bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of grape maturity on the foaming properties of base wines and sparkling wines (Cava)
Authors: Esteruelas Mireia , González‐Royo Elena , Kontoudakis Nikolaos , Orte Antonio , Cantos Antoni , Canals Joan Miquel , Zamora Fernando 
Published: September 2014

AbstractBACKGROUNDThe aim of this paper is to determine the main factors that influence the foaming properties of base wines and sparkling wines and, in particular, the role played by the maturity of the grapes in the controlled designation of origin (CDO) Cava. Macabeo, Xarel.lo, Parellada and Chardonnay grapes were harvested at two different maturity levels in two vintages. The first harvest was selected because of its desirable titratable acidity and the second because of its optimal sugar concentration. The mono‐varietal base wines and standard blends were transformed into sparkling wines and aged for 14 months.RESULTSThe results indicate that the main factors affecting foam properties are ethanol content, high molecular weight polysaccharides and gluconic acid (which have a negative effect), and proteins (which have a positive effect).CONCLUSIONThe main conclusion of this study is that the foaming properties of wines can be improved if harvest dates are advanced. © 2014 Society of Chemical Industry
Ultrasound to differentiate thyroglossal duct cysts and dermoid cysts in children
Authors: Oyewumi Modupe , Inarejos Emilio , Greer Mary‐Louise , Hassouneh Basil , Campisi Paolo , Forte Vito , Propst Evan J. 
Published: September 2014

Objectives/HypothesisTo determine if ultrasound could differentiate between thyroglossal duct cysts (TGDC) and midline dermoid cysts (DC).Study DesignCohort study.MethodsA search of pathology reports yielded 91 patients with TGDC or midline DC. Ultrasound images were presented to a radiologist blinded to pathology who evaluated the following: 1) depth of lesion from skin, 2) maximum diameter, 3) dimensions, 4) midline location, 5) distance from base of tongue, 6) tract, 7) wall regularity, 8) wall thickness, 9) margin definition, 10) heterogeneity, 11) internal septae, 12) solid components, 13) intralesional Doppler flow, and 14) posterior enhancement. The predictive power of these variables was evaluated in a multiple logistic regression model.ResultsThere were 53 TGDC and 38 DC. TGDC were significantly more likely than DC to have the following features: 1) smaller distance from base of tongue, 2) tract, 3) irregular wall, 4) ill‐defined margin, 5) internal septae, 6) solid components, and 7) intralesional Doppler flow. Three clinically reliable ultrasound variables were independently able to discriminate between TGDC and DC. A predictive model was fashioned whereby each variable was scored as 0 or 1, with a total score calculated (septae + irregular wall + solid components = TGDC [or SIST] score). We propose a scoring system whereby 0 = suggestive of DC; 1 = suggestive of TGDC; and ≥2 = highly suggestive of TGDC.ConclusionsIt may be possible to differentiate between TGDC and midline DC preoperatively using ultrasound.Level of EvidenceN/A. Laryngoscope, 125:998–1003, 2015
Factors influencing sleep time with oxygen saturation below 90% in sleep‐disordered breathing
Authors: Bostanci Asli , Turhan Murat , Bozkurt Selen 
Published: September 2014

Objectives/HypothesisTo determine factors influencing sleep time with oxygen saturation below 90% (ST90) in a population referred to a tertiary sleep center for assessment of possible sleep‐disordered breathing (SDB).Study DesignRetrospective review of demographic and polysomnographic data of 731 consecutive patients with suspected SDB.MethodsBivariate correlation analyses were performed, and Spearman rho coefficients were calculated. Variables with a marginal association with ST90 (P < .05) in the bivariate analysis were included into the multiple regression analysis.ResultsThe distributions of SDB were as follows: normal/simple snoring, 18.2%; mild obstructive sleep apnea (OSA), 25.6%; moderate OSA, 17.4%; and severe OSA, 38.9%. The univariate analysis revealed a significant correlation between ST90 and age (r = 0.204), body mass index (BMI) (r = 0.440), arousal index (r = 0.754), apnea‐hypopnea index (AHI) (r = 0.761), mean oxygen saturation (SaO2) (r = −0.506), and mean O2 desaturation (r = 0.858) (P < .001 for all parameters). In multiple regression analysis, age (P < .001), BMI (P = .040), male gender (P = .001), AHI (P < .001), mean SaO2 (P < .001), and mean O2 desaturation (P < .001) were found to be independent parameters influencing ST90. Furthermore, these parameters explained a significant proportion of variance in ST90 (R2 = 0.794, F (6, 729) = 464.65, P < .001). Although there was a strong correlation between AHI and ST90 (r = 0.76, P < .001), a large variation of ST90 values was observed, especially within the severe OSA group.ConclusionsThe study results provide supporting evidence that patients with similar AHI may have quite different values of ST90, and thereby hypoxia. The stratification of patients with OSA according to AHI combined with ST90 may allow better identification of prognostic information.Level of Evidence4 Laryngoscope, 125:1008–1012, 2015
Clinical cell therapy imaging using a perfluorocarbon tracer and fluorine‐19 MRI
Authors: Ahrens Eric T. , Helfer Brooke M. , O'Hanlon Charles F. , Schirda Claudiu 
Published: September 2014

