bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Polysubstituted 3‐Iodopyrans by Electrophilic Cyclization
Authors: Xie Yong‐Xin , Yan Ze‐Yi , Wang Dan‐Zhu , Wu Lu‐Yong , Qian Bo , Liu Xue‐Yuan , Liang Yong‐Min
Published: March 2009

A variety of polysubstituted 3‐iodopyrans were readily prepared in good to excellent yield under mild reaction conditions by the reaction of alkynyl carboxamides with ICl, I2, and NIS. The products obtained from this process are versatile materials that can be used to construct other complex functionalized pyran structures of importance. The occurrence of the pyranyl group in both natural products and pharmaceuticals confers important value to this study. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Binding of Nucleotides and Nucleosides to Per(6‐guanidino‐6‐deoxy)cyclodextrins in Solution
Authors: Aggelidou Chrysie , Mavridis Irene M. , Yannakopoulou Konstantina
Published: March 2009

The binding of α‐, β‐, and γ‐per(6‐guanidino‐6‐deoxy)cyclodextrins (ag, bg, and gg, respectively) with nucleotides (5′‐dAMP, 5′‐AMP, and 5′‐dCMP) and nucleosides (2′‐dA and 2′‐dC) was studied with NMR spectroscopy in aqueous solution. Nucleotides formed strong complexes with bg and gg (not ag) through ditopic binding. Multiple Coulombic attractive forces between the guanidino groups and the single phosphate group of the nucleotides drove inclusion of the entire ribose ring into the cavity, in both deoxy‐ and ribonucleotides, whereas the base moiety was only partially included. In contrast, no interaction was observed between guanidino cyclodextrins and nucleosides. The prevailing stoichiometries in all nucleotide/bg and nucleotide/gg complexes were 1:2, except for 5′‐dAMP/bg where oligomeric aggregates formed. The anti orientation of the nucleotides was preserved upon inclusion. The populations of conformers due to ribose pucker, 2′‐endo (S) and 3′‐endo (N), were practically undisturbed by inclusion. Interestingly, in the nucleotide/bg complexes at 278 K two nucleotide conformers were observed with distinctly different signals in slow mutual exchange owing to cavity restriction and a slow ribose pucker rate, which resulted in the observation of 3′‐endo (N) conformer separate from 2′‐endo (S) conformer for the first time.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Recent Advances in Organoselenium Chemistry (Eur. J. Org. Chem. 11/2009)
Authors: Freudendahl Diana M. , Shahzad Sohail A. , Wirth Thomas
Published: March 2009

The cover picture shows the Earth rising above the Moon's horizon taken in June 1969 from the Apollo 11 spacecraft. As Selene is the goddess of the moon in Greek mythology, some very recent news on selenium chemistry is shown on the Post‐It and much more is contained in the Microreview entitled Recent Advances in Organoselenium Chemistry by T. Wirth et al. on p. 1649 ff. The X‐ray structures of a selenium‐containing macrocycle (left structure, Kamigata et al.[13]) and a selenirenium ion (right structure, Poleschner et al.[67b]) shown in the foreground are taken from the literature references.
Studies on ketene and its derivatives. LXXXIII. Reaction of diketene with isoquinolinium and pyridinium methylide derivatives
Authors: Kato Tetsuzo , Chiba Takuo , Tanaka Shigeru
Published: March 2009

Reaction of isoquinolinium bis(ethoxycarbonyl)methylide (I) with diketene gave diethyl 1‐acetyl‐2,3‐dihydro‐2‐oxopyrrolo[2,1‐α]isoquinoline‐3,3‐dicarboxylate (VI), which on hydrolysis with dilute hydrochloric acid afforded ethyl 1‐acetyl‐2‐hydroxypyrrolo[2,1‐α]isoquinoline‐3‐carboxylate (IX) and ethyl 3‐methylpyrrolo[2,1‐α]isoquinoline‐3‐carboxylate (X). On the other hand, isoquinolinium cyanoethoxycarbonylmethylide (IIa) reacted with diketene to give isoquinolinium cyano(3‐ethoxycarbonyloxy‐3‐butenoyl)methylide (XIIIa) which was isomerized to isoquinolinium cyano(3‐ethoxycarbonyloxy‐2‐butenoyl)methylide (XIII). Similarly, reactions of isoquinolinium cyanomethoxycarbonylmethylide (IIb) and pyridinium cyanoalkoxycarbonyl‐methylide (IIIa,b) with diketene gave rise to the corresponding cyano(3‐alkoxycarbonyloxy‐3‐butenoyl)methylides (XIIb, XVIa,b).
N‐alkoxydipyrrylmethenes
Authors: Abramovitch R. A. , Amarnath V. , Kress R. , Molina G.
Published: March 2009

2‐Cyano‐N‐hydroxypyrroles are O‐alkylated and the nitrile function reduced to the corresponding aldehyde with diisobutylaluminum hydride. Condensation with pyrroles in the presence of hydrogen bromide gives the difficultly purified N‐alkoxydipyrrylmethanes.
Synthèse de l'analogue sélénié de la sérotonine
Authors: Laitem Léopold , Thibaut Philippe , Christiaens Léon
Published: March 2009

Nous déerivons une synthèse univoque du β‐aminoéthyl‐3 hydroxy‐5 benzo[b]sélénophène (sélénosérotonine). L'application de la réaction de Wittig à des sélénoindoxyles convenablement substitués s'est avérée une voie rapide et rentable d'accès à des amines de ce type.
Attempted synthesis of 1,4‐benzodiazepine comprising an additional ring at the 1–3 position
Authors: Klein Joseph , Golik Uri
Published: March 2009

