bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving on Nature: Making a Cyclic Heptapeptide Orally Bioavailable
Authors: Nielsen Daniel S. , Hoang Huy N. , Lohman Rink‐Jan , Hill Timothy A. , Lucke Andrew J. , Craik David J. , Edmonds David J. , Griffith David A. , Rotter Charles J. , Ruggeri Roger B. , Price David A. , Liras Spiros , Fairlie David P. 
Published: September 2014

AbstractThe use of peptides in medicine is limited by low membrane permeability, metabolic instability, high clearance, and negligible oral bioavailability. The prediction of oral bioavailability of drugs relies on physicochemical properties that favor passive permeability and oxidative metabolic stability, but these may not be useful for peptides. Here we investigate effects of heterocyclic constraints, intramolecular hydrogen bonds, and side chains on the oral bioavailability of cyclic heptapeptides. NMR‐derived structures, amide H–D exchange rates, and temperature‐dependent chemical shifts showed that the combination of rigidification, stronger hydrogen bonds, and solvent shielding by branched side chains enhances the oral bioavailability of cyclic heptapeptides in rats without the need for N‐methylation.
Effect of 2‐ethylhexyl acrylate and N‐acryloylmorpholine on the properties of polyurethane/acrylic hybrid materials
Authors: Ma Guozhang , Guan Taotao , Wu Jianbing , Hou Caiying , Wang Gang , Qin Guofeng , Wang Baojun 
Published: September 2014

ABSTRACTA hybrid synthesis technology was used to prepare waterborne polyurethane/acrylic hybrid emulsions by polymerization of methyl methacrylate, butyl acrylate, 2‐ethylhexyl acrylate(EHA), and N‐acryloylmorpholine (AMCO) in presence of acrylic‐terminated PU dispersion. Various characterization methods were used to investigate the effect of EHA and ACMO content on the properties of the hybrid emulsions and their resultant films. The research results show that the introduction of EHA can enhance the elasticity of their films, meanwhile, ACMO endows the film with high gloss, adhesion on substrate, toughness, and hardness. Mixing the two monomers leads to yield the hybrid materials with moderate properties. While increasing the weight ratio of ACMO/EHA, the average particle size of the hybrid emulsions increases and their viscosity decreases. For the resultant films, their surface water contact angle, adhesion on substrates, tensile strength, and hardness increase, but the water resistance and elasticity decrease. It has been found that EHA and ACMO have a synergistic effect on gloss of the hybrid films and the hydrogen bond interaction increases with an increase in the ACMO content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41463.
Integrated interactive chart as a tool for teaching metabolic pathways
Authors: Kalogiannis Stavros , Pagkalos Ioannis , Koufoudakis Panagiotis , Dashi Ino , Pontikeri Kyriaki , Christodoulou Constantina 
Published: September 2014

AbstractAn interactive chart of energy metabolism with didactic function, complementary to the already existing metabolic maps, located at the URL www.metpath.teithe.gr is being presented. The chart illustrates the major catabolic and biosynthetic pathways of glucose, fatty acids, and aminoacids, individually as well as in an integrated view. For every metabolite and reaction an information sheet may be presented at the side of the map as fancybox, containing chemical structural formulae, an external link to the KEGG database and links that lead to the reactions at which the produced metabolites may participate as reactants. The latter allows the user to navigate through metabolic reactions following a route similar to the metabolic flow of substances, while keeping track of the occurring chemical transformations. Simultaneously, users may observe how they move across the metabolic map, possibly along different pathways, thus enhancing the user's integrated perception of metabolism. The site has already been introduced in biochemistry lectures and the students evaluated it. Most students were helped a lot or more to understand individual pathways as well as their interconnections and they also found it pleasant and easy to navigate. The vast majority of the students considered its use in the classroom desired. The chart currently may be displayed in English and in Greek while more languages can be integrated in the future. The authors' view, in accordance to the users' perception, is that the presented site may offer biochemistry tutors and students a useful teaching aid. © 2014 by The International Union of Biochemistry and Molecular Biology, 42(6):501–506, 2014.
Type 1 equilibrative nucleoside transporter regulates astrocyte‐specific glial fibrillary acidic protein expression in the striatum
Authors: Hinton David J. , Lee Moonnoh R. , Jang Jin Sung , Choi Doo‐Sup 
Published: September 2014