PurposeCellular therapeutics are emerging as a treatment option for a host of serious human diseases. To accelerate clinical translation, noninvasive imaging of cell grafts in clinical trials can potentially be used to assess the initial delivery and behavior of cells.MethodsThe use of a perfluorocarbon (PFC) tracer agent for clinical fluorine‐19 (19F) MRI cell detection is described. This technology was used to detect immunotherapeutic dendritic cells (DCs) delivered to colorectal adenocarcinoma patients. Autologous DC vaccines were labeled with a PFC MRI agent ex vivo. Patients received DCs intradermally, and 19F spin‐density‐weighted MRI at 3 Tesla (T) was used to observe cells.ResultsSpin‐density‐weighted 19F images at the injection site displayed DCs as background‐free “hot‐spot” images. 19F images were acquired in clinically relevant scan times (<10 min). Apparent DC numbers could be quantified in two patients from the 19F hot‐spots and were observed to decrease by ∼50% at injection site by 24 h. From 3T phantom studies, the sensitivity limit for DC detection is estimated to be on the order of ∼105 cells/voxel in this study.ConclusionThese results help to establish a clinically applicable means to track a broad range of cell types used in cell therapy. Magn Reson Med 72:1696–1701, 2014. © 2014 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.
Relaxivity‐iron calibration in hepatic iron overload: Predictions of a Monte Carlo model
Authors: Ghugre Nilesh R. , Doyle Eamon K. , Storey Pippa , Wood John C. 
Published: September 2014

PurposeR2* (1/T2*) and single echo R2 (1/T2) have been calibrated to liver iron concentration (LIC) in patients with thalassemia and transfusion‐dependent sickle cell disease at 1.5T. The R2*‐LIC relationship is linear, whereas that of R2 is curvilinear. However, the increasing popularity of high‐field scanners requires generalizing these relationships to higher field strengths. In this study, we tested the hypothesis that numerical simulation can accurately determine the field dependence of iron‐mediated transverse relaxation rates.MethodsWe previously replicated the calibration curves between R2 and R2* and iron at 1.5T using Monte Carlo models incorporating realistic liver structure, iron deposit susceptibility, and proton mobility. In this paper, we extend our model to predict relaxivity‐iron calibrations at higher field strengths. Predictions were validated by measuring R2 and R2* at 1.5T and 3T in six β‐thalassemia major patients.ResultsPredicted R2* increased twofold at 3T from 1.5T, whereas R2 increased by a factor of 1.47. Patient data exhibited a coefficient of variation of 3.6% and 7.2%, respectively, to the best‐fit simulated data. Simulations over the range 0.25T–7T showed R2* increasing linearly with field strength, whereas R2 exhibited a concave‐downward relationship.ConclusionA model‐based approach predicts alterations in relaxivity‐iron calibrations with field strength without repeating imaging studies. The model may generalize to alternative pulse sequences and tissue iron distribution. Magn Reson Med 74:879–883, 2015. © 2014 Wiley Periodicals, Inc.
Z‐score reference ranges for normal fetal heart sizes throughout pregnancy derived from fetal echocardiography
Authors: Li Xinyan , Zhou Qichang , Huang Huan , Tian Xiaoxian , Peng Qinghai 
Published: September 2014