Two possible synthetic routes leading to 1,4‐benzodiazepine derivatives comprising an additional heterocyclic ring at position 1–3 have been studied. The first approach (scheme 1) consisted in subjecting intermediates VII and XII to the Bischler‐Napieralski reaction while the second one (scheme 2) was based on intramolecular dehydration of amino ketone (XIX); both routes did however fail to yield the expected product XIII.
Synthesis of morphine‐d5 and codeine‐d8
Authors: Lawson John A. , DeGraw Joseph I. , Anbar Michael
Published: March 2009

The synthesis of morphine labeled with deuterium in the N‐methyl group and at positions 1 and 6 is described. Reduction of N‐carboethoxy‐1‐bromonorcodeinone (IV) with lithium aluminum deuteride in tetrahydrofuran‐d5 yielded the codeine‐d5. O‐Demethylation with sodium propylmercaptide‐dimethyl formamide afforded morphine‐d5, which could be remethylated with perdeuterioiodomethane to give codeine‐d8. The labeled compounds are useful as standards for field ionization mass spectrometric analysis.
Synthesis of 1‐alkyl‐5‐phenyl‐4(1H)pyrimidinones
Authors: Beck James R. , Gajewski Robert P.
Published: March 2009

1‐Alkyl‐5‐phenyl‐4(1H)pyrimidinones are readily synthesized by condensing β‐(dimethylamino)‐N‐[(dimethylamino)methylene] atropamides with methyl or ethyl amine. The latter compounds are prepared from phenylacetamides and dimethylformamide dimethyl acetal.
An easy method for the preparation of 4‐acylisoxazoles from C(α),O‐dianions of oximes
Authors: Sandifer Ronda M. , Shaffer Lynn M. , Hollinger Wayne M. , Reames David C. , Beam Charles F.
Published: March 2009

Several C(α),O‐dilithiooximes of aromatic ketones were condensed with aroyl chlorides. The presumed diacyl intermediates were not isolated, and the reaction mixtures containing them were acid‐cyclized to give 4‐acylisoxazoles in 22–62% yield.
Synthèse d'amines hétérocycliques, cancérostatiques potentiels
Authors: Thang Do Cao , Jacquignon Pierre , Dufour Michel
Published: March 2009

Nous décrivons la nitration de différents composés hétérocycliques renfermant deux atomes d'azote intranucléaires. Les structures des amines résultant de la réduction des dérivés nitrés sont précisées; les composés aminés sont actuellement testés comme cancérostatiques.
The synthesis of the benzyltetrahydropyrans
Authors: Woodyard James D. , Corbin Dale H.
Published: March 2009

The 2‐benzyl‐, 3‐benzyl‐ and 4‐benzyltetrahydropyrans have been prepared via the reaction of benzylsodium with 2‐chloro‐, 3‐bromo‐ and 4‐chlorotetrahydropyran in 49, 29 and 27% yields, respectively. The structures of these compounds were substantiated from their nmr, mass spectra and analytical data.
Photochemie von 2,5‐dihydro‐1,3,4‐oxadiazol‐2‐onen
Authors: Daniil Dimitra , Meier Herbert
Published: March 2009

Oxidation of cycloalkanone semicarbazones with lead tetraacetate leads to 2,5‐dihydro‐1,3,4‐oxadiazol‐2‐ones, which under photolytic conditions eliminate nitrogen, carbon‐monoxide and carbon dioxide. Cycloalkanones and azines are generated depending upon the solvent.
Epidemiology and genetic variability of human metapneumovirus during a 4‐year‐long study in Southeastern Brazil
Authors: Oliveira Danielle B.L. , Durigon Edison L. , Carvalho Ariane C.L. , Leal Andréa L. , Souza Thereza S. , Thomazelli Luciano M. , Moraes Claudia T.P. , Vieira Sandra E. , Gilio Alfredo E. , Stewien Klaus E.
Published: March 2009

Epidemiological and molecular characteristics of human metapneumovirus (hMPV) were compared with human respiratory syncytial virus (hRSV) in infants and young children admitted for acute lower respiratory tract infections in a prospective study during four consecutive years in subtropical Brazil. GeneScan polymerase chain assays (GeneScan RT‐PCR) were used to detect hMPV and hRSV in nasopharyngeal aspirates of 1,670 children during January 2003 to December 2006. hMPV and hRSV were detected, respectively, in 191 (11.4%) and in 702 (42%) of the children admitted with acute lower respiratory tract infections at the Sao Paulo University Hospital. Sequencing data of the hMPV F gene revealed that two groups of the virus, each divided into two subgroups, co‐circulated during three consecutive years. It was also shown that a clear dominance of genotype B1 occurred during the years 2004 and 2005, followed by genotype A2 during 2006. J. Med. Virol. 81:915–921, 2009. © 2009 Wiley‐Liss, Inc.
Fatal ongoing human cytomegalovirus reactivation during high‐dose melphalan and autologous stem cell transplantation
Authors: Focosi Daniele , Sordi Elisabetta , Papineschi Federico , Benedetti Edoardo , Galimberti Sara , Petrini Mario
Published: March 2009

Human cytomegalovirus (HCMV) reactivation can cause a wide range of complications in hematopoietic stem cell transplant recipients, ranging from pneumonia to graft failure. Although reactivations are usually seen in the early post‐transplant period, ongoing and untreated HCMV reactivation at the time of high‐dose chemotherapy and autologous stem cell support is an exceedingly rare circumstance whose consequences remain largely unknown. This case report describes a patient who underwent high‐dose melphalan and autologous transplantation with unknown active HCMV replication. J. Med. Virol. 81:857–860, 2009. © 2009 Wiley‐Liss, Inc.
Benefits of increasing the dose of influenza vaccine in residents of long‐term care facilities: A randomized placebo‐controlled trial
Authors: Cools Herman J.M. , Gussekloo Jacobijn , Remmerswaal Joyce E.M. , Remarque Ed J. , Kroes Aloys C.M.
Published: March 2009

