bluuebunny/crossref_metadata_2025_split huggingface dataset:
Versatile synthesis of self‐assembling ABA triblock copolymers with polymethyloxazoline A‐blocks and a polysiloxane B‐block decorated with supramolecular receptors
Authors: Theogarajan Luke , Desai Salil , Baldo Marc , Scholz Carmen 
Published: January 2008

AbstractBACKGROUND: Self‐assembling amphiphilic block copolymers with incorporated, biologically relevant functionalities have received limited attention, partly due to the fact that biomolecules are not robust enough to synthetic manipulation, do not lend themselves readily to systematic studies due to their complexity and leach rather quickly from a vesicle or membrane when physically incorporated. Synthetic supramolecules are used as biomolecule mimics in functional membranes.RESULTS: Reaction conditions were established for the synthesis of a tosyl‐terminated siloxane end‐blocker, which serves as molecular weight control in the synthesis of polydimethylsiloxane (PDMS) and poly(dimethylsiloxane‐co‐methylhydrosiloxane) [P(DMS‐co‐MHS)] copolymers. Hydrosilylation reactions were investigated for the covalent coupling of synthetic supramolecules (18‐crown‐6 ether, hydroxybenzoate) to the polymer backbone using the methylhydrosiloxane repeat units as the anchor moiety. Using P(DMS‐co‐MHS) or derivatized P(DMS‐co‐MHS) copolymers as macroinitiator for the ring‐opening polymerization of 2‐methyl‐4‐hydroxy‐oxazoline led to the formation of poly[(dimethylsiloxane‐co‐methylhydrosiloxane)‐block‐oxazoline] [P(DMS‐co‐MHS‐b‐Ox)] ABA triblock copolymers with defined PDMS to PMHS ratios and controlled molecular weights.CONCLUSION: Derivatized P(DMS‐co‐MHS‐b‐Ox) ABA triblock copolymers synthesized using a novel versatile procedure undergo vesicle formation upon electroformation with vesicle diameters ranging from 2 to 10 µm. The size of the vesicle depends on the overall polarity of the macromolecule. Copyright © 2008 Society of Chemical Industry
Exforge: ARB/CCB combination for better hypertension control
Authors: Chaplin Steve , McInnes Gordon 
Published: January 2008

AbstractExforge is a combination of the ARB valsartan and the CCB amlodipine to treat patients whose blood pressure is not controlled with either component. In our review, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects, and Professor McInnes comments on its role in hypertension. Copyright © 2007 Wiley Interface Ltd
Synthesis, cardiostimulatory, and cardioinhibitory effects of selected insect peptides on Tenebrio molitor
Authors: Szymanowska‐Dziubasik K. , Marciniak P. , RosińSki G. , Konopińska D. 
Published: January 2008

AbstractThe subject of these studies was a search for proctolin antagonists among peptides originating from insect species because the proctolin antagonists constantly pose a problem. During these studies we performed the synthesis of the following peptides: a native decapeptide from Manduca sexta Mas‐MT‐I and its 11 analogs with shortened sequences at the N‐end as well as a growth suppressor, a pentapeptide isolated from Antheraea yamamai, Any‐GS and its 10 analogs, modified at position 1 and with a shortened peptide chain.Biological effects were evaluated by the cardiotropic test on the semi‐isolated heart of the insect species Tenebrio molitor. Mas‐MT‐I and six analogs stimulate the heartbeat frequency, especially [6–10]‐Mas‐MT‐I, whereas the [4–10]‐Mas‐MT‐I analog shows a strong inhibition of the heartbeat frequency, if insect. The Any‐GS and the analogs [Gln1]‐ and [Gly1]‐Any‐GS also show a strong cardioinhibitory effect. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Template‐directed supramolecular assembly of a new type of nanoporous peptide‐based material
Authors: Görbitz Carl Henrik , Rise Frode 
Published: January 2008

AbstractDipeptides with two hydrophobic residues are known to often form crystals with hydrophobic or hydrophilic channels. One of the exceptions is Leu–Ile, which has been previously shown to crystallize as a nonporous 0.75 hydrate in the hexagonal space group P61 with Z′ = 4. We have now found that in the presence of D‐Leu, a second pseudopolymorph of the dipeptide is formed. The crystal structure has hydrophilic, water‐filled channels with an irregular cross section of approximately 5.5 × 3.5 Å and constitutes the first example of a crystal packing arrangement where the direction of the channels is perpendicular to the direction of hydrophobic stacking of side chains rather than parallel as in all other porous peptide‐based materials. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Deep levels associated with dislocation annihilation by Al pre‐seeding and silicon delta doping in GaN grown on Si(111) substrates
Authors: Soh C. B. , Zang K. Y. , Wang L. S. , Chow S. Y. , Chua S. J. 
Published: January 2008