AbstractObjectiveTo construct Z‐score reference ranges for normal fetal heart sizes throughout pregnancy.MethodsThis is a prospective cross‐sectional investigation of 809 normal singleton fetuses from 11th week to term. Fetal transverse heart diameter (HD), heart length (HL), heart circumference (HC) and heart area (HA) were derived from two‐dimensional echocardiography. The regression analyses of the mean (M) and the standard deviation (SD) for each parameter were calculated separately, using fetal somatic sizes as independent variables. A group of fetal heart diseases was assessed using these parameters.ResultsStrong correlations were found between fetal heart sizes and somatic sizes. Linear‐cubic regression equations were each fitted to the models of the means of the heart sizes, whereas linear‐quadratic equations were fitted to the models of the SDs. HD was the dependent variable that provided the highest correlation coefficient with all of the fetal sizes, followed by HL, HC and HA. All fetuses with Ebstein's anomaly and most with homozygous α‐thalassemia‐1 demonstrated Z‐scores reflective of increased heart sizes.ConclusionThe calculation of Z‐scores for heart sizes as a function of fetal somatic size is simple and may be useful for quantitative assessment of some cardiac diseases, particularly cardiomegaly caused by homozygous α‐thalassemia‐1. © 2014 John Wiley & Sons, Ltd.
Inclusion compounds of linear polymers and polymerization of monomers included in perhydrotriphenylene
Authors: Farina M. , Natta G. , Allegua G. , Löffelholz M. 
Published: September 2014

AbstractThe trans‐anti‐trans‐anti‐trans isomer of perhydrotriphenylene C18H30 forms crystalline inclusion compounds with linear macromolecules, such as polyethylene, 1,4‐polybutadiene, and poly(oxyethylene glycol). The main results concerning the constitution, determined by x‐ray diffraction and by differential thermal analysis, as well as the stability of these compounds, are reported here. Moreover, studies were made on the polymerization of various monomers included in PHTP by γ‐rays radiation. In several cases, an inclusion compound of the polymer in PHTP is obtained from such a reaction. A high degree of stereoregularity has been observed for some of the polymers obtained (e.g., polydiolefins); the first reported example of an isotactic polymer obtained by γ‐rays polymerization is due to the above method; it is the isotactic trans‐poly‐1,4‐pentadiene.
Stereospecific polymerization of butadiene by catalysts prepared from π‐allyl nickel halides
Authors: Porri L. , Natta G. , Gallazzi M. C. 
Published: September 2014

AbstractButadiene has been polymerized by π‐allyl‐Ni‐halides (I) to low molecular weight stereoregular polymers, with either benzene, n‐pentane, tetrahydrofuran, cyclohexanol, or ethyl alcohol used as solvents. Solid polymers and oily products were simultaneously obtained as polymerization products. In benzene as solvent, π‐allyl‐Ni‐I and π‐allyl‐Ni‐Br gave predominantly trans‐1,4 polymers, while π‐allyl‐Ni‐Cl gave polymers largely composed of cis‐1,4 units. In the other solvents predominantly trans‐1,4 polymers were obtained, irrespective of the nickel derivative used. By reacting π‐allyl‐Ni‐Br, in benzene solution, with either AlBr3, Al2(O‐i‐C3H7)3Br3, BF3 or TiCl2 (O‐i‐C3H7)2, complexes were obtained (II) which polymerize butadiene to predominantly cis‐1,4 polymers. Evidence is reported that these complexes are of ionic type and contain the cationmagnified imageThe different stereospecificity observed in the polymerizations by I and II is interpreted on the basis of the different mode of coordination of butadiene to Ni of the complexes I and II, respectively.
Crystal structure of trans‐polypentenamer
Authors: Natta G. , Bassi I. W. 
Published: September 2014

Abstracttrans‐Polypentenamer, like natural rubber, crystallizes under stretching at room temperature. The x‐ray fiber spectra of crystalline trans‐polypentenamer can be interpreted on the basis of an orthorhombic unit cell whose identity periods in A. units are: a = 7.28 ± 0.10; b = 4.97 ± 0.05; c = 11.90 ± 0.10 (chain axis); Z = 4(C5H8); dcalo = 1.049 g./cm.3. Probable space groups C92v(Pna21) or D162h (Pnam). Atomic positions were deduced by trial and error. The (CHCHCH2CH2CH2) monomeric units repeat along a twofold helix. The molecular packing in the crystal state is essentially regulated by the H atoms of the CH2 groups. The packing of the trans‐polypentenamer molecules is very similar to the packing found for orthorhombic polyethylene.
A new method of synthesis of polyhydroxyphenylenes from polyatomic phenols
Authors: Paushkin Ya. M. , Polak L. S. , Omarov O. Yu. , Patalakh I. I. 
Published: September 2014

