bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: The Enantiospecific Synthesis of Chromans and Isochromans Using a Variant of an Intramolecular Nicholas Reaction.
Authors: Tyrrell Elizabeth , Mazloumi Khatebeh , Banti Donatella , Sajdak Paulina , Sinclair Alex , Le Gresley Adam
Published: November 2012

During the attempt to deprotect the dioxolane (I) in order to get an aldehyde structure as precursor of a benzopyran skeleton, formation of a chromanone (II) is observed.
ChemInform Abstract: Sulfated Titania Catalyzed Water‐Mediated Efficient Synthesis of Dicoumarols — A Green Approach.
Authors: Karmakar Bikash , Nayak Anupam , Banerji Julie
Published: November 2012

The process allows the preparation of various biologically interesting dicoumarols under mild conditions.
ChemInform Abstract: An Efficient One‐Pot Synthesis of Coumarins Mediated by Propylphosphonic Anhydride (T3P) via the Perkin Condensation.
Authors: Augustine John Kallikat , Bombrun Agnes , Ramappa Balakrishna , Boodappa Chandrakantha
Published: November 2012

The mild and low toxic coupling agent T3P allows the synthesis of various functionalized coumarin structures.
ChemInform Abstract: Solvent‐Free Synthesis of 4‐Aryl‐3,4‐dihydrobenzopyran‐2‐ones via [3 + 3] Cyclocoupling of Phenols with Cinnamic Acid Catalyzed by Molecular Iodine.
Authors: Kamat Durga P. , Tilve Santosh G. , Kamat Vijayendra P.
Published: November 2012

The method allows the preparation of various synthetically important dihydrocoumarin derivatives in acceptable yields.
ChemInform Abstract: Enantioselective Asymmetric Michael Addition of Cyclic Diketones to β,γ‐Unsaturated α‐Keto Esters.
Authors: Wang Yi‐Feng , Wang Ke , Zhang Wei , Zhang Bin‐Bin , Zhang Chi‐Xiao , Xu Dan‐Qian
Published: November 2012

The resulting chiral Michael adducts are of high biological and pharmaceutical value.
ChemInform Abstract: Synthesis of Coumarins via Pechmann Reaction Catalyzed by 3‐Methyl‐1‐sulfonic Acid Imidazolium Hydrogen Sulfate as an Efficient, Halogen‐Free and Reusable Acidic Ionic Liquid.
Authors: Khaligh Nader Ghaffari
Published: November 2012

Acidic ionic liquid [Msim]HSO4 is used as an efficient catalyst for Pechmann condensation reaction.
ChemInform Abstract: Facile Catalyzed Preparation of 14‐Aryl‐ or Alkyl‐14‐H‐dibenzo[a,j]xanthenes by Dodecylphosphonic Acid and Dodecylsulfamic Acid: Environmentally Benign Methods.
Authors: Ghassamipour Soheila , Sardarian Ali Reza
Published: November 2012

A one‐pot synthesis provides the target compounds under mild‐ and solvent‐free conditions in good to moderate yields.
ChemInform Abstract: Coupling of Enamides with Alkynes or Arynes for Synthesis of Substituted Pyridines and Isoquinolines via Amide Activation.
Authors: Zhao Mi‐Na , Ren Zhi‐Hui , Wang Yao‐Yu , Guan Zheng‐Hui
Published: November 2012

Derivative (I) can also react with diethyl instead of dimethyl acetylenedicarboxylate.
ChemInform Abstract: Regioselective Assembly of 3,4‐Dihydroisoquinoline Derivatives.
Authors: Gao Zhongli , Davis Larry , Chiang Yulin , Munson Randall , Hendrix James A.
Published: November 2012

The facile two‐step sequence allows the synthesis of the title compounds as substructures of alkaloids and drugs.
ChemInform Abstract: Friedel—Crafts‐Type Reactions with Ureas and Thioureas.
Authors: Raja Erum K. , Lill Sten O. Nilsson , Klumpp Douglas A.
Published: November 2012

Intra‐ and intermolecular reactions are promoted by TfOH, where the former are generally more efficient.
ChemInform Abstract: N‐Bromosuccinimide as an Efficient Catalyst for the Synthesis of Indolo[2,3‐b]quinolines.
Authors: Ghorbani‐Vaghei Ramin , Malaekehpoor Seyedeh Mina
Published: November 2012

NBS promotes the synthesis of title compounds (III), (V), (VII), and (IX) in good yields in the reaction of various aryl amines (II), (IV) (VI), and (VIII) with indol‐3‐carbaldehyde (I).
ChemInform Abstract: Stereocontrolled Oxidative Additions upon N‐Alkyl‐1,4‐dihydropyridines: Synthesis of Hexahydrofuro[2,3‐b]pyridine Derivatives.
Authors: Kumar Rakesh , Kumar Dhiraj , Prasad Ashok K.
Published: November 2012

N‐Halosuccinimide‐promoted addition of allyl alcohol to dihydropyridines (I) results in regio‐ and stereoselective formation of trans‐2‐alkoxy‐3‐halotetrahydropyridines, which undergo radical cyclization furnishing hexahydrofuropyridine derivatives (IV).
ChemInform Abstract: Intrinsic Catalytic Activity of an Acidic Ionic Liquid as a Solvent for Quinazoline Synthesis.
Authors: Patil Vikas S. , Padalkar Vikas S. , Chaudhari Amol S. , Sekar N.
Published: November 2012

Quinazoline derivatives are synthesized using the ionic liquid as solvent and catalyst which can be recycled and reused for further conversions.
ChemInform Abstract: Three‐Component Sequential Synthesis of N,N′‐Disubstituted 5‐Arylidenedihydropyrimidine‐2,4‐dione.
Authors: Bellucci Maria Cristina , Volonterio Alessandro
Published: November 2012

