1.39% (9/649) of patients treated with combination of fibrate and TZD. HDL‐C lowering effect was reversible upon stopping either fibrate or rosiglitazone and in some patients it occurred within 2 weeks. In two of the patients, the effect was dose‐dependent.ConclusionSevere reduction in plasma HDL‐C is not rare when TZD and fibrates are co‐administrated to diabetic hyperlipidemic patients. As low plasma HDL cholesterol is a risk factor for CVD, the physician should be alert to this phenomenon. Copyright © 2007 John Wiley & Sons, Ltd.
Relationship between therapeutic use and abuse of opioid analgesics in rural, suburban, and urban locations in the United States
Authors: Cicero Theodore J. , Surratt Hilary , Inciardi James A. , Munoz Alvaro 
Published: July 2007

AbstractPurposeThe goal of these studies was to determine the relationship between prescribed use of opioid analgesics and their non‐medically related use (abuse) at a regional level across the country.MethodsTo gather information about prescription drug abuse, we asked 233 drug abuse treatment specialists to provide us Quarterly reports on the number of cases of prescription opioid analgesic abusers who used opioid analgesics to get high in the past 30 days.Results and ConclusionsWe found that there was a very strong correlation between therapeutic exposure to opioid analgesics, as measured by prescriptions filled, and their abuse. There were, however, geographical loci that represented outliers in which abuse was disproportionately high relative to therapeutic use (>95th percentile), most of which were in very small urban, suburban, and rural areas. The rank order of abuse shows that buprenorphine products, extended release (ER) oxycodone and methadone are the most intensely abused prescription opioid analgesics, with hydrocodone the least abused, when the data are corrected for degree of exposure, i.e., cases/1000 persons filling a prescription. If, on the other hand, one uses the number of cases/100 000 population, hydrocodone ranked as high as ER oxycodone and all other drugs grouped together at very low levels of abuse. Since the latter conclusion ignores therapeutic exposure, we conclude that the rate of abuse of highly efficacious opioid analgesics is best expressed as cases of abuse/1000 persons filling a prescription, which yields the best possible estimate of the risk‐benefit ratio of these drugs. Copyright © 2007 John Wiley & Sons, Ltd.
New links between depression and Parkinson's disease
Authors: Mayor Sue 
Published: July 2007

AbstractA multinational study –PRODEST (Profile of Depression Symptoms in PD patients) –found that 27 per cent of patients with Parkinson's disease (PD) had symptoms of depression and that more than one‐third of these continued to suffer depression despite anti‐ depressant treatment. Sue Mayor reports from a Press Conference held at Boehringer Ingelheim Center, Ingelheim am Rhein, Germany, in February. Copyright © 2007 Wiley Interface Ltd
Isoprene polymerization via reversible addition fragmentation chain transfer polymerization
Authors: Germack David S. , Wooley Karen L. 
Published: July 2007

AbstractUntil recently, the primary living radical polymerization method available for preparing polyisoprene was nitroxide‐mediated radical polymerization, with reversible addition‐fragmentation chain transfer polymerization being applied only in a few cases within the last couple of years. We report here the preparation of polyisoprene by RAFT in the presence of the trithiocarbonate transfer agent S‐1‐dodecyl‐S′‐(r,r′‐dimethyl‐r′′‐acetic acid)trithiocarbonate and t‐butyl peroxide as the radical initiator. The kinetics of this polymerization at an optimized temperature of 125 °C and radical initiator concentration of 0.2 equiv relative to transfer agent have been studied in triplicate and demonstrate the living nature of the polymerization. These conditions resulted in polymers with narrow polydispersity indices, on the order of 1.2, with monomer conversions up to 30%. Retention of chain‐end functionality was demonstrated by polymerizing styrene as a second block from a polyisoprene macrotransfer agent, resulting in a block copolymer presenting a unimodal gel permeation chromatogram, and narrow molecular weight distribution. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4100–4108, 2007