AbstractBackgroundAdenosine signaling has been implicated in several neurological and psychiatric disorders. Previously, we found that astrocytic excitatory amino acid transporter 2 (EAAT2) and aquaporin 4 (AQP4) are downregulated in the striatum of mice lacking type 1 equilibrative nucleoside transporter (ENT1).MethodsTo further investigate the gene expression profile in the striatum, we preformed Illumina Mouse Whole Genome BeadChip microarray analysis of the caudate–putamen (CPu) and nucleus accumbens (NAc) inENT1 null mice. Gene expression was validated byRT‐PCR, Western blot, and immunofluorescence. Using transgenic mice expressing enhanced green fluorescence protein (EGFP) under the control of the glial fibrillary acidic protein (GFAP) promoter, we examinedEGFPexpression in anENT1 null background.ResultsGlial fibrillary acidic protein was identified as a top candidate gene that was reduced in ENT1 null mice compared to wild‐type littermates. Furthermore, EGFP expression was significantly reduced in GFAP‐EGFP transgenic mice in an ENT1 null background in both the CPu and NAc. Finally, pharmacological inhibition or siRNA knockdown of ENT1 in cultured astrocytes also reduced GFAPmRNAlevels.ConclusionsOverall, our findings demonstrate thatENT1 regulatesGFAPexpression and possibly astrocyte function.
(Un)Targeted Metabolomics in Asteraceae: Probing the Applicability of Essential‐Oil Profiles of Senecio L. (Senecioneae) Taxa in Chemotaxonomy
Authors: Radulović Niko S. , Mladenović Marko Z. , Blagojević Polina D. 
Published: September 2014

AbstractThe possible applicability of (un)targeted metabolomics (volatile metabolites) for revealing taxonomic/evolutionary relationships among Senecio L. species (Asteraceae; tribe Senecioneae) was explored. Essential‐oil compositional data of selected Senecio/Senecioneae/Asteraceae taxa (93 samples in total) were mutually compared by means of multivariate statistical analysis (MVA), i.e., agglomerative hierarchical clustering and principal component analysis. The MVA input data set included the very first compositional data on the essential oil extracted from the aerial parts of S. viscosus L. as well as on four different Serbian populations of S. vernalis Waldst. & Kit. (oils from aerial parts and roots; eight samples in total). This metabolomic screening of Senecio/Senecioneae/Asteraceae species (herein presented results and data from the literature) pointed to short‐chain alk‐1‐enes (e.g., oct‐1‐ene, non‐1‐ene, and undec‐1‐ene), with up to now restricted general occurrence in Plantae, as characteristic chemotaxonomic markers/targets for future metabolomic studies of Senecio/Senecioneae taxa. The MVA additionally showed that the evolution of the terpene metabolism (volatile mono‐ and sesquiterpenoids) within the Asteraceae tribe Senecioneae was not genera specific. However, the MVA did confirm plant‐organ specific production/accumulation of volatiles within S. vernalis and suggested the existence of at least two volatile chemotypes for this species.
‘Yeast Mail’: A Novel Saccharomyces Application (NSA) to Encrypt Messages
Authors: Rosemeyer Helmut , Paululat Achim , Heinisch Jürgen J. 
Published: September 2014

AbstractThe universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)‐based, one‐step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages.
DMAEM‐based cationic polymers as novel carriers for DNA delivery into cells
Authors: Tanasienko Iryna V. , Yemets Alla I. , Finiuk Nataliya S. , Stoika Rostyslav R. , Blume Yaroslav B. 
Published: September 2014