AbstractThe introduction of Si burst during the growth of GaN film on Si(111) substrate by MOCVD formed a Six Ny layer which leads to an effective reduction in the density of screw dislocations. The reduction is associated with bending of screw dislocations to form a square dislocation loop when neighbouring dislocations with opposite Burger's vector paired up. The concentration of electron traps Ec–Et ∼0.17–0.26 eV which is associated with screw dislocations is substantially reduced and a kink is left at the silicon rich position. The mixed‐edge dislocation, however, is not annihilated by the Six Ny layer. Addition of TMAl burst for the AlN growth leads to a substantial reduction in trap concentration associated with the nitrogen vacancies, VN, and antisite of nitrogen, NAl, at Ec–Et ∼0.10 eV and Ec–Et ∼ 0.60 eV respectively. This improves the quality of the subsequent layer of HT‐GaN grown and is useful for device fabrication. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An electrospray ionization tandem mass spectrometric study of p‐tert‐butylcalix[6]arene complexation with ammonium hydroxide, and ammonium and sodium ions
Authors: Sassine André , Martins‐Júnior Helio A. , Lebre Daniel T. , Valli Felipe , Pires Maria A. F. , Vega Oscar , Felinto Maria C. F. C. 
Published: January 2008

AbstractThe formation of complexes involving p‐tert‐butylcalix[6]arene with neutral and charged species has been investigated by tandem mass spectrometry combined with electrospray ionization. Complexes of p‐tert‐butylcalix[6]arene with NH ions were observed in the ratios 1:1, 2:1, and 3:1, together with the complexes of p‐tert‐butylcalix[6]arene with NH4OH and Na+ ions in the ratios 1:1:1, 2:1:1, and 3:1:1. A single 1:1 complex of p‐tert‐butylcalix[6]arene with Na+ ions was observed. In addition, a doubly charged complex of p‐tert‐butylcalix[6]arene with NH4OH, Na+, and NH ions in the ratio 6:1:1:1 was observed. The identity of each complex was determined by mass analysis of product ions formed by the application of a declustering potential over the range 20–220 V and by observation of product ion mass spectra wherein the collision energy was varied from 5 to 50 eV. Fragmentation of the complexes is characterized by the facile loss of the ammonia molecule, sodium and ammonium ions, loss of neutral p‐tert‐butylcalix[6]arene, and successive neutral losses of C4H8 from the six tert‐butyl groups in each p‐tert‐butylcalix[6]arene molecule. Copyright © 2008 John Wiley & Sons, Ltd.
Sensitive determinations of stable nitrogen isotopic composition of organic nitrogen through chemical conversion into N2O
Authors: Tsunogai Urumu , Kido Tadasuke , Hirota Akinari , Ohkubo Satoru B. , Komatsu Daisuke D. , Nakagawa Fumiko 
Published: January 2008

AbstractWe present a method for high‐sensitivity nitrogen isotopic analysis of particulate organic nitrogen (PON) in seawater and freshwater, for the purpose of determining the aquatic nitrogen fixation rate through the 15N2 tracer technique for samples that contain a low abundance of organisms. The method is composed of the traditional oxidation/reduction methods, such as the oxidation of PON to nitrate (NO) using persulfate, the reduction of NO to nitrite (NO) using spongy cadmium, and further reduction of NO to nitrous oxide (N2O) using sodium azide. Then, N2O is purged from the water and trapped cryogenically with subsequent release into a gas chromatography column to analyze the stable nitrogen isotopic composition using continuous‐flow isotope ratio mass spectrometry (CF‐IRMS) by simultaneously monitoring the NO+ ion currents at masses 30, 31, and 32. The nitrogen isotopic fractionation was consistent within each batch of analysis. The standard deviation of sample measurements was less than 0.3‰ for samples containing PON of more than 50 nmolN, and 0.5‰ for those of more than 20 nmolN, by subtracting the contribution of blank nitrogen, 8 ± 2 nmol at final N2O. By using this method, we can determine δ15N for lower quantities of PON better than by other methods, so we can reduce the quantities of water samples needed for incubation to determine the nitrogen fixation rate. In addition, we can expand the method to determine the nitrogen isotopic composition of organic nitrogen in general, such as that of total dissolved nitrogen (TDN; sum of NO, NO, ammonium, and DON), by applying the method to filtrates. Copyright © 2008 John Wiley & Sons, Ltd.
Mass spectrometry and hydrogen/deuterium exchange measurements of alcohol‐induced structural changes in cellular retinol‐binding protein type I
Authors: Torta Federico , Elviri Lisa , Careri Maria , Mangia Alessandro , Cavazzini Davide , Rossi Gian Luigi 
Published: January 2008