A three‐component sequential process consists of (i) in situ formation of carbodiimides by Staudinger reaction, (ii) reaction with aryl propenoic acids (III) and (iii) final cyclization of the resulting N‐acylurea intermediates, e.g. (VI), to afford title compounds (IV).
ChemInform Abstract: Synthesis of New Substituted 1,2,4‐Triazines from Isonitrosoketones and Terephthalaldehydedihydrazone.
Authors: Alici Onder , Karatas Ibrahim
Published: November 2012

The symmetric derivatives (III) are obtained via condensation of keto oximes (II) with terephthalohydrazone.
ChemInform Abstract: A Facile Synthesis of Novel Dihydroindeno[1,2‐e][1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines Using HTIB.
Authors: Prakash Om , Aneja Deepak Kumar , Wadhwa Deepak , Kumar Ravi , Arora Sanjiv
Published: November 2012

Cyclocondensation of 2‐tosyloxyindanones (III), which are readily accessible through hypervalent iodine oxidation of indanones (I) with 4‐amino‐5‐mercaptotriazoles, affords the title triazolothiadiazines (V) (21 examples) in good yield.
ChemInform Abstract: Iridium Catalyzed Asymmetric Hydrogenation of Cyclic Imines of Benzodiazepinones and Benzodiazepines.
Authors: Gao Kai , Wu Bo , Yu Chang‐Bin , Chen Qing‐An , Ye Zhi‐Shi , Zhou Yong‐Gui
Published: November 2012

Optically active heterocyclic systems are formed which are of biological interest.
ChemInform Abstract: Lithium Trihydroxy/Triisopropoxy‐2‐pyridylborate Salts (LTBS): Synthesis, Isolation, and Use in Modified Suzuki—Miyaura Cross‐Coupling Reactions.
Authors: Chen Kuanchiang , Peterson Richard , Math Shivanand K. , LaMunyon James B. , Testa Charles A. , Cefalo Dustin R.
Published: November 2012

Heteroaryl halides react with borate (II) to give the corresponding salts (III) or salts (VII) after hydrolysis.
ChemInform Abstract: The Influence of Perfluorinated Substituted on the Nucleophilic Reactivities of Silyl Enol Ethers.
Authors: Laub Hans A. , Gladow Daniel , Reissig Hans‐Ulrich , Mayr Herbert
Published: November 2012

The nucleophilic reactivity of the silyl enol ethers is reduced by introduction of perfluorinated alkyl and aryl groups (up to 8 orders of magnitude).
ChemInform Abstract: Convenient Preparation of Long‐Chain Dialkyl Phosphates: Synthesis of Dialkyl Phosphates.
Authors: Aitken R. Alan , Collett Chris J. , Mesher Shaun T. E.
Published: November 2012

The approach includes controlled reaction of POCl3 with alcohols and subsequent careful hydrolysis of the resulting dialkyl chlorophosphates with steam.
ChemInform Abstract: Isolation and Structure of a Novel Biindole Pigment Substituted with an Ethyl Group from a Metagenomic Library Derived from the Marine Sponge Halichondria okadai.
Authors: Abe Takahiro , Kukita Akira , Akiyama Kiyotaka , Naito Takayuki , Uemura Daisuke
Published: November 2012

isolation and structure elucidation of the yellow pigment, halichrome A (I) which shows cytotoxicity against B16 melanoma cells
ChemInform Abstract: Microwave‐Assisted Novel and Efficient One‐Pot Synthesis of Fused Steroidal and Non‐Steroidal Isothiazoles.
Authors: Bezbaruah Pranjal , Gogoi Junali , Rao Kommuri S. , Gogoi Pranjal , Boruah Romesh C.
Published: November 2012

Various steroidal isothiazoles are prepared from the corresponding β‐bromo‐α,β‐unsaturated aldehydes.
ChemInform Abstract: Synthesis of Strained Cyclic Peptides via an Aza‐Michael—Acyl‐Transfer Reaction Cascade.
Authors: Rutters Jochem P. A. , Verdonk Yvette , de Vries Remko , Ingemann Steen , Hiemstra Henk , Levacher Vincent , van Maarseveen Jan H.
Published: November 2012

The reaction proceeds through an esterification of the C‐terminus of a dipeptide with the corresponding auxiliaries and the subsequent lactam formation by an intramolecular aza‐Michael‐acyl‐transfer reaction cascade.
ChemInform Abstract: Synthesis of N‐Urethane Protected α‐Aminoalkyl‐α′‐cyanomethyl Ketones; Application to the Synthesis of 3‐Substituted 5‐Amino‐1H‐pyrazole Tethered Peptidomimetics.
Authors: Sharnabai M. K. , Nagendra G. , Sureshbabu Vommina V.
Published: November 2012

Starting from previously reported amino acid derived bromoketones (I), the synthesis of pyrazoles of type (IV) via the cyanomethylketones (III) is developed and their incorporation into peptidomimetics is described.
ChemInform Abstract: Practical Demethylation of Podophyllotoxin and Efficient Preparation of 4‐Amino‐4‐deoxy‐4′‐demethylepipodophyllotoxin.
Authors: Guminski Yves , Grousseaud Martial , Cugnasse Sandrine , Imbert Thierry
Published: November 2012

The regioselective demethylation of podophyllotoxin (I) is smoothly achieved using methionine and methylsulfonic acid in TFA or in acetone/water.
ChemInform Abstract: Optimization of Imidazole Compounds as Selective TAAR1 Agonists: Discovery of RO5073012.
Authors: Galley Guido , Stalder Henri , Goergler Annick , Hoener Marius C. , Norcross Roger D.
Published: November 2012

