bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revisiting two sympatric European seahorse species: apparent decline in the absence of exploitation
Authors: Caldwell I.R. , Vincent A.C.J. 
Published: April 2012

ABSTRACT

Seahorses are marine fish with several life history characteristics hypothesized to make them resilient but are of conservation concern because of their international trade and habitat loss.
Surveys of two unexploited European seahorse species (Hippocampus guttulatus and Hippocampus hippocampus) in Ria Formosa lagoon, Portugal, were repeated seven years after their populations in the lagoon were found to be among the densest in the world.
Population densities of both species declined significantly between 2001/2002 and 2008/2009 surveys (94% and 73% for H. guttulatus and H. hippocampus respectively). H. guttulatus declines were not associated with any environmental changes measured (i.e. percentage live benthic habitat cover, depth, temperature, water current speed, horizontal visibility). H. hippocampus declined more where current speed had decreased.
At the low densities found in 2008/2009, occurrence for both species was best predicted by depth: seahorses were found in deeper locations throughout the lagoon. Other important predictors were temperature for H. guttulatus (found at sites warmer than average) and current speed for H. hippocampus (found in locations with faster currents).
The large declines in seahorse densities made it difficult to compare results over time. Presence–absence and abundance modelling at multiple scales can help to ensure that data are comparable even when populations fluctuate drastically.Copyright © 2012 John Wiley & Sons, Ltd.
Impacts of artificial structures on the freshwater pearl mussel Margaritifera margaritifera in the River Dee, Scotland
Authors: Cooksley Susan L. , Brewer Mark J. , Donnelly David , Spezia Luigi , Tree Angus 
Published: April 2012

ABSTRACT

Freshwater pearl mussels (Margaritifera margaritifera) in the River Dee (north‐east Scotland) are in decline, and now occur at low densities with poor recruitment levels. The population's deterioration has been attributed to reduced water quality, degraded river‐bed habitat and pearl fishing but the specific importance of each of these impacts has not previously been investigated.
This study focused on the impacts of artificial structures on the River Dee's freshwater pearl mussel population. Natural hydromorphological features were also included in the analysis. Relationships between the spatial distribution of the freshwater pearl mussel population and 31 explanatory variables were investigated using logistic regression. Three different model selection strategies were compared and contrasted.
An absence of freshwater pearl mussels was found to be significantly associated with the following factors: (1) presence of bank protection; (2) proximity of the nearest upstream bridge; (3) presence of a wastewater treatment works; (4) number of upstream tributaries; (5) proximity of the nearest upstream tributary; and (6) presence of sediment deposition.
The results strongly suggest that artificial structures on the main stem of the River Dee have contributed to the decline of its freshwater pearl mussel population. Hypotheses are proposed for the causal relationships involved. Requirements for further exploratory analyses, model testing, and experimentation are discussed.
This work opens a new line of investigation into the causes of the decline of freshwater pearl mussel populations, providing formal support at a catchment scale for an impact previously identified only on a site‐by‐site basis.Copyright © 2012 John Wiley & Sons, Ltd.
The translucent cadaver: An evaluation of the use of full body digital x‐ray images and drawings in surface anatomy education
Authors: Kotzé Sanet Henriët , Mole Calvin Gerald , Greyling Linda Magdalena 
Published: April 2012

AbstractIt has been noted by staff at the Faculty of Health Sciences, Stellenbosch University that medical students neglect the study of surface anatomy during dissection. This study reports on the novel use of Lodox® Statscan® images in anatomical education, particularly the teaching of surface anatomy. Full body digital X‐ray images (Lodox Statscan) of each cadaver (n = 40) were provided to second year medical students. During dissection students were asked to visualize landmarks, organs, and structures on the digital X‐ray and their cadaver, as well as palpate these landmarks and structures on themselves, their colleagues, and the cadaver. To stimulate student engagement with surface anatomy, dissection groups were required to draw both the normal and actual position of organs on a laminated image provided. The accuracy of the drawings was subsequently assessed and students were further assessed by means of practical identification tests. In addition, students were asked to complete an anonymous questionnaire. A response rate of 79% was obtained for the student questionnaire. From the questionnaire it was gathered that students found the digital X‐ray images beneficial for viewing most systems' organs, except for the pelvic organs. Although it appears that students still struggle with the study of surface anatomy, most students believed that the digital X‐rays were beneficial to their studies and supported their continued use in the future. Anat Sci Educ. © 2012 American Association of Anatomists.
High‐yield export of a native heterologous protein to the periplasm by the tat translocation pathway in Escherichia coli
Authors: Matos Cristina F.R.O. , Branston Steven D. , Albiniak Anna , Dhanoya Arjun , Freedman Robert B. , Keshavarz‐Moore Eli , Robinson Colin 
Published: April 2012

