bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Study of the Phenolics and Saponins from Helleborus niger L. Leaves and Stems by Liquid Chromatography/Tandem Mass Spectrometry
Authors: Duckstein Sarina M. , Stintzing Florian C. 
Published: February 2014

AbstractThe aerial parts of the medicinal plant Helleborus niger L. comprise a substantial number of constituents with only few of them identified so far. To expand the knowledge of its secondary metabolite profile, extracts from H. niger leaves and stems were investigated by liquid chromatography/tandem mass spectrometry (LC/MSn). Specific identification strategies using LC/MS are established and discussed in detail. The leaves turned out to contain acylated and non‐acylated quercetin and kaempferol oligoglycosides, protoanemonin and its precursor ranunculin, β‐ecdysone, and a variety of steroidal saponins, mainly in the furostanol form. The sapogenins were elucidated as of sarsasapogenyl, diosgenyl, and macranthogenyl structures, and confirmed by comparison with the respective reference compounds. The secondary metabolite profiles were almost identical in both plant parts except that the stems lacked kaempferol derivatives and some saponins. The ranunculin derivatives and β‐ecdysone were found in both plant parts. Correlations between the location of the compound groups and the plant's defense strategies are proposed. Additionally, the role of the detected secondary metabolites as protective substances against exogenic stress and as a defense against herbivores is discussed.
Fishing for Accessory Binding Sites at GPCRs with ‘Loop‐Hooks’ – An Approach towards Selectivity? Part I
Authors: Tröger Thomas , Langenberg Maximilian , Zhong Sicheng , Ambrosini Dario , Enzensperger Christoph 
Published: February 2014

AbstractReceptor‐subtype selectivity is an important issue in medicinal chemistry and can become very difficult to achieve if the actual binding pockets of the respective receptors are highly conserved. For such cases, known unselective ligands could be equipped with a spacer that sticks outside the actual orthosteric binding pocket towards the extracellular loops. The end of the spacer bears certain functional groups to enable specific or unspecific interactions with the receptor residues outside the binding cavity. Our experiments indicated that it is possible to achieve selectivity within the dopamine D1 family with such ‘loop‐hooks’.
Interatrial pressure gradients during simulated obstructive sleep apnea: A catheter‐based study
Authors: Konecny Tomas , Khanna Amber D. , Novak Jan , Jama Abdi A. , Zawadowski George M. , Orban Marek , Pressman Gregg , Bukartyk Jan , Kara Tomas , Cetta Frank , Borlaug Barry A. , Somers Virend K. , Reeder Guy S. 
Published: February 2014

ObjectivesWe set to measure the interatrial pressure gradient during simulated obstructive sleep apnea (OSA).BackgroundOSA occurs when a sleeping patient attempts to inhale against an obstructed airway. How this event affects the interatrial pressure gradient has not been defined. We hypothesized that simulated OSA in a conscious subject (Mueller maneuver [MM], inspiration against obstruction) would promote increased right‐to‐left pressure gradient, and then the substrate for right‐to‐left atrial shunting.MethodsSelected patients underwent simultaneous measurement of airway and atrial pressures (both left and right atrium [LA, RA]) using high‐fidelity micromanometry at rest, during MM, and during VM, during right heart catheterization.ResultsTen patients (age 55 ± 11 years, two women) were successfully studied. During the onset of MM, RA pressure transiently but consistently exceeded LA pressure in response to the steep decline in intrathoracic pressure (maximum RA‐LA pressure gradient increased from 0.1 ± 1.4 mm Hg at baseline to 7.0 ± 4.3 mm Hg during MM, P < 0.001). The maximum right‐to‐left atrial pressure gradient during Mueller maneuver was higher than that achieved during the Valsalva maneuver release (P < 0.007).ConclusionsThe onset of MM increased right‐to‐left pressure gradient across the atrial septum, likely as a result of greater blood return to the RA from extrathoracic veins. The RA‐LA pressure gradient achieved during MM was greater than that observed during VM. These findings delineate the hemodynamic substrate for right to left shunting during OSA. © 2014 Wiley Periodicals, Inc.
Effect of texture on color variation in inkjet‐printed woven textiles
Authors: Bae Ji Hyun , Hong Kyung Hwa , Lamar Traci May 
Published: February 2014