Based on 2‐benzylimidazoline screening hits, low molecular weight imidazole compounds are identified as potent, selective, and drug‐like TAAR1 agonists.
ChemInform Abstract: Crystal Structures and Second‐Order NLO Properties of Borogermanates
Authors: Zhang Jian‐Han , Kong Fang , Xu Xiang , Mao Jiang‐Gao
Published: November 2012

Review: 69 refs.
ChemInform Abstract: Reactive Halogen Chemistry in the Troposphere
Authors: Saiz‐Lopez Alfonso , von Glasow Roland
Published: November 2012

Review: 296 refs.
ChemInform Abstract: Nanoporous Gold as a Platform for a Building Block Catalyst
Authors: Wittstock Arne , Wichmann Andre , Baumer Marcus
Published: November 2012

Review: 146 refs.
ChemInform Abstract: Nickel, Palladium and Platinum
Authors: Dervisi Athanasia
Published: November 2012

Review: 99 refs.
ChemInform Abstract: Perylenequinones: Isolation, Synthesis, and Biological Activity
Authors: Mulrooney Carol A. , O'Brien Erin M. , Morgan Barbara J. , Kozlowski Marisa C.
Published: November 2012

Review: ca. 150 refs.
ChemInform Abstract: Enzyme‐Responsive Polymeric Assemblies, Nanoparticles and Hydrogels
Authors: Hu Jinming , Zhang Guoqing , Liu Shiyong
Published: November 2012

Review: 92 refs.
ChemInform Abstract: Advanced Supramolecular Polymers Constructed by Orthogonal Self‐Assembly
Authors: Li Shao‐Lu , Xiao Tangxin , Lin Chen , Wang Leyong
Published: November 2012

Review: 61 refs.
ChemInform Abstract: Self‐Assembly of Block Copolymers
Authors: Mai Yiyong , Eisenberg Adi
Published: November 2012

Review: 100 refs.
ChemInform Abstract: Covalent Organic Frameworks
Authors: Feng Xiao , Ding Xuesong , Jiang Donglin
Published: November 2012

Review: 64 refs.
ChemInform Abstract: Stimuli‐Responsive Supramolecular Polymeric Materials
Authors: Yan Xuzhou , Wang Feng , Zheng Bo , Huang Feihe
Published: November 2012

Review: 303 refs.
ChemInform Abstract: Supramolecular Gels Formed from Multi‐Component Low Molecular Weight Species
Authors: Buerkle Lauren E. , Rowan Stuart J.
Published: November 2012

Review: 67 refs.
ChemInform Abstract: Nanocomposites and Macroscopic Materials: Assembly of Chemically Modified Graphene Sheets
Authors: Wu Dongqing , Zhang Fan , Liang Haiwei , Feng Xinliang
Published: November 2012

Review: 230 refs.
ChemInform Abstract: Supramolecular Polymeric Hydrogels
Authors: Appel Eric A. , del Barrio Jesus , Loh Xian Jun , Scherman Oren A.
Published: November 2012

Review: 264 refs.
ChemInform Abstract: Heterogeneous Bifunctional Metal/Acid Catalysts for Selective Chemical Processes
Authors: Barbaro Pierluigi , Liguori Francesca , Linares Neomi , Moreno Marrodan Carmen
Published: November 2012

Review: about 200 refs.
ChemInform Abstract: Laboratory Studies of Organic Peroxy Radical Chemistry: An Overview with Emphasis on Recent Issues of Atmospheric Significance
Authors: Orlando John J. , Tyndall Geoffrey S.
Published: November 2012

Review: 224 refs.
ChemInform Abstract: Nighttime Radical Observations and Chemistry
Authors: Brown Steven S. , Stutz Jochen
Published: November 2012

Review: 487 refs.
ChemInform Abstract: The Overhanging Carboxylic Acid Strategy — An Alternative Route to the Porphyrin Core Expansion/Modification for the Coordination of Large Metal Ions
Authors: Le Gac Stephane , Boitrel Bernard
Published: November 2012

Review: 35 refs.
ChemInform Abstract: Synthesis of Glycosylated Metal Phthalocyanines and Naphthalocyanines
Authors: Lyubimtsev Alexey , Iqbal Zafar , Crucius Goeran , Syrbu Sergey , Ziegler Thomas , Hanack Michael
Published: November 2012

Review: 64 refs.
ChemInform Abstract: Polychlorotriphenylmethyl Radicals: Towards Multifunctional Molecular Materials
Authors: Veciana Jaume , Ratera Imma
Published: November 2012

Review: 225 refs.
ChemInform Abstract: Asymmetric Catalysis
Authors: Bergin Enda
Published: November 2012

Review: 53 refs.
ChemInform Abstract: Applications of Nanocatalyst in New Era
Authors: Chaturvedi Shalini , Dave Pragnesh N. , Shah N. K.
Published: November 2012

Review: 236 refs.
ChemInform Abstract: Hybrid Organic—Inorganic Structured Materials as Single‐Site Heterogeneous Catalysts
Authors: Diaz Urbano , Boronat Mercedes , Corma Avelino
Published: November 2012

Review: 86 refs.
ChemInform Abstract: Rational Design of Single‐Site Heterogeneous Catalysts: Towards High Chemo‐, Regio‐ and Stereoselectivity
Authors: Dal Santo Vladimiro , Guidotti Matteo , Psaro Rinaldo , Marchese Leonardo , Carniato Fabio , Bisio Chiara
Published: November 2012

Review: 100 refs.
ChemInform Abstract: Band Bending in Semiconductors: Chemical and Physical Consequences at Surfaces and Interfaces
Authors: Zhang Zhen , Yates, John T. Jr.
Published: November 2012

Review: 256 refs.
ChemInform Abstract: Kinetics, Products, and Mechanisms of Secondary Organic Aerosol Formation
Authors: Ziemann Paul J. , Atkinson Roger
Published: November 2012