AbstractNumerous high‐value recombinant proteins that are produced in bacteria are exported to the periplasm as this approach offers relatively easy downstream processing and purification. Most recombinant proteins are exported by the Sec pathway, which transports them across the plasma membrane in an unfolded state. The twin‐arginine translocation (Tat) system operates in parallel with the Sec pathway but transports substrate proteins in a folded state; it therefore has potential to export proteins that are difficult to produce using the Sec pathway. In this study, we have produced a heterologous protein (green fluorescent protein; GFP) in Escherichia coli and have used batch and fed‐batch fermentation systems to test the ability of the newly engineered Tat system to export this protein into the periplasm under industrial‐type production conditions. GFP cannot be exported by the Sec pathway in an active form. We first tested the ability of five different Tat signal peptides to export GFP, and showed that the TorA signal peptide directed most efficient export. Under batch fermentation conditions, it was found that TorA‐GFP was exported efficiently in wild type cells, but a twofold increase in periplasmic GFP was obtained when the TatABC components were co‐expressed. In both cases, periplasmic GFP peaked at about the 12 h point during fermentation but decreased thereafter, suggesting that proteolysis was occurring. Typical yields were 60 mg periplasmic GFP per liter culture. The cells over‐expressed the tat operon throughout the fermentation process and the Tat system was shown to be highly active over a 48 h induction period. Fed‐batch fermentation generated much greater yields: using glycerol feed rates of 0.4, 0.8, and 1.2 mL h−1, the cultures reached OD600 values of 180 and periplasmic GFP levels of 0.4, 0.85, and 1.1 g L−1 culture, respectively. Most or all of the periplasmic GFP was shown to be active. These export values are in line with those obtained in industrial production processes using Sec‐dependent export approaches. Biotechnol. Bioeng. 2012; 109: 2533–2542. © 2012 Wiley Periodicals, Inc.
Correlation of thrombosis growth rate to pathological wall shear rate during platelet accumulation
Authors: Bark David L. , Para Andrea N. , Ku David N. 
Published: April 2012

AbstractLocal hemodynamics may strongly influence atherothrombosis, which can lead to acute myocardial infarction and stroke. The relationship between hemodynamics and thrombosis during platelet accumulation was studied through an in vitro flow system consisting of a stenosis. Specifically, wall shear rates (WSR) ranging from 0 to 100,000 s−1 were ascertained through computations and compared with thrombus growth rates found by image analysis for over 5,000 individual observation points per experiment. A positive correlation (P < 0.0001) was found between thrombus accumulation rates and WSR up to 6,000 s−1, with a decrease in growth rates at WSR >6,000 s−1 (P < 0.0001). Furthermore, growth rates at pathological shear rates were found to be two to four times greater than for physiological arterial shear rates below 400 s−1. Platelets did not accumulate for the first minute of perfusion. The initial lag time, before discernible thrombus growth could be found, diminished with shear (P < 0.0001). These studies show the quantitative increase in thrombus growth rates with very high shear rates in stenoses onto a collagen substrate. Biotechnol. Bioeng. 2012; 109: 2642–2650. © 2012 Wiley Periodicals, Inc.
Using FlAsH To Probe Conformational Changes in a Large HEAT Repeat Protein
Authors: Tsytlonok Maksym , Itzhaki Laura S. 
Published: April 2012