AbstractTo bind and release its ligand, cellular retinol‐binding protein type I (CRBP) needs to undergo conformational and dynamic changes to connect the inner, solvent‐shielded cavity, where retinol is found to bind, and the outside medium. Retinol dissociation in vitro is favoured by water/alcohol mixtures whose moderately low dielectric constants mimic a property characteristic of the membrane microenvironment where this process occurs in vivo. Apo‐ and holo‐CRBP, in either water/methanol or water/trifluoroethanol (TFE) mixtures, were analyzed at equilibrium by electrospray ionization with orthogonal quadrupole time‐of‐flight mass spectrometry (ESI‐Q‐TOFMS) to identify the alcohol‐induced species. The questions were asked whether the presence of alcohols affects protein dynamics, as reflected by hydrogen/deuterium (H/D) exchange monitored by continuous‐labelling experiments, and to which extent retinol dissociation influences the process. With increasing methanol, at pH near neutrality, apo‐CRBP exhibits a progressively more compact conformation, resulting in reduced H/D exchange with respect to the native protein in water. Retinol dissociation from the holo‐protein did not promote hydrogen replacement. Similarly, in the presence of the low TFE concentration sufficient to cause retinol dissociation, the hydrogen exchange of the resulting apo‐protein was not exalted. However, in contrast with the alkanol, higher TFE concentrations induced a transition of apo‐CRBP to a new α‐helix conformation capable of exchanging all available hydrogen atoms. Copyright © 2008 John Wiley & Sons, Ltd.
Quantitative analysis of polybrominated diphenyl ethers in earthworms and soil by gas chromatography coupled to ion‐trap tandem mass spectrometry
Authors: Zhu Lingyan , Ma Baoling , Liang Xianwei 
Published: January 2008

AbstractA method coupling gas chromatography to ion‐trap tandem mass spectrometry (GC/ITMS) was developed and optimized for the analysis of polybrominated diphenyl ethers (PBDEs) in soil and earthworms. It was found that the molecular ion [M]+ cluster provided better performance than the [M‐2Br]+ as a collision‐induced dissociation (CID) precursor ion for most congeners when considering sensitivity, specificity and potential interference from complicated matrices. Other parameters such as the resonant excitation voltage, ‘q’ value, were also optimized. To evaluate the suitability of the ITMS method, the optimized method was applied for the analysis of PBDEs in different samples including earthworms and soil, and its performance was compared with that of selected ion monitoring (SIM). It was found that ITMS offered higher sensitivity than SIM when analyzing real environmental samples. Copyright © 2008 John Wiley & Sons, Ltd.
Raising cognitive load with linear multimedia to promote conceptual change
Authors: Muller Derek A. , Sharma Manjula D. , Reimann Peter 
Published: January 2008

AbstractTwo disparate research programs have addressed the challenge of instructional multimedia design. One, based on cognitive load theory, has focused on ways of reducing unnecessary cognitive load during instruction to free up resources for learning. The other, based on constructivism, has centered on interactive multimedia, allowing students to build their own knowledge. Attempting to build on both bodies of literature, in this study, we investigated techniques that can raise the useful cognitive load engendered with linear multimedia. Participating online from home, students were pre‐ and posttested around a short multimedia intervention that explained Newton's first and second laws. In Experiment 1, students who watched a video dialogue involving alternative conceptions reported investing greater mental effort and achieved higher posttest scores than students who received a standard lecture‐style presentation. In Experiment 2, two additional multimedia treatments were evaluated to assess the role of instructional time and the method of addressing alternative conceptions. In all, 272 students participated in the experiments. Interviews suggest that students adopted a more active approach to understanding the material if alternative conceptions were raised. In addition, students who watched the dialogue judged themselves to be similar to the student in the multimedia. © 2008 Wiley Periodicals, Inc.Sci Ed92:278–296, 2008
Beyond the scientific method: Model‐based inquiry as a new paradigm of preference for school science investigations
Authors: Windschitl Mark , Thompson Jessica , Braaten Melissa 
Published: January 2008