Review: 200 refs.
ChemInform Abstract: Chemistry and Biology of the Ubiquitin Signal
Authors: Spasser Liat , Brik Ashraf
Published: November 2012

Review: 216 refs.
ChemInform Abstract: Particles, Air Quality, Policy and Health
Authors: Heal Mathew R. , Kumar Prashant , Harrison Roy M.
Published: November 2012

Review: 342 refs.
ChemInform Abstract: Protein Microarrays for Genome‐Wide Posttranslational Modification Analysis
Authors: Merbl Yifat , Kirschner Marc W.
Published: November 2012

Review: 76 refs.
ChemInform Abstract: Probability Distribution Function of the Order Parameter. Mixing Fields and Universality
Authors: Plascak J. A. , Martins P. H. L.
Published: November 2012

Review: 53 refs.
ChemInform Abstract: Schwinger Boson Approaches to Quantum Antiferromagnetism
Authors: Auerbach Assa , Arovas Daniel P.
Published: November 2012

Review: 17 refs.
ChemInform Abstract: Chemical Signals of Past Climate and Environment from Polar Ice Cores and Firn Air
Authors: Wolff Eric W.
Published: November 2012

Review: 69 refs.
ChemInform Abstract: Exploring the Complexity of Aerosol Particle Properties and Processes Using Single Particles Techniques
Authors: Krieger Ulrich K. , Marcolli Claudia , Reid Jonathan P.
Published: November 2012

Review: 259 refs.
ChemInform Abstract: Functional in vivo EPR Spectroscopy and Imaging Using Nitroxide and Trityl Radicals
Authors: Khramtsov Valery V. , Zweier Jay L.
Published: November 2012

Review: 155 refs.
ChemInform Abstract: Magnetic Resonance Force Microscopy
Authors: Barbic Mladen
Published: November 2012

Review: 63 refs.
ChemInform Abstract: Multidimensional Earth′s‐Field NMR
Authors: Halse Meghan E. , Coy Andrew , Dykstra Robin , Eccles Craig D. , Hunter Mark W. , Callaghan Paul T.
Published: November 2012

Review: 25 refs.
Magnetism‐Tunable Oligoacene Dioxide Diradicals: Promising Magnetic Oligoacene‐Like Molecules
Authors: Yang Hongfang , Han Li , Zhao Jing , Song Xinyu , Song Qisheng , Bu Yuxiang
Published: November 2012

Graphene oxide has attracted intense research interest recently because the graphene oxide synthesis route, as a promising alternative for cost‐effective mass production of graphene, has been explored. To further study the oxidation process and possible mechanism and to explore applicability of the oxidized products, we have performed a computational study on three series of oligoacene dioxides, focusing on their structures and electronic properties. Taking 1,5‐dioxidized naphthalene as a starting point, three series of oligoacene dioxides are considered as follows: 1) middle insertion by 1–2 benzene rings; 2) single‐side expansion using 1–2 benzene rings; 3) double‐side expansion using two benzene rings. On the basis of density functional theory and complete active space self‐consistent field (CASSCF) calculations, we reveal that oligoacene dioxides in the middle insertion series have a triplet ground state, whereas those in the single‐side expansion series and the double‐side expansion series have open‐shell broken‐symmetry singlet diradical ground states except for their common origin naphthalene‐1,5‐dioxide whose ground state is triplet and which is also viewed as the origin of the middle insertion series. Magnetic coupling interactions of these oligoacene dioxides are also determined. This work should help people toward an atomistic understanding of the electronic structures and properties of possible intermediates or products and even the oxidation mechanism of graphene sheets, and provides a reasonable strategy of designing novel graphene‐oxide‐based magnetic materials.
Synthesizing VHDL from Activity Models in UML 2
Authors: Balderas‐Contreras Tomás , Cumplido René , Rodríguez Gustavo
Published: November 2012

This document describes a synthesis technology that generates structural VHDL code from models describing the flow of data required to perform algorithms operating on bit‐blocks. The models are built using restricted activity diagrams in the Unified Modeling Language version 2. The code generator is developed using Acceleo, a technology to implement transformations from models to text. The technology described in this paper exploits the principles of object orientation and model‐driven engineering. The primary aim is to improve productivity and alleviate complexity during the design of digital hardware systems that implement demanding operations used by a wide variety of computing devices. The use of the technology is illustrated with the generation of VHDL code from models describing a block cipher algorithm. Copyright © 2012 John Wiley & Sons, Ltd.
Security flaws in two improved remote user authentication schemes using smart cards
Authors: Ma Chun‐Guang , Wang Ding , Zhao Sen‐Dong
Published: November 2012

Understanding security failures of cryptographic protocols is the key to both patching existing protocols and designing future schemes. In this paper, we analyze two recent proposals in the area of password‐based remote user authentication using smart cards. First, we point out that the scheme of Chen et al. cannot achieve all the claimed security goals and report its following flaws: (i) it is vulnerable to offline password guessing attack under their nontamper resistance assumption of the smart cards; and (ii) it fails to provide forward secrecy. Then, we analyze an efficient dynamic ID‐based scheme without public‐key operations introduced by Wen and Li in 2012. This proposal attempts to overcome many of the well‐known security and efficiency shortcomings of previous schemes and supports more functionalities than its counterparts. Nevertheless, Wen–Li's protocol is vulnerable to offline password guessing attack and denial of service attack, and fails to provide forward secrecy and to preserve user anonymity. Furthermore, with the security analysis of these two schemes and our previous protocol design experience, we put forward three general principles that are vital for designing secure smart‐card‐based password authentication schemes: (i) public‐key techniques are indispensable to resist against offline password guessing attack and to preserve user anonymity under the nontamper resistance assumption of the smart card; (ii) there is an unavoidable trade‐off when fulfilling the goals of local password update and resistance to smart card loss attack; and (iii) at least two exponentiation (respectively elliptic curve point multiplication) operations conducted on the server side are necessary for achieving forward secrecy. The cryptanalysis results discourage any practical use of the two investigated schemes and are important for security engineers to make their choices correctly, whereas the proposed three principles are valuable to protocol designers for advancing more robust schemes. Copyright © 2012 John Wiley & Sons, Ltd.
Neck circumference is correlated with triglycerides and inversely related with HDL cholesterol beyond BMI and waist circumference
Authors: Vallianou Natalia G. , Evangelopoulos Angelos A. , Bountziouka Vassiliki , Vogiatzakis Evangelos D. , Bonou Maria S. , Barbetseas John , Avgerinos Petros C. , Panagiotakos Demosthenes B.
Published: November 2012