AbstractThe authors have worked out a method of synthesis of new polymeric polyatomic phenols consisting of elimination of water from diatomic phenols. The reaction was carried out by heating the parent phenols in an autoclave at temperatures from 200 to 350°C. under pressure, in the presence of zinc chloride. The yields varied from 30 to 87%, depending on the reaction conditions. The obtained polymers were soluble or insoluble high melting powders, the molecular weights of soluble fractions ranging from 350 to 2000. Hydroxybenzine was assumed to form as an intermediate product, with consequent polymerization to polyhydroxyphenylenes. With phenol as a starting monomer, the reaction leads to the formation of polyphenylenes. The elementary composition, hydroxylic values, infrared spectra, and electrophysical properties of prepared polymers have been characterized. The number of uncoupled electrons was 1018 sp./g.; the electric conductivity values for typical samples varied from 10−8–10−9 ohm−1 cm.−1; activation energy, 0.12–0.42 e.v. The temperature dependence of conductivity obeys the exponential low.
Untersuchungen zum Einstellvorgang bei osmotischen Messungen
Authors: Philipp B. , Wulf K. , Kapelle R. 
Published: September 2014

AbstractDie Arbeit befasst sich mit der raschen osmotischen Molekulargewichtsbestimumng von Polyacrylnitril und Cellulosenitrat unter Verwendung cines Zweikammer‐Osmometers, dessen Lösungsmittelzelle mittels eines flexiblen Schlauches mit einem Niveaugefäss verbunden ist. Durch Änderung der Steighöhe des Lösungsmittels unter Konstanthalten der Steighöhe der Lösung, einem im Prinzip seit längerem bekannten, aber bisher kaum konsequent betriebenen Messverfahren, wird die Gleichgewichtsdruckdifferenz sehr schnell angenähert. Der Lösungsmeniskus stellt eine Art “Nullinstrument” dar, wobei es zur Erreichung höherer Genauigkeit aber auch möglich ist, den Gleichgewichtswert von oben und unten einzugabeln. Die kurzen Messzeiten verringern gleichzeitg eine das Ergebnis verfälschende Kurzkettenpermeation in die Lösungsmittelzelle recht wesentlich, was besonders für unfraktionierte technische Produkte von Bedeutung ist.
Properties of polymer solutions
Authors: Rossi C. , Bianchi E. , Pedemonte E. 
Published: September 2014

AbstractAccording to the present theories, the Flory‐Mandelkern invariant F should assume values between 1.65 and 1.75 × 10−9 for medium and high molecular weights, and increase up to about 3 × 10−9 for very low molecular weights. By using experimental data on [η], M, and D deduced from the literature, we get a set of scattered F values, ranging from 1.40 to 1.60 and independent of molecular weight. Measurements carried out in our laboratory on polystyrene in benzene and on polyisobutylene and cyclohexane give F values independent of molecular weight in the range 103–105. The dependence of the F values upon the solvent, as observed in our experiments, is explained as due to differences in the effects of the solvent on the viscosity as compared to the diffusion.
Static dielectric properties of dilute solutions containing macromolecules with polar flexible side chains
Authors: Mandel M. 
Published: September 2014

AbstractThe static dielectric properties of polymers in nonpolar solvents are described in terms of homogeneous suspensions of spherical regions each containing a solvated macromolecule. Two models are used. The first one applies to polymers having polar side groups rigidly attached to the main chain or making a constant average direction with respect to the segment to which they are connected. This model yields a conventional relation between the dielectric increment Δ∈, and the mean‐square dipole moment (MSM) of the polymer, so that the molecular weight (M) dependency of MSM and Δ∈ are related. Another model is used for loosely coiled polymers with principal dipoles situated in flexible side groups. From a semimacroscopic calculation, using the assumption that the mean contribution of a given monomeric unit only depends on its average distance to the center of gravity, another expression is derived for Δ∈. For such systems Δ∈ could depend on molecular weight but no direct relation is expected between Δ∈ and MSM or the mean‐square end‐to‐end distance. As a first approximation, Δ∈ is independent of M, as is also found experimentally for poly(methacrylic esters) and poly(vinyl acetate) in various nonpolar solvents. It is shown that the latter model is related to a previously proposed interpretation of the dielectric dispersion for solutions of the same polymers.
Zur Kinetik der Emulsionspolymerisation von Vinylchlorid
Authors: Gerrens H. , Fink W. , Köhnlein E. 
Published: September 2014