AbstractDifferent transformation systems and vectors have been improved to increase the effectiveness of transformation and achieve stable expression of target genes. Because classical direct and indirect transformation processes commonly suffer from instability of a gene in the environment, gene deletion, transgene silencing, and poor gene transfer efficiency. Nowadays, gene transformation technologies are based on the use of new carriers (nanoparticles, carbon nanotubes, whiskers, and polymers) characterized by better efficiency and reproducibility for the direct DNA delivery into cells. In this review, we have focused on the novel DMAEM‐based direct DNA delivery system and its possible applications for cell transformation.
Cross flow microfiltration of starch nanocrystal suspensions
Authors: Romdhane Ahlem , Aurousseau Marc , Guillet Agnès , Mauret Evelyne 
Published: September 2014

AbstractStarch nanocrystals (SNC), because of their interesting barrier properties, are of great interest for the formulation of biodegradable nanocomposites. Conventional production process by acid hydrolysis results in a very low yield and a heterogeneous suspension which limits the possibility of scaling up. A continuous process that includes a microfiltration step for isolating starch nanocrystals during the hydrolysis step may be a solution to increase SNC production yield. The main objectives of this study were, first, to quantify the transmission of SNC through membranes under different operating conditions and then to identify the preponderant fouling phenomenon by using simple linear fouling models.Filtration tests were run using a lab‐scale microfiltration unit. It was equipped with ceramic membranes with a nominal pore sizes of 1.4 µm and 0.8 µm. Suspensions of nanocrystals at 0.01, 0.02 and 0.04 % (w/w) were filtered in a concentration mode under different transmembrane pressures (50, 100, and 150 kPa).Particle size analysis by Dynamic Light Scattering (DLS) showed that microfiltration is an effective tool for suspension fractionation. Mean diameter of SNC particles was reduced to less than 300 nm in permeate. The transmission through the membrane depended on operating conditions and reached 37 %. The permeate flow rate decreased with time to reach a steady value. The decrease rate was higher when the feed concentration increased. Constant pressure filtration models were used to identify the preponderant fouling phenomenon during filtration and highlighted that the decrease in permeate flow was mainly due to a cake formation on membrane surface.
Relevance of accelerated conditions for the study of monoethanolamine degradation in post‐combustion CO2 capture
Authors: Léonard Grégoire , Toye Dominique , Heyen Georges 
Published: September 2014

AbstractSolvent degradation represents one of the main operational drawbacks of the post‐combustion CO2 capture process. Degradation not only induces additional costs for solvent make‐up, it also impacts the process efficiency and its environmental penalty due to the emission of various degradation products. There is still a gap of knowledge about the influence of process operating conditions on degradation, making it currently impossible to predict the solvent degradation rate in CO2 capture plants. Morever, the reaction mechanisms corresponding to solvent degradation are very slow, significantly complicating its study in industrial units. In the present work, appropriate experimental equipment and analytical methods are developed for accelerating the degradation of monoethanolamine solvents (MEA). The relevance of accelerated conditions is established by comparing artificially degraded solvent samples with degraded solvent samples from industrial CO2 capture pilot plants. Two approaches are evaluated implying either discontinuous or continuous gas feed, this latest being the most representative of industrial degradation. The respective influences of the gas feed composition and the gas‐liquid transfer are evidenced and quantified. Finally, the present study leads to a better understanding of solvent degradation in the CO2 capture process with MEA. More generally, it also evidences that accelerated conditions at laboratory‐scale may provide relevant information for the study of slow phenomena taking place in large‐scale industrial processes. Further works include the development of a kinetic model for MEA solvent degradation and the extension of this methodology to other promising solvents in order to facilitate the operation and large‐scale deployment of CO2 capture.
A semiparametric inverse‐Gaussian model and inference for survival data with a cured proportion
Authors: Choi Sangbum , Huang Xuelin , Cormier Janice N. , Doksum Kjell A. 
Published: September 2014