Background

Neck circumference, beyond a measure of obesity, is a unique fat depot with increasing significance. This study aimed to investigate the association between neck circumference and biomarkers, indicators of cardiovascular risk.

Methods

During 2009, 490 volunteers (46 ± 16 years, 40% men) were consecutively enrolled to the study (participation rate 85%). Biochemical analyses were performed through established procedures, and after 12‐h fasting and glucose, total cholesterol, high‐density lipoprotein and low‐density lipoprotein cholesterol, triglycerides, cystatin C, uric acid and high‐sensitivity C‐reactive protein were measured. Anthropometric, lifestyle and dietary characteristics were also recorded to account for potential confounders. Additive linear and logistic regression models were used to evaluate the association between neck circumference and biomarkers of cardiometabolic risk.

Results

A positive association between neck circumference and systolic and diastolic blood pressure, glucose, triglycerides, uric acid and high‐sensitivity C‐reactive protein, and a negative association with high‐density lipoprotein cholesterol were revealed (all ps < 0.05); models were adjusted for age, gender, years of school, smoking, physical activity status, MedDietScore and alcohol intake. The relationship between neck circumference and high‐density lipoprotein cholesterol, glucose, triglycerides and uric acid remained significant when models were further stratified by body mass index class and abnormal waist circumference.

Conclusion

Neck circumference was found to be a powerful indicator of atherogenic dyslipidaemia above and beyond central obesity indicators. Copyright © 2012 John Wiley & Sons, Ltd.
Trophic transfer of biodiversity effects: functional equivalence of prey diversity and enrichment?
Authors: Behl Stephan , de Schryver Vera , Diehl Sebastian , Stibor Herwig
Published: November 2012

Producer diversity is frequently assumed to be detrimental to herbivores, because less edible taxa are more likely to dominate diverse communities. Many producers are, however, complementary in their resource use, and primary production is often positively related to producer diversity. We performed an experiment with microalgae and a generalist herbivore to explore the hypothesis that such positive effects are transferred up the food chain and are functionally comparable to effects of enrichment with a limiting resource. In both absence and presence of grazers, primary production was positively affected by both light supply and producer diversity. Survival, reproduction, and biomass of herbivores were also positively affected by light supply and producer diversity, with both factors contributing equally to grazer performance. We conclude that producer diversity can indeed have similar positive effects on secondary production as enrichment with a limiting resource and discuss conditions under which such positive effects are likely to dominate over negative ones.
Gut microbiota regulates NKG2D ligand expression on intestinal epithelial cells
Authors: Hansen Camilla H. F. , Holm Thomas L. , Krych Łukasz , Andresen Lars , Nielsen Dennis S. , Rune Ida , Hansen Axel K. , Skov Søren
Published: November 2012

Intestinal epithelial cells (IECs) are one of a few cell types in the body with constitutive surface expression of natural killer group 2 member D (NKG2D) ligands, although the magnitude of ligand expression by IECs varies. Here, we investigated whether the gut microbiota regulates the NKG2D ligand expression on small IECs. Germ‐free and ampicillin‐treated mice were shown to have a significant increase in NKG2D ligand expression. Interestingly, vancomycin treatment, which propagated the bacterium Akkermansia muciniphila and reduced the level of IFN‐γ and IL‐15 in the intestine, decreased the NKG2D ligand expression on IECs. In addition, a similar increase in A. muciniphila and a decreased NKG2D ligand expression was seen after feeding with dietary xylooligosaccharides. A pronounced increase in NKG2D ligand expression was furthermore observed in IL‐10‐deficient mice. In summary, our results suggest that the constitutive levels of NKG2D ligand expression on IECs are regulated by microbial signaling in the gut and further disfavor the intuitive notion that IEC NKG2D ligand expression is caused by low‐grade immune reaction against commensal bacteria. It is more likely that constitutively high IEC NKG2D ligand expression is kept in check by an intestinal regulatory immune milieu induced by members of the gut microbiota, for example A. muciniphila.
First Synthesis of the Pyrano‐Naphthoquinone Lactone (–)‐Arizonin C1 (Eur. J. Org. Chem. 25/2011)
Authors: Mahlau Manuel , Fernandes Rodney A. , Brückner Reinhard
Published: November 2012

The cover picture shows buttes in the world‐famous Monument Valley. Located on the Arizona/Utah border, this place helps to pinpoint smallish Tuba City halfway down the road to Flagstaff. In 1988, members of the Anti‐Infective Division of Abbott Laboratories screened that town's soil for unknown microorganisms. Their discovery of Actinoplaces arizonaensis and its antibiotics, arizonin A1, A2, B1, B2, C1, and C3, allowed us to select arizonin C1 as a target. Our synthesis began with a Dötz benzannulation, and the stereocenters were implanted by a Sharpless dihydroxylation (>99 % ee) and an oxa‐Pictet–Spengler cyclization. Details are discussed in the article by R. Brückner et al. on p. 4765 ff. Photography credits: Wolfgang Staudt (http://www.flickr.com/photos/wolfgangstaudt/2200558634/); design credits: Dipl.‐Chem. Frank Sartorius (Universität Freiburg).
Square Wave Electroanalysis at Generator–Collector Gold–Gold Double Hemisphere Junctions
Authors: Lewis Grace E. M. , Dale Sara E. C. , Kasprzyk‐Hordern Barbara , Barnes Edward O. , Compton Richard G. , Marken Frank
Published: November 2012