Increased vaccine doses and mid‐season boosting may increase the proportion of residents with protective immunity from influenza in long‐term care facilities. In a multi‐center study (1997–1998), 815 residents from 14 long‐term care facilities were assigned at random to receive 15 or 30 µg of inactivated influenza vaccine, followed by a 15 µg booster vaccine or a placebo vaccine at Day 84. Seroresponses were re‐analyzed by hemagglutination‐inhibition (≥4‐fold titer increases, protective titer ≥40, geometric mean titers. Forty percent of the participants had pre‐vaccination titers ≥40. At Day 25 after vaccination, this increased to 66.3% after a 15 µg dose versus 73.3% after a dose of 30 µg (P = 0.049). Participants receiving a 30 µg dose followed by a 15 µg booster showed more ≥4‐fold titer increases at Day 109 (43.6% vs. 35.4%, P = 0.003) and protective titers ≥40 (74.2% vs. 64.6%, P = 0.041), compared to those receiving only a 15 µg dose. Differences were most apparent in participants with low pre‐vaccination titers. Booster vaccination after an initial 15 µg dose of the vaccine did not increase the protective rate (61.9% vs. 63.9% after placebo). The number of participants needed to vaccinate to protect one additional resident by a dose of 15 µg was 4, by a dose of 30 µg 3, and 15 when using a 30 µg dose instead of 15 µg. Doubling the dose of influenza vaccine increased protection‐related responses among residents of long‐term care facilities, especially in those with low pre‐vaccination titers. J. Med. Virol. 81:908–914, 2009. © 2009 Wiley‐Liss, Inc.
Epidemiological, clinical, and molecular features of norovirus infections in western India
Authors: Chhabra Preeti , Dhongade Ramchandra K. , Kalrao Vijay R. , Bavdekar Ashish R. , Chitambar Shobha D.
Published: March 2009

The study was conducted to investigate the molecular epidemiology of noroviruses (NoVs) from western India. A total of 830 fecal specimens were collected during July 2005–June 2007 from children, ≤7 years of age suffering from acute gastroenteritis in Pune, Nagpur, and Aurangabad cities. All the specimens were subjected to RT‐PCR, sequencing and phylogenetic analysis for detection and characterization of Genogroup I (GI) and GII NoVs. NoV positivity varied between 6.3% and 12.6% in different cities with the predominance of GII (96.6%). NoV infections were very common in the patients ≤2 years of age. A majority (55%) of the patients suffered from severe disease, however, vomiting was not experienced in 35%. Coinfections with rotaviruses were found in 10% cases. Summer month seasonality supported NoV infections in western India. The phylogenetic analysis of partial RNA polymerase and VP1 (capsid) genes identified 2 GI (GI. 2 and GI.6) and 5 GII (GII.4, GII.6, GII.7, GII.8, and GII.14) genetic clusters with possible occurrence of “2007 new‐variant” of GII.4. Six different combinations of RdRp and capsid genes (GII.b/GII.3, GII.b/GII.4, GII.d/GII.3, GII.b/GII.18, GII.1/GII.12 and GII.3/GII.13) were also identified. GII.4 (52%) prevailed in 2005–2006 while the predominance of probable recombinant NoV strains (58%) was noted in 2006–2007 with the contribution of GII.b/GII.3 at 79% level. GII.b/GII.18 type identified in 37% infections in 2005–2006 was completely replaced by GII.b/GII.3 type in 2006–2007. This is the first report that highlights the norovirus epidemiology and strain diversity demonstrating possible circulation of new variants in patients with acute gastroenteritis from western India. J. Med. Virol. 81:922–932, 2009. © 2009 Wiley‐Liss, Inc.
The relationship between PTSD symptom factors and emotion
Authors: Milanak Melissa E. , Berenbaum Howard
Published: March 2009

The relationship between posttraumatic stress disorder (PTSD) symptom factors and two facets of emotion were examined. Emotional congruence effects were examined using an affective priming word pronunciation (naming) task, and negative affect was measured using self‐report. Current PTSD symptoms were assessed using the Clinician‐Administered PTSD Scale in 95 adults with trauma histories. Two alternative PTSD symptom factor structures were examined, one of which included an emotional numbing factor, and one of which included a dysphoria factor. Emotional congruence effects were significantly associated with an emotional numbing factor, but not with any other PTSD factors. Negative affect was significantly associated with a dysphoria factor, but not with any other PTSD factors.
Identification and characterization of molecular targets of natural products by mass spectrometry
Authors: Cheng Ka‐Wing , Wong Chi‐Chun , Wang Mingfu , He Qing‐Yu , Chen Feng
Published: March 2009

Natural products, and their derivatives and mimics, have contributed to the development of important therapeutics to combat diseases such as infections and cancers over the past decades. The value of natural products to modern drug discovery is still considerable. However, its development is hampered by a lack of a mechanistic understanding of their molecular action, as opposed to the emerging molecule‐targeted therapeutics that are tailored to a specific protein target(s). Recent advances in the mass spectrometry‐based proteomic approaches have the potential to offer unprecedented insights into the molecular action of natural products. Chemical proteomics is established as an invaluable tool for the identification of protein targets of natural products. Small‐molecule affinity selection combined with mass spectrometry is a successful strategy to “fish” cellular targets from the entire proteome. Mass spectrometry‐based profiling of protein expression is also routinely employed to elucidate molecular pathways involved in the therapeutic and possible toxicological responses upon treatment with natural products. In addition, mass spectrometry is increasingly utilized to probe structural aspects of natural products–protein interactions. Limited proteolysis, photoaffinity labeling, and hydrogen/deuterium exchange in conjunction with mass spectrometry are sensitive and high‐throughput strategies that provide low‐resolution structural information of non‐covalent natural product–protein complexes. In this review, we provide an overview on the applications of mass spectrometry‐based techniques in the identification and characterization of natural product–protein interactions, and we describe how these applications might revolutionize natural product‐based drug discovery. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:126–155, 2010
Improved half RF slice selectivity in the presence of eddy currents with out‐of‐slice saturation
Authors: Josan Sonal , Kaye Elena , Pauly John M. , Daniel Bruce L. , Pauly Kim Butts
Published: March 2009