AbstractWe have investigated the use of FlAsH, a small fluorogenic molecule that binds to tetracysteine motifs, to probe folding of the 15‐HEAT repeat protein PR65A. PR65A is one of a special class of modular non‐globular proteins known as tandem repeat proteins, which are composed of small structural motifs that stack to form elongated, one‐dimensional architectures. We were able to introduce linear and bipartite tetracysteine motifs at several sites along the α‐helical HEAT array of PR65A without disrupting the structure or stability. When the linear tetracysteine motif CCPGCC was used, FlAsH fluorescence reported globally on the folding of the protein. When the tetracysteine motif was displayed in bipartite mode through the engineering of pairs of cysteines on adjacent HEAT repeats, FlAsH fluorescence became a reporter of local conformation and of oligomerisation. Thus, by designing FlAsH‐binding sites at different locations along the repeat array one can interrogate specific properties of PR65A, paving the way for structure–function analysis of this protein both in vitro and in the cell.
Total Synthesis of Bistramide A and Its 36(Z) Isomers: Differential Effect on Cell Division, Differentiation, and Apoptosis
Authors: Tomas Loïc , Boije af Gennäs Gustav , Hiebel Marie Aude , Hampson Peter , Gueyrard David , Pelotier Béatrice , Yli‐Kauhaluoma Jari , Piva Olivier , Lord Janet M. , Goekjian Peter G. 
Published: April 2012

AbstractThe total synthesis of bistramide A and its 36(Z),39(S) and 36(Z),39(R) isomers shows that these compounds have different effects on cell division and apoptosis. The synthesis relies on a novel enol ether‐forming reaction for the spiroketal fragment, a kinetic oxa‐Michael cyclization reaction for the tetrahydropyran fragment, and an asymmetric crotonylation reaction for the amino acid fragment. Preliminary biological studies show a distinct pattern of influence of each of the three compounds on cell division, differentiation, and apoptosis in HL‐60 cells, thus suggesting that these effects are independent activities of the natural product.
One‐Step Synthesis of SnO2 and TiO2 Hollow Nanostructures with Various Shapes and Their Enhanced Lithium Storage Properties
Authors: Wang Zhiyu , Wang Zi Chen , Madhavi Srinivasan , Lou Xiong Wen (David) 
Published: April 2012

AbstractA versatile one‐step method for the general synthesis of metal oxide hollow nanostructures is demonstrated. This method involves the controlled deposition of metal oxides on shaped α‐Fe2O3 crystals which are simultaneously dissolved. A variety of uniform SnO2 hollow nanostructures, such as nanococoons, nanoboxes, hollow nanorings, and nanospheres, can be readily generated. The method is also applicable to the synthesis of shaped TiO2 hollow nanostructures. As a demonstration of the potential applications of these hollow nanostructures, the lithium storage capability of SnO2 hollow structures is investigated. The results show that such derived SnO2 hollow structures exhibit stable capacity retention of 600–700 mAh g−1 for 50 cycles at a 0.2 C rate and good rate capability at 0.5–1 C, perhaps benefiting from the unique structural characteristics.
Enantioselective Intramolecular [2+2] Photocycloaddition Reactions of 4‐Substituted Coumarins Catalyzed by a Chiral Lewis Acid
Authors: Brimioulle Richard , Guo Hao , Bach Thorsten 
Published: April 2012

AbstractEight coumarins, which carry a terminal alkene tethered by a CH2XCH2 group to their 4‐position (X=CH2, CMe2, O, S, NBoc, NZ, NTs, NBn), were synthesized in overall yields of 51–80 %. Starting materials for the syntheses were either commercially available 4‐hydroxycoumarin or 4‐formylcoumarin. The intramolecular [2+2] photocycloaddition of these coumarins gave diastereoselectively products with a tetracyclic 3,3a,4,4a‐tetrahydro‐1H‐cyclopenta[2,3]cyclobuta[1,2‐c]chromen‐5(2H)‐one skeleton. Direct irradiation at λ=300 nm in dichloromethane (c=10 mM) led to product formation in good yields for most substrates, presumably via a singlet excited state intermediate. Due to the low coumarin absorption at λ >350 nm the photocycloaddition was slow upon irradiation at λ=366 nm. Addition of a chiral oxazaborolidine‐based Lewis acid (50 mol %) increased the reaction rate at λ=366 nm and induced a significant enantioselectivity in the [2+2] photocycloaddition. Six out of eight coumarin substrates (X=CH2, CMe2, O, NBoc, NZ, NTs) gave the respective products in yields of 72–96 % and with 74–90 % enantiomeric excess (ee) upon irradiation in dichloromethane (c=20 mM) at −75 °C. The Lewis acid presumably acts by coordination to the coumarin carbonyl oxygen atom, which leads to a bathochromic shift (redshift) of the UV absorption and which increases the singlet state lifetime. A second electrostatic interaction of the hydrogen atom at C3 with the oxygen atom of the oxazaborolidine is likely.
Solution‐Processed, Undoped, Deep‐Blue Organic Light‐Emitting Diodes Based on Starburst Oligofluorenes with a Planar Triphenylamine Core
Authors: Liu Cui , Li Yanhu , Zhang Yingyue , Yang Chuluo , Wu Hongbin , Qin Jingui , Cao Yong 
Published: April 2012