Gold–gold double‐hemisphere junction electrodes with an inter‐electrode gap of typically 1 µm are employed for generator–collector square wave voltammetry. Electrochemical data are recorded as a function of both generator and collector potential to give three‐dimensional response “maps”. At sufficiently low frequencies, close‐to‐steady‐state conditions for the collector response are achieved and peak responses complementary to those for the generator electrode are recorded. Due to localised interelectrode gap diffusion (fast) as opposed to peripheral diffusion (slow), information about reaction products and intermediates can be obtained. Local pH gradient effects provide additional “fingerprint” information beneficial for future application in analytical detection.
A non‐conforming least‐squares finite element method for incompressible fluid flow problems
Authors: Bochev Pavel , Lai James , Olson Luke
Published: November 2012

In this paper, we develop least‐squares finite element methods (LSFEMs) for incompressible fluid flows with improved mass conservation. Specifically, we formulate a new locally conservative LSFEM for the velocity–vorticity–pressure Stokes system, which uses a piecewise divergence‐free basis for the velocity and standard C0 elements for the vorticity and the pressure. The new method, which we term dV‐VP improves upon our previous discontinuous stream‐function formulation in several ways. The use of a velocity basis, instead of a stream function, simplifies the imposition and implementation of the velocity boundary condition, and eliminates second‐order terms from the least‐squares functional. Moreover, the size of the resulting discrete problem is reduced because the piecewise solenoidal velocity element is approximately one‐half of the dimension of a stream‐function element of equal accuracy. In two dimensions, the discontinuous stream‐function LSFEM [1] motivates modification of our functional, which further improves the conservation of mass. We briefly discuss the extension of this modification to three dimensions. Computational studies demonstrate that the new formulation achieves optimal convergence rates and yields high conservation of mass. We also propose a simple diagonal preconditioner for the dV‐VP formulation, which significantly reduces the condition number of the LSFEM problem. Published 2012. This article is a US Government work and is in the public domain in the USA.
Large‐scale DMFC Stack Model: Feed Disturbances and Their Impact on Stack Performance
Authors: McIntyre J. , Kulikovsky A. A. , Müller M. , Stolten D.
Published: November 2012

A highly scalable quasi‐3D model of a large 1‐kW class direct methanol fuel cell stack is developed. The model takes into account in‐plane heat and current transport in the bipolar plates, coupled to the through‐plane transport in the membrane‐electrode assemblies. The electro chemical model is an extension of a Perry–Newman–Cairns model with the Butler–Volmer rate of electrochemical conversion. The stack is ”cut” into a large number of elementary geometrical units and each unit is solved on a separate core using supercomputing resources. The model is used to simulate the regimes of stack operation with methanol flow failures in part of the cell. The results show that the full‐fed domain of the cell takes over part of the load of the starved domain, which homogenizes the distribution of all parameters over the defect cell surface.
Flow‐Field Designs of Bipolar Plates in PEM Fuel Cells: Theory and Applications
Authors: Wang J. , Wang H.
Published: November 2012

A generalized model developed by Wang was modified for flow field designs of the most common layout configurations with U‐type arrangement, including single serpentine, multiple serpentine, straight parallel, and interdigitated configurations. A direct and quantitative relationship was established among flow distribution, pressure drop, configurations, structures, and flow conditions. The model was used for a direct, systematic, and quantitative comparison of flow distributions and pressure drops among the most common layout configurations of interest. The straight parallel configuration had the lowest pressure drops but suffered the most possibility of the uneven flow distribution across the channels. The single serpentine had the best flow distribution but had the highest pressure drops. The flow distribution and the pressure drop in the multiple serpentine was between the straight parallel and the single serpentine. Finally, we suggested basic criteria of the flow field designs of bipolar plates for the industrial applications. This provides a practical guideline to evaluate how far a fuel cell is from design operating conditions, and measures how to improve flow distribution and pressure drop.
Behavioral disturbances differentiate frontotemporal lobar degeneration subtypes and Alzheimer's disease: evidence from the Frontal Behavioral Inventory
Authors: Konstantinopoulou Eleni , Aretouli Eleni , Ioannidis Panagiotis , Karacostas Dimitrios , Kosmidis Mary H.
Published: November 2012

Background

Behavioral assessment is useful for the diagnosis of frontotemporal lobar degeneration (FTLD). We explored the ability of the Frontal Behavioral Inventory (FBI) to discriminate between patients with distinct subtypes of FTLD and patients with Alzheimer's disease (AD), as well as the influence of demographic variables on FBI scores.

Methods

The FBI was administered to the caregivers of 87 patients diagnosed with FTLD [64 behavioral variant FTLD, 19 aphasic variant FTLD (primary progressive aphasia), and 4 motor/extrapyramidal variant (corticobasal syndrome)] and 30 patients with AD. Patients with AD were older than patients with FTLD. The two groups did not differ with respect to duration of illness, level of education, or sex ratio.

Results

Age significantly predicted disinhibited positive behaviors, such as perseverations and irritability, whereas education did not contribute to FBI ratings. Classification accuracy for the discrimination of AD and mixed FTLD groups was 81%. Moreover, 88.3% and 83.7% accuracy was achieved for the discrimination of AD and behavioral variant FTLD, and AD and primary progressive aphasia groups, respectively. The Total Negative subscale of the FBI, which summarizes the presence of deficit (negative) behaviors, was the best discriminator. A cut‐off score of 17 provided 83% sensitivity and 98% specificity in distinguishing between FTLD and AD patients.