AbstractInkjet‐printed textiles are influenced by a wide range of parameters due to highly diverse textile structures and the resulting textures. The goal of this study is to understand the effect of texture on color appearance in inkjet‐printed woven textiles. Cotton‐woven samples were constructed with nine different weave structures. Each sample was digitally printed with identical squares of primary colors cyan, magenta, and yellow and secondary colors red, green, and blue. The amount of ink applied was controlled consistently with an image editing software. CIE L* values were calculated from the measured reflectance. 25 observers ranked the perceived texture and color lightness of each sample. Perceived visual texture and perceived color lightness scales were estimated from the rankings using the rank order method. The measured CIE L* values and the scale of perceived lightness were positively related for the primary and secondary colors. Instrumental measurements of the textile surface characteristics were positively related to the visual scale. Texture was demonstrated to cause a measurable effect on color results in inkjet printing, both using instrumental and perceptual measures. To investigate if the color differences were substantial enough to cause “out of tolerance” ratings in textiles based on common textile industry color acceptance procedures, color differences among the samples were calculated and compared to a reference sample. Results demonstrated that color variation due to texture was sufficient to lead to rejection of a printed color in comparison to a color specification. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 297–303, 2015
Genetic and environmental influences on testosterone in adolescents: Evidence for sex differences
Authors: Harden K. Paige , Kretsch Natalie , Tackett Jennifer L. , Tucker‐Drob Elliot M. 
Published: February 2014

ABSTRACTThe current study investigated genetic and environmental influences on salivary testosterone during adolescence, using data from 49 pairs of monozygotic twins and 68 pairs of dizygotic twins, ages 14–19 years (M = 16.0 years). Analyses tested for sex differences in genetic and environmental influences on testosterone and its relation to pubertal development. Among adolescent males, individual differences in testosterone were heritable (55%) and significantly associated with self‐reported pubertal status (controlling for age) via common genetic influences. In contrast, there was minimal heritable variation in testosterone for females, and testosterone in females was not significantly associated with pubertal status after controlling for age. Rather, environmental influences shared by twins raised together accounted for nearly all of the familial similarity in female testosterone. This study adds to a small but growing body of research that investigates genetic influences on individual differences in behaviorally relevant hormones. © 2014 Wiley Periodicals, Inc. Dev Psychobiol 56: 1278–1289, 2014.
Habitat type and ambient temperature contribute to bill morphology
Authors: Luther David , Greenberg Russell 
Published: February 2014

AbstractAvian bills are iconic structures for the study of ecology and evolution, with hypotheses about the morphological structure of bills dating back to Darwin. Several ecological and physiological hypotheses have been developed to explain the evolution of the morphology of bill shape. Here, we test some of these hypotheses such as the role of habitat, ambient temperature, body size, intraspecific competition, and ecological release on the evolution of bill morphology. Bill morphology and tarsus length were measured from museum specimens of yellow warblers, and grouped by habitat type, sex, and subspecies. We calculated the mean maximum daily temperature for the month of July, the hottest month for breeding specimens at each collecting location. Analysis of covariance models predicted total bill surface area as a function of sex, habitat type, body size, and temperature, and model selection techniques were used to select the best model. Habitat, mangrove forests compared with inland habitats, and climate had the largest effects on bill size. Coastal wetland habitats and island populations of yellow warblers had similar bill morphology, both of which are larger than mainland inland populations. Temperate but not tropical subspecies exhibited sexual dimorphism in bill morphology. Overall, this study provides evidence that multiple environmental factors, such as temperature and habitat, contribute to the evolution of bill morphology.
Identifying conservation priorities for aquatic refugia in an arid zone, ephemeral catchment: a hydrological approach
Authors: Costelloe Justin F. , Russell Kathryn L. 
Published: February 2014