AbstractThis work focuses on a semiparametric analysis of a cure rate modelling approach based on a latent failure process. In clinical and epidemiological studies, a Wiener process with drift may represent a patient's health status and a clinical endpoint occurs when the process first reaches an adverse threshold state. The first‐hitting‐time then follows an inverse‐Gaussian distribution. On the basis of the improper inverse‐Gaussian distribution, we consider a process‐based lifetime model that allows for a positive probability of no event taking place in finite time. Model flexibility is achieved by leaving a transformed time measure for disease progression completely unspecified, and regression structures are incorporated into the model by taking the acceleration factor and the threshold parameter as functions of the covariates. When applied to experiments with a cure fraction, this model is compatible with classical two‐mixture or promotion‐time cure rate models. We develop an asymptotically efficient likelihood‐based estimation and inference procedure and derive the large‐sample properties of the estimators. Simulation studies demonstrate that the proposed method performs well in finite samples. A case study of stage‐III soft tissue sarcoma data is used as an illustration. The Canadian Journal of Statistics 42: 635–649; 2014 © 2014 Statistical Society of Canada
Interdisciplinary sojourns
Authors: Rosenthal Jeffrey S. 
Published: September 2014

AbstractI was very honoured to receive the SSC 2013 Gold Medal, which caused me to reflect on different aspects of my research career. In this paper, I provide a personal reflection on those projects of mine, which could be regarded as “interdisciplinary.” I present informal summaries of my experiences with these projects, and consider possible lessons to be learned. The Canadian Journal of Statistics 42: 509–524; 2014 © 2014 Statistical Society of Canada
Glucocorticoids for bronchiolitis—should they be used?
Authors: Cohen Eyal 
Published: September 2014

AbstractEco‐paediatrics is an occasional feature in Evidence‐Based Child Health: A Cochrane Review Journal. Our goal is to contribute to the worldwide discussion on reducing waste in health care. In each instalment, we will select a recent Cochrane review highlighting a practice, still in use, which the available evidence tells us should be discontinued.
The adaptor protein SAP regulates type II NKT‐cell development, cytokine production, and cytotoxicity against lymphoma
Authors: Weng Xiufang , Liao Chia‐Min , Bagchi Sreya , Cardell Susanna L. , Stein Paul L. , Wang Chyung‐Ru 
Published: September 2014

CD1d‐restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT‐cell TCR transgenic mouse model, we demonstrated that CD1d‐expressing hematopoietic cells, but not thymic epithelial cells, meditate efficient selection of type II NKT cells. Furthermore, we showed that SAP regulates type II NKT‐cell development by controlling early growth response 2 protein and promyelocytic leukemia zinc finger expression. SAP‐deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine‐producing capacity and diminished cytotoxicity to CD1d‐expressing lymphoma cells. The impaired IL‐4 production by SAP‐deficient 24αβ T cells was associated with reduced IFN regulatory factor 4 and GATA‐3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X‐linked lymphoproliferative disease caused by mutations in SAP.
Diversity‐Oriented Synthesis of Calothrixins and Ellipticines
Authors: Dethe Dattatraya H. , Murhade Ganesh M. 
Published: September 2014

AbstractThe divergent synthesis of calothrixins and ellipticines has been accomplished by utilising the one‐pot formation of o‐diacylarenes as a key intermediate through rearrangement of o‐hydroxy ketone monoacyl hydrazones by lead tetraacetate mediated oxidation.
Dynamics of grains falling on a sloping granular medium: application to the evolution of a talus
Authors: De Blasio Fabio Vittorio , Sæter May‐Britt 
Published: September 2014