AbstractA series of starburst oligomers (T1–T3) that contained a fully diarylmethene‐bridged triphenylamine core and oligofluorene arms were designed and synthesized through Suzuki cross‐coupling reactions. Their thermal, photophysical, and electrochemical properties were also investigated. These materials showed high glass transition, in the range of 123–129 °C, and good film‐forming abilities. They displayed deep‐blue emission both in solution and as thin films. Solution‐processed devices based on these oligomers exhibited highly efficient deep‐blue electroluminescence and the device performances were significantly enhanced with the extension of the oligofluorene arms. The double‐layered device that contained T3 as an emitter showed a maximum current efficiency of 3.83 cd A−1 and a maximum external quantum efficiency of 4.19 % with CIE coordinates of (0.16, 0.09), which are among the highest values for undoped deep‐blue OLEDs that are based on solution‐processable starburst oligomers.
How Charging Corannulene with One and Two Electrons Affects Its Geometry and Aggregation with Sodium and Potassium Cations
Authors: Zabula Alexander V. , Spisak Sarah N. , Filatov Alexander S. , Grigoryants Vladimir M. , Petrukhina Marina A. 
Published: April 2012

AbstractBowl‐shaped mono‐ and dianions are prepared by reduction of corannulene (C20H10, 1) with sodium and potassium metals in the presence of [18]crown‐6 ether. Single‐crystal X‐ray diffraction studies of two sodium salts, [Na(THF)2([18]crown‐6)]+[1−] (2 a) and [Na([18]crown‐6)]+[1−] (2 b), reveal the presence of naked corannulene monoanions 1− in both cases. In contrast, the potassium adduct, [K([18]crown‐6)]+[1−] (3), shows an η2‐binding of the K+ ion to the convex face of 1−. For the first time, corannulene dianions have been isolated as salts with sodium, [Na2([18]crown‐6)]2+[12−] (4 a) and [Na(THF)2([18]crown‐6)]+[Na([18]crown‐6)]+[12−] (4 b), and potassium counterions, [K([18]crown‐6)]2+[12−] (5). Their structural characterization reveals geometry perturbations upon addition of two electrons to a bowl‐shaped polyarene. It also demonstrates η5‐ or η6‐binding of metals to the curved carbon surface of 12−, depending on the crystallization conditions. Both mono‐ and doubly‐charged corannulene bowls show the preferential exo binding of Na+ and K+ ions in all investigated compounds. Various types of CH⋅⋅⋅π interactions are found in the crystals of 2–5. The UV/Vis, ESR, and 1H NMR spectroscopic studies of 2–5 indicate different coordination environment of corannulene anions in solution, depending on the metal ion.
ChemInform Abstract: Hexatellurium Rings in Coordination Polymers and Molecular Clusters: Synthesis and Crystal Structures of [M(Te6)]X3 (M: Rh, Ir; X: Cl, Br, I) and [Ru2(Te6)] (TeBr3)4(TeBr2)2.
Authors: Guenther Anja , Ruck Michael 
Published: April 2012

AbstractBlack crystals of [Rh(Te6)]Br3 (I), [Rh(Te6)]I3 (II), [Ir(Te6)]Cl3 (III), [Ir(Te6)]Br3 (IV), and [Ir(Te6)]I3 (V) are prepared from stoichiometric mixtures of Rh or Ir, Te, and TeX4 (X: Cl, Br, I; evacuated silica tube, 300—350 °C, 7 d).
ChemInform Abstract: Structural Studies on Ba2SrMg4F14 and Ba2MM′Mg4F14 (M: Ca, Sr, Ba).
Authors: Kubel Frank , Wandl Nicole , Pantazi Mariana 
Published: April 2012