ABSTRACTThe conservation priorities for protecting aquatic habitat of arid zone rivers requires an understanding of the drivers of distribution, characteristics and persistence of aquatic refugia in ephemeral to intermittent arid zone rivers. We describe and analyse the aquatic refugia that persist during drought periods in a large, arid, ephemeral river, the Neales River of central Australia, concentrating on refugia for fish and the hydrological processes that influence their location, characteristics and persistence. Field data were collected on flow events, water‐level fluctuations in waterbodies during periods of no flow, waterbody dimensions and salinity. Modelling of open‐water evaporation rates, analysis of salinity changes and frequency of flow events were used to investigate the main processes determining the persistence of waterbodies. The catchment contained both fluvial waterholes and artesian springs providing aquatic refugia. In addition, anthropogenic refugia, in the form of small dams situated on the floodplain and uncontrolled flow from artesian bores, also provided potential refuge. The catchment only contained one waterhole that had a cease‐to‐flow depth sufficient to persist over a no‐flow period of 24 months, but this would also dry within 24–30 months. The capacity of the artesian springs to act as refugia is limited by their shallow depths and limited connectivity with the main river system. These data illustrate the vulnerability of the fluvial ecology of ephemeral, arid zone rivers to long‐term droughts and water resource use and assist in identifying specific refugia that require conservation management. Copyright © 2014 John Wiley & Sons, Ltd.
[(1,3‐Bis{2,6‐bis(diphenylmethyl)‐4‐methylphenyl}imidazole‐2‐ylidene)PdCl2(NEt3)]: “Throwing Away” a Different Ancillary Ligand to Enhance the Catalytic Activity at Room Temperature
Authors: Guest Daniel , Chen Ming‐Tsz , Tizzard Graham J. , Coles Simon J. , Turner Michael Lewis , Navarro Oscar 
Published: February 2014

AbstractA considerable effort in ligand design for catalysis in recent years has led to remarkable achievements in cross‐coupling reactions. In this work, we show that a careful selection of the ancillary ligands that complete the catalyst/precatalyst can provide an extra level of performance. Low loadings of [(IPr*)PdCl2(TEA)] {IPr* = 1,3‐bis[2,6‐bis(diphenylmethyl)‐4‐methylphenyl]imidazole‐2‐ylidene, TEA = triethylamine} catalyze the Buchwald–Hartwig amination reactions of aryl chlorides at room temperature in excellent yields, without the need for an inert atmosphere to set up or perform the reactions.
Copper‐Catalyzed Domino Homologation and Cycloisomerization Reactions for 3‐Pyrroline Synthesis
Authors: Shin Ye Ho , Maheswara Muchchintala , Hwang Joon Young , Kang Eun Joo 
Published: February 2014

AbstractCopper bromide was found to be an efficient catalyst for a domino reaction sequence leading to 3‐pyrrolines. The Cu(I)‐catalyzed Crabbé reaction of propargyl sulfonamide and selective cycloisomerization of the allene intermediate were carried out using microwave irradiation conditions affording a wide range of 2‐substituted‐ and 2,5‐disubstituted‐3‐pyrrolines. Mechanistic studies of the reaction intermediates revealed two possible reaction pathways; both invoke the importance of vinyl copper intermediates.
Three‐Component Synthesis of α‐Amino‐α‐aryl Carbonitriles from Arynes, Aroyl Cyanides, and N,N‐Dimethylformamide
Authors: Zhou Chao , Wang Jing , Jin Jisong , Lu Ping , Wang Yanguang 
Published: February 2014

AbstractA general and efficient synthesis of α‐amino‐α‐aryl carbonitriles through the three‐component reaction of arynes, aroyl cyanides, and DMF in a single step is described. DMF was not only used as the solvent, but it also participated in the reaction as a component. Used as the cyanide sources, the aroyl cyanides solved the toxicity and solubility problems associated with the use of HCN or metal cyanides in the Strecker synthesis. This procedure furnished α‐amino‐α‐aryl carbonitriles in moderate to good yields with broad substrate scope. Moreover, this reaction could be performed under mild conditions with high atom economy.
Impact of Compression on Effective Thermal Conductivity and Diffusion Coefficient of Woven Gas Diffusion Layers in Polymer Electrolyte Fuel Cells
Authors: Zhang X.‐M. , Zhang X.‐X. 
Published: February 2014

AbstractThe contrasting effect of compression on the ability of gas diffusion layer (GDL) in polymer electrolyte membrane fuel cell to conduct fluid, heat and electron implies that there is an optimal clamping force for cell performance. For a given GDL, understanding its associated optimal compression needs to know how its conductive ability changes with compressive pressure. In this paper we investigated the impact of compression on the effective diffusion coefficient and thermal conductivity of a carbon‐cloth GDL. The interior microstructures of the GDL under different compressions were acquired using X‐ray tomography; microscopic models were then developed to simulate gas diffusion and heat transfer in the microstructures in both in‐plane and through‐plane directions. The effective diffusion coefficient and thermal conductivity were calculated by volumetrically averaging the simulated gas diffusive and thermal flux rates at micron scale. The results show that both effective diffusion coefficient and thermal conductivity were anisotropic and their values in the in‐plane direction were higher than in the through‐plane direction. With porosity decreasing under the compression, the effective diffusion coefficient decreased faster in the through‐plane direction than in the in‐plane direction; the formula derived by Nam and Kaviany was capable of describing the change of the effective diffusion coefficient with porosity in the in‐plane direction but not in the through‐plane direction. For heat transfer, as the porosity decreased, the thermal conductivity increased faster in the through‐plane direction than in the in‐plane direction, and the increase in both directions could fit to the formula of Das et al.
Reinforcement of Highly Proton Conducting Multi‐Block Copolymers by Online Crosslinking
Authors: Titvinidze G. , Wohlfarth A. , Kreuer K.‐D. , Schuster M. , Meyer W. H. 
Published: February 2014