AbstractNumerous field surveys have provided quantitative information on the characteristics of talus deposits. Much less has been done to quantify the basic dynamics processes of blocks involved in talus evolution. In this work, we perform a set of experiments at the reduced scale of some metres using an inclined board covered with a loose granular medium. The complexity of the processes forming a talus is simplified by studying the interaction of only two kinds of grain sizes at a time. Grains of one class size are dropped from a fixed height onto the board covered by a layer of grains of a different class size, and their final distribution is recorded.We find that when small grains fall on large grains, the granular abundance decreases rapidly as a function of the distance from the fall point, which is explained by the effect of multiple bouncing on the irregular surface. In contrast, large grains falling on a bed of smaller grains lose much more energy at impact. They may stop at once, or roll down slope, often reaching the whole board length; as a consequence, their abundance peaks in the fall zone and at the change of slope. Experiments also show that grains travel longer with increasing fall height and sloping angle. The results clarify in a physical manner one mechanism that might explain why large blocks are typically found in the distal part of a talus slope, while smaller blocks remain near the fall zone. Based on these and previous experiments, a schematic view of talus evolution is discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Evaluation of the three-phase equilibrium method for measuring temperature dependence of internally consistent partition coefficients (KOW, KOA, and KAW) for volatile methylsiloxanes and trimethylsilanol
Authors: Xu Shihe , Kropscott Bruce 
Published: September 2014

Abstract

Partitioning equilibria and their temperature dependence of chemicals between different environmental media are important in determining the fate, transport, and distribution of contaminants. Unfortunately, internally consistent air/water (KAW), 1-octanol/air (KOA), and 1-octanol/water (KOW) partition coefficients, as well as information on their temperature dependence, are scarce for organosilicon compounds because of the reactivity of these compounds in water and octanol and their extreme partition coefficients. A newly published 3-phase equilibrium method was evaluated for simultaneous determination of the temperature dependence of KAW, KOA, and KOW of 5 volatile methylsiloxanes (VMS) and trimethylsilanol (TMS) in a temperature range from 4 °C to 35 °C. The measured partition coefficients at the different temperatures for any given compound, and the enthalpy and entropy changes for the corresponding partition processes, were all internally consistent, suggesting that the 3-phase equilibrium method is suitable for this type of measurement. Compared with common environmental contaminants reported in the literature, VMS have enthalpy and entropy relationships similar to those of alkanes for air/water partitioning and similar to those of polyfluorinated compounds for octanol/air partitioning, but more like those for benzoates and phenolic compounds for octanol/water partitioning. The temperature dependence of the partition coefficients of TMS is different from those of VMS and is more like that of alcohols, phenols, and sulfonamides. Environ Toxicol Chem 2014;33:2702–2710. © 2014 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc.
One‐Pot Regioselective Synthesis of Novel Oximino Ester‐Containing 1‐Aryl‐4‐chloro‐3‐oxypyrazoles as Potential Fungicides
Authors: Li Yi , Liu Yuan‐Yuan , Chen Nan‐Qing , Lü Kun‐Zhi , Xiong Xiao‐Hui , Li Jie 
Published: September 2014

AbstractA novel, functional‐group‐tolerant, and highly regioselective one‐pot synthesis of six 4‐chloro‐1‐aryl‐3‐oxypyrazoles, 8a–8f, containing an oximino ester moiety has been developed. Their structures were characterized by 1H‐ and 13C‐NMR, IR, MS, and elemental analyses. The regioselectivity of the reaction was also determined by single‐crystal X‐ray diffraction analysis of product 8d. The reaction pathway, proposed with the aid of DFT calculations, likely proceeds via a DMF‐catalyzed mechanism, which involves an electrophilic attack by SOCl2 and two nucleophilic substitutions by benzyl bromide (BnBr) and Cl−, respectively, as the key steps. A preliminary in vitro bioassay indicated that most compounds exhibited good fungicidal activities against Sclerotinia sclerotiorum and Gibberella zeae. Especially, 8d and 8e displayed higher or similar fungicidal activities compared with pyraclostrobin at the concentration of 10 μg/ml.