Conclusions

The FBI is a sensitive and specific tool for the differential diagnosis of FTLD from AD. The optimal cut‐off point for the detection of FTLD patients was lower than that initially proposed. Copyright © 2012 John Wiley & Sons, Ltd.
Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster® 550 in Rats: An Exploratory Assessment
Authors: Patisaul Heather B. , Roberts Simon C. , Mabrey Natalie , McCaffrey Katherine A. , Gear Robin B. , Braun Joe , Belcher Scott M. , Stapleton Heather M.
Published: November 2012

Firemaster® 550 (FM 550), a fire‐retardant mixture used in foam‐based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 µg/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels. #x000A9; 2012 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:124‐136, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21439
Osteocalcin: Skeletal and extra‐skeletal effects
Authors: Neve Anna , Corrado Addolorata , Cantatore Francesco Paolo
Published: November 2012

Osteocalcin (OC) is a non‐collagenous, vitamin K‐dependent protein secreted in the late stage of osteoblasts differentiation. The presence of the three residues of γ‐carbossiglutamatic acid, specific of the active form of OC protein, allows the protein to bind calcium and consequently hydroxyapatite. The osteoblastic OC protein is encoded by the bone γ‐carbossiglutamate gene whose transcription is principally regulated by the Runx2/Cbfa1 regulatory element and stimulated by vitamin D3 through a steroid‐responsive enhancer sequence. Even if data obtained in literature are controversial, the dual role of OC in bone can be presumed as follows: firstly, OC acts as a regulator of bone mineralization; secondly, OC regulates osteoblast and osteoclast activity. Recently the metabolic activity of OC, restricted to the un‐carboxylated form has been demonstrated in osteoblast‐specific knockout mice. This effect is mediated by the regulation of pancreatic β‐cell proliferation and insulin secretion and adiponectin production by adipose tissue and leads to the regulation of glucose metabolism and fat mass. Nevertheless, clinical human studies only demonstrated the correlation between OC levels and factors related to energy metabolism. Thus further investigations in humans are required to demonstrate the role of OC in the regulation of human energy metabolism. Moreover, it is presumable that OC also acts on blood vessels by inducing angiogenesis and pathological mineralization. This review highlights the recent studies concerning skeletal and extra‐skeletal effects of OC. J. Cell. Physiol. 228: 1149–1153, 2013. © 2012 Wiley Periodicals, Inc.
Blood‐Derived Stem Cells (BDSCs) plasticity: In vitro hepatic differentiation
Authors: Alaimo Giorgia , Cozzoli Eliana , Marfe Gabriella , Esposito Luca , Ranalli Marco , Hmada Dalya , Giordano Antonio , Gambacurta Alessandra
Published: November 2012

The limited availability of hepatic tissue suitable for the treatment of liver disease and drug research encourages the generation of hepatic‐like cells from alternative sources as support for the regenerative medicine. Human blood derived stem cells (BDSCs) express surface markers and genes characteristic of pluripotent stem cells and have the ability to differentiate into different cell types, including tissues of endodermal origin (i.e., liver). Therefore they can represent a valuable source of hepatocytes for medicine. In this investigation, we exploited a fast hepatic differentiation protocol to generate hepatocyte‐like cells from human BDSCs using only hepatocyte growth factor (HGF) and fibroblast growth factor‐4 (FGF‐4) as growth factors. The resulting cell population exhibited hepatic cell‐like morphology and it was characterized with a variety of biological endpoint analyses. Here, we demonstrate how human BDSCs can be reprogrammed in hepatocyte‐like cells by morphological, functional analysis, reverse transcriptase (RT)‐PCR, and Western Blot assay. This study defines a fast and easy reprogramming strategy that facilitates the differentiation of human BDSCs along a hepatic lineage and provides a framework for a helpful source in the stem cells therapy and liver disorders. J. Cell. Physiol. 228: 1249–1254, 2013. © 2012 Wiley Periodicals, Inc.
miR‐197 induces epithelial–mesenchymal transition in pancreatic cancer cells by targeting p120 catenin
Authors: Hamada Shin , Satoh Kennichi , Miura Shin , Hirota Morihisa , Kanno Atsushi , Masamune Atsushi , Kikuta Kazuhiro , Kume Kiyoshi , Unno Jun , Egawa Shinichi , Motoi Fuyuhiko , Unno Michiaki , Shimosegawa Tooru
Published: November 2012

Invasive ductal adenocarcinoma (IDA) of the pancreas manifests poor prognosis due to the early invasion and distant metastasis. In contrast, intraductal papillary mucinous adenoma or carcinoma (IPMA or IPMC) reveals better clinical outcomes. Various molecular mechanisms contribute to these differences but entire picture is still unclear. Recent researches emphasized the important role of miRNA in biological processes including cancer invasion and metastasis. We previously described that miR‐126 is down‐regulated in IDA compared with IPMA or IPMC, and miR‐126 regulates the expression of invasion related molecule disintegrin and metalloproteinase domain‐containing protein 9 (ADAM9). Assessing the difference of miRNA expression profiles of IDA, IPMA, and IPMC, we newly identified miR‐197 as an up‐regulated miRNA specifically in IDA. Expression of miR‐197 in pancreatic cancer cells resulted in the induction of epithelial–mesenchymal transition (EMT) along with the down‐regulation of p120 catenin which is a putative target of miR‐197. Direct interaction between miR‐197 and p120 catenin mRNA sequence was confirmed by 3′UTR assay, and knockdown of p120 catenin recapitulated EMT induction in pancreatic cancer cells. In situ hybridization of miR‐197 and immunohistochemistry of p120 catenin showed mutually exclusive patterns suggesting pivotal role of miR‐197 in the regulation of p120 catenin. This miR‐197/p120 catenin axis could be a novel therapeutic target. J. Cell. Physiol. 228: 1255–1263, 2013. © 2012 Wiley Periodicals, Inc.
Ontogeny and homology of the skeletal elements that form the sucking disc of remoras (Teleostei, Echeneoidei, Echeneidae)
Authors: Britz Ralf , Johnson G. David
Published: November 2012