AbstractMulti‐block copolymers with sulfonated polysulfones as hydrophilic blocks and polyethersulfones as hydrophobic blocks have been modified by two methods: covalent and ionic crosslinking. Both methods can easily be integrated into a membrane casting process and improve the membrane properties considerably: water uptake or swelling is decreased and the mechanical stability of the membranes is strongly increased, not only in terms of higher moduli but especially with respect to much higher fracture toughness. The phase‐separated morphology is not severely affected by crosslinking so that the advantageous properties of such membranes are retained. Covalent crosslinking is preferred since it does not sacrifice proton conductivity at all.
Real time process controlling for EPB shields / Echtzeit‐Prozesscontrolling bei Erddruckschilden
Authors: Maidl Ulrich , Stascheit Janosch 
Published: February 2014

AbstractThe contribution gives an overview of the state‐of‐the‐art of process controlling in mechanised tunnelling. A web‐based and ubiquitous integrated database forms the backbone of PROCON II, a software for the analysis of machine data, project specifications, shift reports and geodetic information stored in a temporally and spatially correlated data structure. The software helps to build a knowledge base that is fed by experience from the present as well as all previous projects and that helps optimising safety, efficiency and performance of a mechanised tunnelling project. Along with a brief summary of the program features of PROCON II, this contribution gives three examples of how the software can be employed to gain insight into the key mechanisms of Earth Pressure Balanced (EPB) shield tunnelling and how it can help to improve the tunnelling performance.Der Beitrag gibt einen Überblick über den Stand der Technik des Prozesscontrolling im maschinellen Tunnelbau. Eine webbasierte und überall verfügbare integrierte Datenbank bildet das Rückgrat von PROCON II, einer Software, welche die Analyse von Maschinendaten mit Projektspezifikationen, Schichtprotokollen und geodätischen Informationen in einer räumlich und zeitlich korrelierten Datenstruktur verknüpft. Die Software unterstützt dabei den Aufbau einer Wissensbasis, die auf Erfahrungen aus dem laufenden sowie aus vorangegangenen Projekten beruht, und dabei hilft, die Sicherheit, Effizienz und Leistungsfähigkeit eines maschinellen Tunnelvortriebs zu optimieren. Neben einer kurzen Übersicht über die Programmfeatures von PROCON II beinhaltet dieser Beitrag drei Beispiele, wie die Software eingesetzt werden kann, um am Beispiel eines Erddruckschildvortriebs Einblicke in Schlüsselmechanismen zu erhalten, und wie sie dadurch helfen kann, die Vortriebsleistung zu verbessern.
Synthesis of a New Library of Pyrano‐phenazine Derivatives via a Novel Three‐Component Protocol
Authors: Shaabani Ahmad , Ghadari Rahim , Arabieh Masoud 
Published: February 2014

AbstractThe pyrano‐phenazine derivatives 6 were synthesized by an efficient procedure using the reaction between benzo[a]phenacin‐5‐ols with the condensation product of an aldehyde with Meldrum's acid in the presence of a catalytic amount of Et3N at ambient temperature. The procedure is very simple, and products could be separated from the reaction media by simple filtration. High functional‐group tolerance both in the benzo[a]phenazin‐5‐ol and aldehyde moieties, facile reaction procedure, medium‐to‐high yields, and simple separation of the products from the reaction media are the advantages of this route.
Two New Phenolic Compounds from Artemisia iwayomogi
Authors: Yan Xi‐Tao , Ding Yan , Li Wei , Sun Ya‐Nan , Yang Seo‐Young , Koh Young‐Sang , Kim Young‐Ho 
Published: February 2014