AbstractEs wird eine Dilatometer‐Apparatur aus V2A‐Stahl beschrieben, die mit einem beweglichen Faltenbalg arbeitet und zur Messung von Emulsionspolymerisationen unter Druck geeignet ist. Nach Versuchen mit K2S2O8 als Initiator und C16H33CHOHCH2SO3Na als Emulgator nimmt bei steigender Emulgatorkonzentration [I] die Bruttorekationsgeschwindigkeit vBr proportional [I]0,8 zu, während die Teilchenzahl N konstant bleibt. Bei steigender Temperatur bleibt N konstant und vBr nimmt entsprechend einer Bruttoaktivierungsenergie von 24,2 kcal/mol zu. Bei kleinen Emulgatorkonzentrationen [S] steigt N proportional [S]1,2 und vBr ändert sich nicht. Diese Ergebnisse lassen sich mit der Smith‐Ewart Kinetik erklären, wenn man eine Abbruchsreaktion von 1. Ordnung in Bezug auf aktive Radikale annimmt und berücksichtigt, dass in diesem Falle die Volumenwachstumsgeschwindigkeit eines Latexteilchens nicht konstant ist, sondern mit [I] zunimmt. Abbruch durch Monomeres lässt sich mit den Versuchsergebnissen nicht vereinbaren. Abbruch durch Einschluss von Radikalen und Abbruch durch desaktivierende Kettenübertragung auf das Polymere in Nachbarschaft zu einer durch HCl‐Abspaltung gebildeten Doppelbindung werden diskutiert. Bei hohen Emulgatorkonzentrationen nehmen vBr und N beide proportional [S]0,6 zu. Diese Abhängigkeit lässt sich mit Smith‐Ewart Kinetik und monomolekularem Abbruch nicht erklären.
Polymerisation de l'Isoprene en Presence de Strontium
Authors: Kistler Jean‐Paul 
Published: September 2014

AbstractThe reaction was examined as a function of the nature and origin of the finely divided metal, prepared either by regeneration from its NH3 complex or by mechanical pulverization in an inert atmosphere. Isoprene (99%) was distilled over Na and prepolymerized on Li to give 99.8% purity (determined by gas chromatography). The reactions were performed in the absence of O2 at 21°C. for 65 hr. with a Sr concentration of 2%. The structure of polymers was determined by NMR. It is independent of the temperature of formation and decomposition of the Sr–NH3 complex and of the by‐products formed by decomposition of the complex.
On the phenomenological description of the nonlinear deformation behavior of rubberlike high polymers
Authors: Becker G. W. 
Published: September 2014

AbstractThe theoretical relationships for the description of the nonlinear deformation behavior of solids can be controlled rather easily by measurements on rubberlike polymers, because of the very small time dependence of their mechanical properties, and because of their large strain range. The data of recent investigations of the biaxial stress–strain behavior of a natural rubber are used for the evaluation of the gradients of the strain energy function given by Rivlin. It is demonstrated that even for a material for which the assumption of incompressibility is practically valid, the actual mechanical behavior is described much too complicated especially in the region of smaller deformations.
Diastereoisomeric compounds as possible models for stereospecific polymerization
Authors: Corradini P. , Paiaro G. , Panunzi A. 
Published: September 2014

AbstractThe stereoregular polymers of monoolefins arise from the polymerization of vinyl compounds, which do not have a symmetry plane perpendicular to the plane of the double bond. The generation of diastereoisomeric complexes when an olefin is coordinated to an asymmetric center is the first step of a polymerization process, leading to stereoregular polymers. When olefinic compounds with a symmetry lower than 2mm are coordinated to a transition metal in simple complexes, enantiomeric mixtures are obtained. The resolution of such a type of asymmetry was achieved via fractional crystallization of diastereoisomeric mixtures with an asymmetric ligand. The study of properties of cis and trans π‐complexes of the type [olefin‐Pt‐dichloro‐α‐phenethylamine] gave evidence that the formation of the cis complexes involves a remarkable asymmetric induction also in solution. Complexes of Fe(CO)4 with unsaturated carboxylic acids were also resolved.
Elektronenmikroskopische Untersuchungen an hochpolymeren Lösungen
Authors: Ruscher Ch. 
Published: September 2014

AbstractMit Hilfe der Methode der Gefriertrocknung erhält man Präparate, die den Zustand von Hochpolymeren in Lösung zu untersuchen gestattet. Für Cellulosenitrat in Butylacetat und für Polycarbonat in Methylenchlorid wird der Lösungszustand nach verschiedenen Lösezeiten demonstriert. Lösungen mit molekular gelösten Stoffen konnten ebenfalls gefunden werden. Aus solchen Aufnahmen konnte für Polycarbonate, für Polystyrol und für Polyacrylnitril jeweils ein Molekulargewicht bestimmt werden, das hinreichend genau mit den anderweitig bestimmten Werten übereinstimmt.