Ultrashort echo time imaging with half RF pulse excitation is sensitive to eddy currents induced by the slice‐select gradient that distorts the half pulse slice profile. This work demonstrates improvements in the half pulse profile by using spatial saturation on both sides of the imaged slice to suppress the out‐of‐slice magnetization. This effectively improves the selectivity of the half pulse excitation profile. A quadratic phase RF pulse with high bandwidth and selectivity was used to achieve a wide saturation band with sharp edges. Experimental results demonstrate substantially improved slice selectivity and R quantitation accuracy obtained with the out‐of‐slice saturation. This approach is effective in making short T2 imaging and quantitation with half pulses less sensitive to eddy currents. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Ghost magnetic resonance angiography
Authors: Koktzoglou Ioannis , Edelman Robert R.
Published: March 2009

Traditional methods for magnetic resonance angiography (MRA) involve the radiofrequency excitation of vascular spins within a selected region of tissue, followed by gradient localization and imaging of those spins within that same region. Signals that unfaithfully localize within the imaging volume, so‐called “ghost artifacts”, have historically been considered undesirable since they degrade image quality and every effort is made to suppress them. To the contrary, we hypothesized that these ghost artifacts could be manipulated to create detailed angiograms of the human body. In this initial demonstration of the method, which we call “Ghost MRA,” we show that the human arterial system can be depicted with exquisite anatomic detail and near total suppression of background signal. Moreover, unlike alternative unenhanced methods, Ghost MRA can be acquired without the need for cardiac synchronization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
3D single‐shot VASO using a maxwell gradient compensated GRASE sequence
Authors: Poser Benedikt A. , Norris David G.
Published: March 2009

The vascular space occupancy (VASO) method was recently proposed as a functional MRI (fMRI) method that is capable of detecting activation‐related changes in blood volume (CBV), without the need for a blood‐pool contrast agent. In the present work we introduce a new whole‐brain VASO technique that is based on a parallel‐accelerated single‐shot 3D GRASE (gradient and spin echo) readout. The GRASE VASO sequence employs a flow‐compensated correction scheme for concomitant Maxwell gradients which is necessary to avoid smearing artifacts that may occur due to violation of the Carr–Purcell–Meiboom–Gill (CPMG) condition for off‐resonance excitation. Experiments with 6 min of visual‐motor stimulation were performed on eight subjects. At P < 0.01, average percent signal change and t‐score for visual stimulation were −3.11% and −8.42, respectively; activation in left and right motor cortices and supplementary motor area was detected with −2.75% and −6.70, respectively. Sensitivity and signal changes are comparable to those of echo‐planar imaging (EPI)‐based single‐slice VASO, as indicated by additional visual‐task experiments (−3.39% and −6.93). The method makes it possible to perform whole‐brain cognitive activation studies based on CBV contrast. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Preparation and properties of poly[styrene‐co‐(butyl acrylate)‐co‐(acrylic acid)]/silica nanocomposite latex prepared using an acidic silica sol
Authors: You Bo , Wen Nangeng , Cao Yichen , Zhou Shuxue , Wu Limin
Published: March 2009

BACKGROUND: Polyacrylate/silica nanocomposite latexes have been fabricated using blending methods with silica nanopowder, in situ polymerization with surface‐functionalized silica nanoparticles or sol–gel processes with silica precursors. But these approaches have the disadvantages of limited silica load, poor emulsion stability or poor film‐forming ability.

RESULTS: In this work, poly[styrene‐co‐(butyl acrylate)‐co‐(acrylic acid)] [P(St‐BA‐AA)]/silica nanocomposite latexes and their dried films were prepared by adding an acidic silica sol to the emulsion polymerization stage. Morphological and rheological characterization shows that the silica nanoparticles are not encapsulated within polymer latex particles, but interact partially with polymer latex particles via hydrogen bonds between the silanol groups and the COOH groups at the surface of the polymer particles. The dried nanocomposite films have a better UV‐blocking ability than the pure polymer film, and retain their transparency even with a silica content up to 9.1 wt%. More interestingly, the hardness of the nanocomposite films increases markedly with increasing silica content, and the toughness of the films is not reduced at silica contents up to 33.3 wt%. An unexpected improvement of the solvent resistance of the nanocomposite films is also observed.

CONCLUSION: Highly stable P(St‐BA‐AA)/silica nanocomposite latexes can be prepared with a wide range of silica content using an acidic silica sol. The dried nanocomposite films of these latexes exhibit simultaneous improvement of hardness and toughness even at high silica load, and enhanced solvent resistance, presumably resulting from hydrogen bond interactions between polymer chains and silica particles as well as silica aggregate/particle networks. Copyright © 2009 Society of Chemical Industry
Grafting of polystyrene on carbon nanofibers by introducing a methacrylate unit
Authors: Hou Jingqiang , Zhou Xiaodong , Sui Zhijun , Zhou Xinggui
Published: March 2009

BACKGROUND: To overcome the self‐agglomeration of carbon nanofibers (CNFs), a number of studies have dealt with surface modification of CNFs to improve their wettability. In this work, a novel, simple and practical approach based on the introduction of methacrylate units to graft polymers onto the surface of CNFs is proposed.