The sucking disc of the sharksuckers (Echeneidae) is one of the most remarkable and most highly modified skeletal structures among vertebrates. In this issue of the Journal of Morphology, Britz and Johnson (pp. 1353–1366) report about their study of the development of the sucking disc based on a series of larval, juvenile, and adult echeneids. They aim at answering the question of the homology of the different skeletal parts that form the disc. The cover image shows the head and sucking disc of a 26.7 mm long juvenile marlinsucker, Remora osteochir, in frontal view. Remoras use their sucking disc to attach to larger marine animals and several remora species are host specific. Remora osteochir prefers spearfishes as hosts, in particular sailfish and white marlin. The striking sucking disc of remoras is homologous to the spinous dorsal fin of other spiny‐rayed fishes. The skeleton of the disc is formed in development through the enormous expansion of both the bases of the fin spines and the distal radial elements of the fin supports.
Evaluation of the ion trap MS performance for quantification of flavonoids and comparison to UV detection
Authors: Stanoeva Jasmina Petreska , Stefova Marina
Published: November 2012

The application of an ion trap mass spectrometer, usually employed for identification, has been here systematically evaluated for quantitative analysis of various conjugated forms of flavonoids and compared with UV quantification.

Three MS methods were tested to assess the potential and limits of the ion trap for quantification of flavonoids: full‐scan experiment MS2, isolated ion experiment MS, and full‐scan experiment MS. The test was performed using nine reference standards of flavonoids with six different aglycones: luteolin, apigenin, hypolaetin, 4′‐O‐methylhypolaetin, isoscutellarein and 4′‐O‐methylisoscutellarein in the form of 7‐O‐glucosides and diglucosides, mono or diacetylated, isolated from Sideritis scardica. The analytical characteristics of the tested MS methods were shown to be comparable to UV with regards to precision and accuracy, and superior for selectivity and sensitivity especially when using extracted ion chromatograms. Detection limits did not differ significantly between the MS methods but were significantly lower than those obtained with UV detection by one order of magnitude.

Another issue addressed by these results was the choice of most suitable standard substances for quantification of flavonoids with various substituents attached when using MS. In UV detection, the nature of the aglycone is crucial for the absorbance properties, and various derivatives can be quantified with the available one with the same aglycone. Here, it was shown that in MS detection, one flavone derivative can be quantified using other available derivatives with similar substitution pattern with regards to attached and acetylated sugars, whereas the nature of the aglycone is not crucial. Copyright © 2012 John Wiley & Sons, Ltd.
Surfactant protein B amount and kinetics in newborn infants: an optimized procedure
Authors: Simonato Manuela , Baritussio Aldo , Vedovelli Luca , Lamonica Giulia , Carnielli Virgilio Paolo , Cogo Paola Elisa
Published: November 2012

Surfactant protein B (SP‐B) plays a key role in surfactant homeostasis affecting its biophysical properties and physiological function.

Recently, a method to measure SP‐B amount and kinetics from tracheal aspirates (TAs) became available. The main objective of this study was to improve the critical steps of the procedure to obtain a better SP‐B sensitivity.

We administered a 24 h continuous infusion of 1 mg/kg/h of 113 C‐leucine to ten newborn infants. SP‐B was isolated from serial TAs and its fractional synthesis rate, secretion time, peak time and half life were derived from 13 C enrichment curves obtained by gas chromatography mass spectrometry. SP‐B amount in TAs was also assessed.

During the extraction step, acidification and organic solvent ratio optimization doubled the recovery of SP‐B from TAs, so did the elongation of the propylation time (from 20 min to 1 h) with enhanced leucine derivatization yield.

Measurement of 13 C leucine enrichments, and therefore all SP‐B kinetics parameters, were successfully calculated in all TAs samples due to the increase of SP‐B yield.

SP‐B amount was 0.29 (0.16–0.41) % of total phospholipids with a minimum value of 0.08% belonging to one of the respiratory distress syndrome (RDS) patients.

In conclusion, this new procedure enables accurate determination of SP‐B kinetics even in the presence of low protein amount like in preterm RDS patients. Copyright © 2012 John Wiley & Sons, Ltd.
The native cell population does not contribute to central‐third graft healing at 6, 12, or 26 weeks in the rabbit patellar tendon
Authors: Kinneberg Kirsten R.C. , Galloway Marc T. , Butler David L. , Shearn Jason T.
Published: November 2012

Investigators do not yet understand the role of intrinsic tendon cells in healing at the tendon‐to‐bone enthesis. Therefore, our first objective was to understand how the native cell population influences tendon autograft incorporation in the central‐third patellar tendon (PT) defect site. To do this, we contrasted the histochemical and biomechanical properties of de‐cellularized patellar tendon autograft (dcPTA) and patellar tendon autograft (PTA) repairs in the skeletally mature New Zealand white rabbit. Recognizing that soft tissues in many animal models require up to 26 weeks to incorporate into bone, our second objective was to investigate how recovery time affects enthesis formation and graft tissue biomechanical properties. Thus, we examined graft structure and mechanics at 6, 12, and 26 weeks post‐surgery. Our results showed that maintaining the native cell population produced no histochemical or biomechanical benefit at 6, 12, or 26 weeks. These findings suggest that PTA healing is mediated more by extrinsic rather than intrinsic cellular mechanisms. Moreover, while repair tissue biomechanical properties generally increased from 6 to 12 weeks after surgery, no further improvements were noted up to 26 weeks. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 638–644, 2013