AbstractThe new compound Ba2SrMg4F14 is synthesized by precipitation from an aqueous solution of Ba(OH)2, Sr(OH)2, and Mg(OAc)2 with NH4 followed by heating at 650 °C for 3 h in a Pt crucible.
ChemInform Abstract: Cation Ordering in the Double Tungstate LiFe(WO4)2.
Authors: Albino Marjorie , Pechev Stanislav , Veber Philippe , Velazquez Matias , Josse Michael 
Published: April 2012

AbstractThe structure of the title compound is reexamined by single crystal XRD (monoclinic, space group C2/c, Z = 4).
ChemInform Abstract: Curium(III) Borate Shows Coordination Environments of Both Plutonium(III) and Americium(III) Borates.
Authors: Polinski Matthew J. , Wang Shuao , Alekseev Evgeny V. , Depmeier Wulf , Liu Guokui , Haire Richard G. , Albrecht‐Schmitt Thomas E. 
Published: April 2012

AbstractCrystals of Cm2 [B14O20(OH)7(H2O)2Cl] are prepared by reaction of CmCl3 with molten boric acid (autoclave, 240 °C, 7 d).
ChemInform Abstract: High‐Pressure Synthesis and Characterization of the Alkali Diazenide Li2N2.
Authors: Schneider Sebastian B. , Frankovsky Rainer , Schnick Wolfgang 
Published: April 2012

AbstractBlack powder of Li2N2 is prepared by decomposition of LiN3 in a Walker‐type multianvil assembly (9 GPa, 750 K, 50 min).
ChemInform Abstract: Solid‐State Structure of Bromine Azide.
Authors: Lyhs Benjamin , Blaeser Dieter , Woelper Christoph , Schulz Stephan , Jansen Georg 
Published: April 2012

AbstractBrN3 is synthesized by reaction of NaN3 with Br2 at ‐196 °C, followed by slow warming to 25 °C.
ChemInform Abstract: Nanoscale Growth of Molecular Oxides: Assembly of a {V6} Double Cubane Between Two Lacunary {P2W15} Polyoxometalates.
Authors: Lydon Claire , Busche Christoph , Miras Haralampos N. , Delf Alexander , Long De‐Liang , Yellowlees Lesley , Cronin Leroy 
Published: April 2012

AbstractThe new Wells—Dawson sandwich compound (Bu4N)10 [P4V6W30O120]·4MeCN is synthesized by refluxing (Bu4)5 [H4P2W15V3O62] in MeCN for 5 d in the dark (95% yield).
ChemInform Abstract: New Solid Solution Fe1‐xCrxVSbO6 with Rutile‐Type Structure.
Authors: Filipek E. , Dabrowska G. 
Published: April 2012

AbstractTitle solid solutions with x = 0.05, 0.25, 0.50, 0.75, and 0.90 are synthesized by solid state reaction of V2O5, α‐Sb2O4, Cr2O3, and Fe2O3 as well as from mixtures of FeVSbO6 and CrVSbO6 (620, 650, 700, 750, and 800 °C for 24 h each).
ChemInform Abstract: A New Lindqvist Polyanion‐Based Three‐Dimensional Network with a NaCl Topology.
Authors: Li Shaobin , Pang Haijun , Ma Huiyuan , Wang Kun , Zhu Chuncheng 
Published: April 2012

AbstractThe new compound [Co(bipy)3][Mo6O19]·H2O is hydrothermally synthesized from a mixture of Na2MoO4, CoCl2, NH4VO3, bipy, and H2O (autoclave, 165 °C, 5 d, 62% yield).
ChemInform Abstract: Cs2NiO2 Revisited. Crystal Structure and Magnetic Properties.
Authors: Duris Katarina , Jansen Martin 
Published: April 2012

AbstractSingle crystals of Cs2NiO2 are prepared by the azide nitrate route from mixtures of NiO and an excess of CsNO3 and CsN3 (723 K, 100 h).
ChemInform Abstract: Synthesis and Structure Determination of Ag5HgSbO6, Comparison with AgHg3SbO6 and Ag5Pb2O6.
Authors: Klein Wilhelm , Jansen Martin 
Published: April 2012