RESULTS: The functionalized CNF samples were characterized using Fourier transform infrared and Raman spectroscopy, thermal gravimetric analysis and transmission electron microscopy. The molecular weight of grafted polystyrene (PS) is influenced by the monomer feed ratio. The stabilities of various CNF dispersions were measured using an optical analyzer. When the content of grafted PS is 34.2%, the functionalized CNFs attain a stable dispersion in xylene.

CONCLUSION: In the presence of methacrylate units, PS has been successfully grafted onto the surface of CNFs via an in situ polymerization. Moreover, the introduction of methacrylate units opens the functionalization of CNFs to other routes. Copyright © 2009 Society of Chemical Industry
Nonadditive effects of mixed crowding on protein stability
Authors: Batra Jyotica , Xu Ke , Zhou Huan‐Xiang
Published: March 2009

The crowded environments inside cells can have significant effects on the folding stability and other biophysical properties of proteins. In this study on how macromolecular crowding affects protein folding, we took a significant step toward realistically mimicking intracellular environments by using a mixture of two crowding agents, Ficoll and dextran. We found that the mixed crowding exerts a greater stabilizing effect than the sum of the two individual crowding agents. Therefore, the composition of crowders, not just the total concentration, has a significant influence on the effects of crowding on protein folding. Since the composition of intracellular macromolecules varies within the lifetime of a cell, our finding may provide an explanation for age being an important risk factor for protein aggregation‐related diseases such as Alzheimer's disease and Parkinson's disease. Proteins 2009. © 2009 Wiley‐Liss, Inc.
A dramatic conformational rearrangement is necessary for the activation of DNR from Pseudomonas aeruginosa. Crystal structure of wild‐type DNR
Authors: Giardina Giorgio , Rinaldo Serena , Castiglione Nicoletta , Caruso Manuela , Cutruzzolà Francesca
Published: March 2009

The opportunistic pathogen Pseudomonas aeruginosa can grow in low oxygen, because it is capable of anaerobic respiration using nitrate as a terminal electron acceptor (denitrification). An intermediate of the denitrification pathway is nitric oxide, a compound that may become cytotoxic at high concentration. The intracellular levels of nitric oxide are tightly controlled by regulating the expression of the enzymes responsible for its synthesis and degradation (nitrite and nitric oxide reductases). In this article, we present the crystallographic structure of the wild‐type dissimilative nitrate respiration regulator (DNR), a master regulator controlling expression of the denitrification machinery and a putative target for new therapeutic strategies. Comparison with other structures among the CRP‐FNR class of regulators reveals that DNR has crystallized in a conformation that has never been observed before. In particular, the sensing domain of DNR has undergone a rotation of more than 50° with respect to the other structures. This suggests that DNR may undergo an unexpected and very large conformational rearrangement on activation. Proteins 2009. © 2009 Wiley‐Liss, Inc.
A novel method for predicting and using distance constraints of high accuracy for refining protein structure prediction
Authors: Liu Tianyun , Horst Jeremy A. , Samudrala Ram
Published: March 2009

The principal bottleneck in protein structure prediction is the refinement of models from lower accuracies to the resolution observed by experiment. We developed a novel constraints‐based refinement method that identifies a high number of accurate input constraints from initial models and rebuilds them using restrained torsion angle dynamics (rTAD). We previously created a Bayesian statistics‐based residue‐specific all‐atom probability discriminatory function (RAPDF) to discriminate native‐like models by measuring the probability of accuracy for atom type distances within a given model. Here, we exploit RAPDF to score (i.e., filter) constraints from initial predictions that may or may not be close to a native‐like state, obtain consensus of top scoring constraints amongst five initial models, and compile sets with no redundant residue pair constraints. We find that this method consistently produces a large and highly accurate set of distance constraints from which to build refinement models. We further optimize the balance between accuracy and coverage of constraints by producing multiple structure sets using different constraint distance cutoffs, and note that the cutoff governs spatially near versus distant effects in model generation. This complete procedure of deriving distance constraints for rTAD simulations improves the quality of initial predictions significantly in all cases evaluated by us. Our procedure represents a significant step in solving the protein structure prediction and refinement problem, by enabling the use of consensus constraints, RAPDF, and rTAD for protein structure modeling and refinement. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Prion protein region 23–32 interacts with tubulin and inhibits microtubule assembly
Authors: Osiecka Katarzyna M. , Nieznanska Hanna , Skowronek Krzysztof J. , Karolczak Justyna , Schneider Gabriela , Nieznanski Krzysztof
Published: March 2009