AbstractTwo new phenolic compounds, (Z)‐5′‐hydroxyjasmone 5′‐O‐{6″‐O‐[(E)‐caffeoyl]‐β‐D‐glucopyranoside} (1) and quercetin‐7‐O‐β‐D‐glucuronide methyl ester (2), along with ten known phenolic compounds, 3–12, were isolated from the aerial parts of Artemisia iwayomogi. Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR, and HR‐ESI‐TOF‐MS techniques. The inhibitory effects of compounds 1–12 on the LPS‐stimulated production of IL‐12 p40, IL‐6, and TNF‐α in bone marrow‐derived dendritic cells were evaluated.
First Synthesis of Azachlorins and Azacorrins with a N‐Atom in β‐Pyrrolic Positions
Authors: Vu Nghiem Hai , Damke Jan‐Erik , Borrmann Tobias , Latos‐Grażyński Lechosław , Montforts Franz‐Peter 
Published: February 2014

AbstractAzachlorins 7 and 11, and azahexadehydrocorrin rac‐10 are novel structural types of tetrapyrrolic macrocycles. Synthesis of the target structures bearing N‐atoms in the β‐periphery of the macrotetracycles could be achieved by attaching an imidazole moiety 4 to the tricyclic Ni complex rac‐5, followed by cyclization. Depending on the central metal ion of the bilin intermediates rac‐6a and rac‐6b, chlorin‐ or corrin‐type structures were formed by cyclization.
RNA Cleavage Catalyzed by Amphoteric Bis(acyl)guanidinium Derivatives
Authors: Göbel Michael W. , Roussev Christo D. , Scheffer Ute 
Published: February 2014

AbstractDescribed herein are two series (twelve compounds each) of very closely related guanidinium‐based receptors and their ability to catalyze hydrolytic cleavage of a unique RNA substrate – oligo‐dT flanked trans‐Activation Responsive region of the HIV‐1 mRNA, TAR RNA. The significant difference in activities of otherwise very similar compounds is discussed, and direct and indirect evidences supporting our interpretation are presented. The results indicate that improvements in catalytic efficiency could be achieved with little modification of the structure of a relatively weak catalyst, and that a crucial feature could be a finely calibrated interplay between anion‐binding and proton‐donating abilities.
Association of serum sodium with morbidity and mortality in hospitalized patients undergoing major orthopedic surgery
Authors: Mc Causland Finnian R. , Wright John , Waikar Sushrut S. 
Published: February 2014

BACKGROUNDDysnatremia may predispose to falls and fractures, and serum sodium may influence bone health. Little is known of the association of perioperative dysnatremia and clinical outcomes in those undergoing major orthopedic surgery.OBJECTIVEWe examined the association of serum sodium (corrected for glucose) with morbidity and mortality in a sample of hospitalized patients undergoing major orthopedic procedures at 2 large academic medical centers.DESIGNRetrospective observational study.SETTING AND PARTICIPANTSAdult patients admitted to major academic teaching hospitals for a major orthopedic procedure from January 2006 to January 2011.METHODSThe association of serum sodium with log‐transformed hospital length of stay was assessed by fitting linear regression models. The association with 30‐day mortality was assessed by fitting Cox proportional hazards models.RESULTSThere were 16,206 unique admissions, of which 44.8% were male, with a mean age of 62.5 years. Mean corrected serum sodium was 138.5 ± 2.9 mmol/L; 1.2% had moderate/severe hyponatremia, 6.4% had mild hyponatremia, and 2.5% were hypernatremic. In adjusted models, compared with normonatremia, moderate/severe hyponatremia, mild hyponatremia, and hypernatremia were associated with a 1.6‐, 1.4‐, and 1.4‐day‐longer hospital stay, respectively, and greater risk of 30‐day mortality (hazard ratio [HR]: 2.47, 95% confidence interval [CI]: 1.33‐4.59 for moderate/severe hyponatremia; HR: 1.80, 95% CI: 1.21‐2.66 for mild hyponatremia; and HR: 2.99, 95% CI: 1.79‐4.98 for hypernatremia).CONCLUSION AND RELEVANCEDysnatremia is relatively common in the hospitalized orthopedic population and associated with greater length of stay and 30‐day mortality. Future studies should address potential mechanisms underlying these associations and whether correction of perioperative dysnatremia may improve patient outcomes. Journal of Hospital Medicine 2014;9:297–302. © 2014 Society of Hospital Medicine