AbstractThe new compound Ag5HgSbO6 is synthesized by solid state reaction of Ag2O, HgO, and Sb2O3 (100 MPa O2, 500 °C).
ChemInform Abstract: A Further Extension of Pnictide Oxide Chemistry — Synthesis and Structure of La2AuP2O.
Authors: Eul Matthias , Moeller Manfred H. , Hoffmann Rolf‐Dieter , Jeitschko Wolfgang , Poettgen Rainer 
Published: April 2012

AbstractThe title compound is synthesized from La filings, La2O3, Au, and red P in the ratio 1.33:0.33:1:2 (pressed pellets, evacuated silica tube, 1473 K, 48 h).
ChemInform Abstract: Development of an Intramolecular Gassman′s [2 + 2] Cycloaddition.
Authors: Feltenberger John B. , Ko Changhong , Deng Jun , Ghosh Sunil K. , Hsung Richard P. 
Published: April 2012

AbstractThe reaction of different oxygen‐, nitrogen‐, and carbon‐tethered acetals gives rise to fused cyclobutane derivatives.
ChemInform Abstract: Heterocyclization of 3‐(R‐Amino)‐3‐methylthio‐1‐phenylpropenones (I) and 5‐Benzoyl‐6‐methylthio‐1,2‐dihydropyridin‐2‐ones (X) with 1,2‐ and 1,3‐Dinucleophilic Reagents.
Authors: Britsun V. N. , Pikun N. V. , Ryabitskii A. B. , Lozinskii M. O. 
Published: April 2012

AbstractReactions of the title compounds (I) and (X) with N,N‐, N,C‐1,2‐ and 1,3‐dinucleophiles proceed regioselectively via [3 + 2]‐ or [3 + 3]cyclocondensation, in general.
ChemInform Abstract: Reactions of 3‐Aroylacrylates with α‐Aminoazoles.
Authors: Kolos N. N. , Kovalenko L. U. , Borovskoy V. A. 
Published: April 2012

AbstractCyclocondensation of 3‐aroylacrylates with α‐aminoazoles provides access to azolopyridine and ‐pyrimidine derivatives.
ChemInform Abstract: Unexpected Tandem Reaction of New Type Morita—Baylis—Hillman Adducts Promoted by [Hmim]HSO4/NaNO3 System.
Authors: Zhong Weihui , Wang Guan , Chen Kai 
Published: April 2012

AbstractA tandem reaction of Baylis—Hillman adducts (I) proceeds in the ionic liquid [Hmim]HSO4 / NaNO3 system and the unexpected products (III) and (IV) are formed via rearrangement and substitution.
ChemInform Abstract: Sodium Borohydride—Nickel Chloride—Methanol Catalytic System for Regioselective Reduction of Electron‐Rich Conjugated Dienes and Reductive Cleavage of Allyl Esters Involving π‐Allylnickel Intermediates.
Authors: Yin Biao‐Lin , Cai Cong‐Bi , Lai Jin‐Qiang , Zhang Ze‐Ren , Huang Li , Xu Li‐Wen , Jiang Huan‐Feng 
Published: April 2012

AbstractThe chemoselective reduction of one double bond of various electron‐rich dienes, e.g. (I), (III), (V) and (XI) is smoothly achieved in the system NaBH4—NiCl2—MeOH.
ChemInform Abstract: A Simple and Efficient Bromoformyloxylation and Bromoacetoxylation Reaction Using TsNBr2.
Authors: Saikia Indranirekha , Rajbongshi Kamal Krishna , Phukan Prodeep 
Published: April 2012

AbstractReaction of a variety of olefins with DMF in the presence of TosNBr2 followed by hydrolysis offers a method for the regioselective synthesis of O‐formyl bromohydrins.
ChemInform Abstract: Nitrite Ionic Liquids (IL‐ONO and [bmim]NO2) as Effective Nitrosonium Sources for the Synthesis of α‐Oximinoketones under Mild Heterogeneous Conditions.
Authors: Valizadeh H. , Shomali A. , Gholipour H. 
Published: April 2012

Abstract[bmim]NO2 is similarly efficient as nitrosonium source.