In previous studies we have demonstrated that prion protein (PrP) binds directly to tubulin and this interaction leads to the inhibition of microtubule formation by inducement of tubulin oligomerization. This report is aimed at mapping the regions of PrP and tubulin involved in the interaction and identification of PrP domains responsible for tubulin oligomerization. Preliminary studies focused our attention to the N‐terminal flexible part of PrP encompassing residues 23–110. Using a panel of deletion mutants of PrP, we identified two microtubule‐binding motifs at both ends of this part of the molecule. We found that residues 23–32 constitute a major site of interaction, whereas residues 101–110 represent a weak binding site. The crucial role of the 23–32 sequence in the interaction with tubulin was confirmed employing chymotryptic fragments of PrP. Surprisingly, the octarepeat region linking the above motifs plays only a supporting role in the interaction. The binding of Cu2+ to PrP did not affect the interaction. We also demonstrate that PrP deletion mutants lacking residues 23–32 exhibit very low efficiency in the inducement of tubulin oligomerization. Moreover, a synthetic peptide corresponding to this sequence, but not that identical with fragment 101–110, mimics the effects of the full‐length protein on tubulin oligomerization and microtubule assembly. At the cellular level, peptide composed of the PrP motive 23–30 and signal sequence (1–22) disrupted the microtubular cytoskeleton. Using tryptic and chymotryptic fragments of α‐ and β‐tubulin, we mapped the docking sites for PrP within the C‐terminal domains constituting the outer surface of microtubule. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Synthesis and antifungal activity of 2‐azetidinonyl‐5‐(2‐benzoylphenoxy)methyl‐1,3,4‐oxadiazoles against seed‐borne pathogens of Eleusine coracana (L.) Gaertn
Authors: Khanum Shaukath A , Shashikanth Sheena , Sathyanarayana Syagadadu Giriyanna , Lokesh Siddalingaiah , Deepak Saligrama A
Published: March 2009

BACKGROUND: Finger millet is a major food crop as well as feed and fodder for livestock, especially in regions of southern India. A sturdy crop to fluctuating environmental conditions, it can be cultivated in all seasons of the year. Leaf, neck and finger blast caused by Pyricularia grisea Sacc. and Bipolaris setariae (Saw.) Shoem, as well as leaf spot disease, Bipolaris nodulosa (Berk & M.A.Curtis) Shoem, are major production constraints in southern India. Apart from environmental conditions, the use of harvested seeds by farmers is a major reason for disease prevalence. Benzophenone analogues have been investigated for controlling phytopathogenic fungi. In addition, the most important applications of azetidin‐2‐ones are as antibiotics. Based on this information, the present study was conducted to explore the antifungal activity of integrated 2‐azetidinonyl and 1,3,4‐oxadiazoles moieties into a benzophenone framework.

RESULTS: A simple high‐yielding method for the integration of heterocyclic rings, namely 2‐azetidinonyl, at the benzophenone nucleus has been achieved, starting from substituted 2‐hydroxybenzophenones under mild conditions on a wet solid surface using microwave irradiation. In the present study, an array of newly synthesised compounds, 2‐azetidinonyl‐5‐(2‐benzoylphenoxy)methyl‐1,3,4‐oxadiazoles, were screened for their antifungal property against blast and leaf spot causing fungi associated with the seeds of finger millet, cv. Indof‐9.

CONCLUSION: Two of the newly synthesised compounds showed promising effects in depleting the incidence of seed‐borne pathogenic fungi of finger millet. The suppression of Pyricularia grisea and Bipolaris setariae resulted in enhanced seed germination and seedling growth. Copyright © 2009 Society of Chemical Industry
Magnetotransport through a magnetic semiconductor single electron transistor
Authors: Lebedeva N. , Kuivalainen P.
Published: March 2009

The magnetic version of the Anderson model is applied to transport through a single electron transistor (SET), where the central region consists of a magnetic semiconductor weakly coupled to two nonmagnetic source and drain leads and a nonmagnetic gate electrode. We study theoretically magnetoresistance in a magnetic SET at various temperatures around the Curie temperature. The exchange interaction between the magnetic ions and the spins of the charge carriers causes spin disorder scattering, which results in temperature and magnetic field dependent level broadening in the central region of the SET. Consequently, a large magnetoresistance effect, whose sign and magnitude can be controlled by the gate voltage of the SET, appears at low temperatures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence of dimer lead centers in aluminium perovskites and garnets
Authors: Babin V. , Bichevin V. , Gorbenko V. , Makhov A. , Mihokova E. , Nikl M. , Vedda A. , Zazubovich S. , Zorenko Yu.
Published: March 2009

Steady‐state emission and excitation spectra and luminescence decay kinetics were studied at 80–300 K under excitation in the 2.5–6.0 eV energy range for undoped and Ce3+‐doped aluminium garnet (Lu3Al5O12, Y3Al5O12) and aluminium perovskite (LuAlO3, YAlO3) single crystalline films (SCF) grown by Liquid Phase Epitaxy method from the PbO‐based flux. The aim of the work was to identify spectral bands, arising from lead‐induced centers of different types, and to clarify their influence on scintillation characteristics of Ce3+ centers. It was found that in the perovskite SCF studied, the concentration of single Pb2+‐based centers is comparatively small. In the SCF of garnets, in YAG SCF their concentration is considerably smaller than in LuAG SCF. The lead‐induced emission at about 3.1–3.2 eV excited around 3.9 eV was observed in all the SCF studied and ascribed to the dimer lead centers of the type of {Pb2+ – oxygen vacancy – Pb2+}. In Ce3+‐doped perovskite SCF, due to a strong overlap of the excitation band of the dimer centers and the emission band of Ce3+ centers, a considerable influence of dimer lead centers on the scintillation characteristics of these materials is expected. In the SCF of garnets, the influence of dimer lead centers on the characteristics of Ce3+ centers is negligible. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Discipline‐based efforts to enhance undergraduate STEM education
Authors: Ferrini‐Mundy Joan , Güçler Beste
Published: March 2009

Initiatives designed to enhance STEM undergraduate education have much in common, as well as distinctive differences by field.
Estrogen receptor‐alpha (ER‐α) suppresses expression of its variant ER‐α36
Authors: Zou Yi , Ding Ling , Coleman Megan , Wang Zhaoyi
Published: March 2009

Recently, we identified and cloned a membrane‐based estrogen receptor (ER), ER‐α36, which is transcribed from a previously unidentified promoter in the first intron of the original ER‐α gene. We cloned the 5′ flanking region of ER‐α36 and found the cloned DNA sequence possessed strong promoter activity. A single transcription initiation site was mapped and a number of putative regulatory elements for various transcription factors such as the Wilms’ tumor suppressor, WT1 and estrogen receptor (ER) were identified in this region. Transient co‐transfection experiments further demonstrated that ER‐α suppresses ER‐α36 promoter activity in an estrogen‐independent manner, which can be released by ER‐α36 itself.
Ecological niche and potential geographic distribution of the invasive fruit flyBactrocera invadens(Diptera, Tephritidae)
Authors: De Meyer M. , Robertson M.P. , Mansell M.W. , Ekesi S. , Tsuruta K. , Mwaiko W. , Vayssières J-F , Peterson A.T.
Published: March 2009

Two correlative approaches to the challenge of ecological niche modeling (genetic algorithm, maximum entropy) were used to estimate the potential global distribution of the invasive fruit fly,Bactrocera invadens, based on associations between known occurrence records and a set of environmental predictor variables. The two models yielded similar estimates, largely corresponding to Equatorial climate classes with high levels of precipitation. The maximum entropy approach was somewhat more conservative in its evaluation of suitability, depending on thresholds for presence/absence that are selected, largely excluding areas with distinct dry seasons; the genetic algorithm models, in contrast, indicate that climate class as partly suitable. Predictive tests based on independent distributional data indicate that model predictions are quite robust. Field observations in Benin and Tanzania confirm relationships between seasonal occurrences of this species and humidity and temperature.
Consolation on Golgotha: Comforters and Sustainers of Dying Priests in England, 1580–1625
Authors: COVINGTON SARAH
Published: March 2009

The act of comforting soon-to-be executed martyrs was a collective and participatory affair in early modern England, but it was Catholics’ consolation of dying priests that resonated with a sacramental and doctrinal meaning all its own. This article seeks to highlight the late medieval traditions as well as contemporary Tridentine practices that infused such acts of comfort, particularly as they were negotiated in a time of Catholic persecution and upheaval. Of prime importance in instructing consolers, however, was Ignatius of Loyola's Spiritual exercises, which, as this essay argues, provided a guidebook for behaviour and an answer to suffering for priests and followers alike.
National Fasting and the Politics of Prayer: Anglo-Scottish Union, 1707
Authors: STEPHEN JEFFREY
Published: March 2009

From the early Reformation the Scottish Kirk had seen national public fasting as an essential exercise in furthering the spiritual, political and material well-being of the nation. For that reason fasts were held frequently, particularly at times of national crisis in Church and State. In 1706, with parliament about to deliberate on a treaty for an incorporating union with England, a national fast seemed an obvious step. The refusal of the Court party to grant a civil sanction to a fast therefore placed the issue to the forefront of national debate, providing the opposition with a major opportunity to disrupt the progress of the treaty.
Bede on the Papacy
Authors: MOORHEAD JOHN
Published: March 2009

It is clear from Bede's Historia ecclesiastica that England then enjoyed close relations with the Roman Church. Some passages in the work have been seen as reflecting a high doctrine of the papacy, but when carefully read they turn out to be devoid of any understanding of the papacy. The same is true of Bede's discussions of Christ's words to Peter (Matthew xvi.18a, 19) in his writing on the Bible. Yet other English authors of the period had attitudes very different to those of Bede; suggestions are offered as to why Bede took the line he did.
Fish composition in a south-western Atlantic temperate coastal lagoon: spatial–temporal variation and relationships with environmental variables
Authors: González Castro M. , Díaz de Astarloa J.M. , Cousseau M.B. , Figueroa D.E. , Delpiani S.M. , Bruno D.O. , Guzzoni J.M. , Blasina G.E. , Deli Antoni M.Y.
Published: March 2009

Mar Chiquita, an irregularly shaped brackish-water coastal lagoon, is located in the Buenos Aires province of Argentina and considered since 1996 by the Coordination Council of the Man and Biosphere Program of UNESCO as a World Reserve of Biosphere. The present paper aims to study both the spatial and temporal variation of fish composition in this coastal lagoon and the influence of some environmental variables on the relative abundance of the main fish species. Monthly sampling surveys over a two-year period in three different areas were conducted, using a beach-seine net and three monofilament-gill nets with different mesh size. Twenty-eight species belonging to four bio-ecological categories were identified, five of them are new records for Mar Chiquita fish community. The correspondence analysis showed strong relationships between high salinity range and the abundance of Brevoortia aurea, Cynoscion guatucupa and Pomatomus saltatrix. Conversely, low salinity range corresponded to high abundance of Mugil platanus and Odontesthes argentinensis. High temperatures were corresponded with abundance of Micropogonias furnieri and Brevoortia aurea. In contrast, high abundance of both Odontesthes argentinensis and Oligosarcus jenynsii were corresponded to low temperatures. Brevoortia aurea, Mugil platanus and Odontesthes argentinensis were the most abundant species, representing more than 80% of the total capture. The group of estuarine-nondependent-marine fish presented the highest species richness. Estuarine-dependent-marine species presented for both juveniles and adults specimens the highest abundance values.
The Impact of Market Forces on Child Care Provision: Insights from the 2005 Child Care Act in the Netherlands
Authors: NOAILLY JOËLLE , VISSER SABINE
Published: March 2009

This article examines the impact of the introduction of market forces on child care provision in the Netherlands. In January 2005, the Dutch government introduced the Child Care Act, replacing the former financing system, which had elements of both supply- and demand-financing, with a fully demand-financing system. As a result, the provision of child care is now driven by market forces. Using data on the geographical location of child care facilities, this article compares the factors affecting the provision of child care in the Netherlands before and after the introduction of the Child Care Act. The results suggest that after the regulatory reform the provision of child care has shifted towards wealthy urbanised areas, characterised by high demand and high purchasing power. This shift has largely benefited for-profit providers particularly active in these markets. In parallel, the results indicate an important drop in child care provision by non-profit organisations, most pronounced in less wealthy rural areas. These findings suggest that the introduction of demand-financing may have implications for the accessibility of child care.
A questionnaire for screening the micronutrient intake of economically active South African adults
Authors: Senekal Marjanne , Steyn Nelia P , Nel Johanna
Published: March 2009

Objective

The aim of the present study was to develop (phase 1) and validate (phase 2) a screening questionnaire to assess the adequacy of micronutrient intake of economically active South African adults.

Design

For identification of indicator foods to be included in the screening questionnaire (phase 1), a comprehensive, eighty-six-item, quantified FFQ that reflected the food sources of thirteen selected micronutrients associated with the nutrition-related health status of South Africans was developed and completed by 554 adults of all four major ethnic groups. Resulting dietary data were subjected to stepwise regression analyses to identify indicator foods to be included in the final screening questionnaire. For validation of frequency of intake reporting of specific food items included in the screening questionnaire (phase 2), a sample of sixty-six African and eighty-four white adult volunteers of both genders completed a 7 d record as well as the screening questionnaire. The frequency of intake of specific food items derived from the two methods was then compared using Spearman correlation coefficients.

Results

Phase 1 identified thirty indicator foods that formed the basis of the screening questionnaire. In phase 2, significant correlations were found for the total group for twenty-two out of the thirty items in the questionnaire, with correlations being the best for white females and the poorest for African males and females.

Conclusions

A screening questionnaire (thirty-item FFQ) that can be used by researchers and health professionals to assess an individual’s risk of inadequate micronutrient intake was developed and validated.
Isoflavone-Rich Soy Isolate Reduces Lipid Peroxidation in Mouse Liver
Authors: Ibrahim Wissam H. , Habib Hosam M. , Chow Ching K. , Bruckner Geza G.
Published: March 2009

The purpose of this study was to determine if an isoflavone-rich soy isolate affords protection against peroxidative damage in vivo. Weanling C57BL6 male mice were fed a basal diet (AIN-93G) supplemented with either nothing or 1.08 gram isoflavone-rich soy isolate/kg diet for 60 days. The soy isolate contained 400 mg/g isoflavone aglycones (226 mg/g genistein and 174 mg/g daidzein). Immediately following sacrifice liver was processed for measuring the levels of lipid peroxidation products, malondialdehyde (MDA) and conjugated dienes, and the levels of α-tocopherol, glutathione (GSH), and ascorbic acid, as well as the activities of catalase, selenium-dependent glutathione peroxidase (Se-GPx), selenium-nondependent glutathione peroxidase (non-Se-GPx), and superoxide dismutase (SOD). Compared with the control group, mice fed the diet supplemented with soy isolate had significantly (p < 0.05) lower hepatic levels of MDA and conjugated dienes. The activities of catalase and SOD were significantly increased (p < 0.05) in the liver of soy isolate-supplemented mice. The levels of vitamin E, GSH, and ascorbic acid and the activities of Se-GPx and non-Se-GPx were not significantly altered by the soy isolate. The results obtained provide experimental evidence that isoflavone supplementation confers protection against peroxidative damage to membrane lipids in vivo, possibly through enhancing the activities of the antioxidant enzymes catalase and SOD.
Global Multi‐Resolution Topography synthesis
Authors: Ryan William B. F. , Carbotte Suzanne M. , Coplan Justin O. , O'Hara Suzanne , Melkonian Andrew , Arko Robert , Weissel Rose Anne , Ferrini Vicki , Goodwillie Andrew , Nitsche Frank , Bonczkowski Juliet , Zemsky Richard
Published: March 2009

Seafloor bathymetric data acquired with modern swath echo sounders provide coverage for only a small fraction of the global seabed yet are of high value for studies of the dynamic processes of seafloor volcanism, tectonics, mass wasting, and sediment transport that create and shape the undersea landscape. A new method for compilation of global seafloor bathymetry that preserves the native resolution of swath sonars is presented. The Global Multi‐Resolution Topography synthesis consists of a hierarchy of tiles with digital elevations and shaded relief imagery spanning nine magnification doublings from pole to pole (http://www.marine‐geo.org/portals/gmrt). The compilation is updated and accessible as surveys are contributed, edited, and added to the tiles. Access to the bathymetry tiles is via Web services and with WMS‐enabled client applications such as GeoMapApp®, Virtual Ocean, NASA World Wind®, and Google Earth®.
Consistent generation of ice‐streams via thermo‐viscous instabilities modulated by membrane stresses
Authors: Hindmarsh Richard C. A.
Published: March 2009

Accurate computation of ice‐stream location and dynamics is a key aspiration for theoretical glaciology. Ice‐sheet models with thermo‐viscous coupling have been shown to exhibit stream‐like instabilities using shallow‐ice approximation mechanics, but the location and width of these streams depends on the numerical implementation and are not unique. We present results from thermo‐viscously coupled ice‐sheet models incorporating membrane stresses. Spontaneous generation of fast‐flowing linear features still occurs under certain parameter regimes, with computed stream widths between 20 km to 100 km, comparable with observations. These features are maintained as the grid‐size is decreased. The thermo‐viscous feedback mechanism that generates ice‐streams under the shallow ice approximation still operates, now selecting a unique stream size. Computations of thermo‐viscous ice flows should include membrane stresses when the bed is approximately flat, e.g. parts of Antarctica and former ice‐sheets of the Northern hemisphere. Previous calculations of spontaneous ice‐stream generation using the shallow ice approximation should be reassessed.