AbstractOne hundred years after its conception, the scientific method continues to reinforce a kind of cultural lore about what it means to participate in inquiry. As commonly implemented in venues ranging from middle school classrooms to undergraduate laboratories, it emphasizes the testing of predictions rather than ideas, focuses learners on material activity at the expense of deep subject matter understanding, and lacks epistemic framing relevant to the discipline. While critiques of the scientific method are not new, its cumulative effects on learners' conceptions of science have not been clearly articulated. We discuss these effects using findings from a series of five studies with degree‐holding graduates of our educational system who were preparing to enter the teaching profession and apprentice their own young learners into unproblematic images of how science is done. We then offer an alternative vision for investigative science—model‐based inquiry (MBI)—as a system of activity and discourse that engages learners more deeply with content and embodies five epistemic characteristics of scientific knowledge: that ideas represented in the form of models are testable, revisable, explanatory, conjectural, and generative. We represent MBI as an interconnected set of classroom conversations and provide examples of its implementation and its limitations. © 2008 Wiley Periodicals, Inc. Sci Ed 92:941–967, 2008
ToF‐SIMS study of 1‐dodecanethiol adsorption on Au, Ag, Cu and Pt surfaces
Authors: Laiho Taina , Leiro Jarkko A. 
Published: January 2008

AbstractTime‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) has been used to perform a chemical analysis of long‐chain thiol (CH3(CH2)11SH)‐treated gold, silver, copper and platinum surfaces. All the mass peaks from positive and negative ion spectra within the range m/z = 0–2000 u are studied. ToF‐SIMS data revealed that on gold, silver and copper substrates 1‐dodecanethiol form dense standing‐up phases, but on platinum being a catalytically active substrate, we were able to identify also surface‐aligned parallel lying molecules in addition to a standing thiolate layer. Our study shows that when ToF‐SIMS spectra are analyzed, not only the existence of oligomers but also metal + hydrocarbon fragments give information about the order of SAM. Copyright © 2008 John Wiley & Sons, Ltd.
Assessing the exposure of German and Austrian bird ringers to West Nile virus (Flavivirus) and evaluating their potential risk of infection
Authors: Linke Sonja , Muehlen Marion , Niedrig Matthias , Ellerbrok Heinz , Kaiser Andreas , Fiedler Wolfgang , Sonnenberg Karen , Alpers Katharina , Stark Klaus , Pauli Georg 
Published: January 2008

Abstract
West Nile virus (WNV) is a mosquito-borne Flavivirus with birds as its natural reservoir. Mosquitoes are able to transmit WNV to humans. In Europe, WNV is most probably imported by migrating birds from WNV-endemic regions. In this study, the risk of WNV infection during bird-ringing activities in Germany and Austria was investigated. Several serological test systems were used to study WNV antibody prevalence among 137 bird ringers. Neutralising antibodies were detected in three of the bird ringers. This seropositivity could be explained by alternative factors such as traveling to endemic areas. The application of different serological methods showed that WNV IgG ELISAs were less specific than WNV IgG immunofluorescence tests (IFT). The neutralisation test (NT) appears to be the gold standard for Flavivirus differentiation. At present, we assume that bird-ringing activity in Germany and Austria harbours a very low risk of WNV infection.
Philopatry of winter moult area in migratory Great Reed Warblers Acrocephalus
arundinaceus demonstrated by stable isotope profiles
Authors: Yohannes Elizabeth , Bensch Staffan , Lee Raymond 
Published: January 2008

Abstract
Stable carbon- (δ13C), nitrogen- (δ15N) and hydrogen (δD) isotope profiles in feathers of migratory Great Reed Warblers Acrocephalus
arundinaceus recaptured for 2 or more years in 6 successive years were examined to test whether the isotope profiles of individual warblers appeared to be consistent between years. Similar isotopic signatures in successive years suggested that individual birds tended to return and grow their feathers in Afro-tropical wintering habitats that generate similar δ13C, δ15N and δD signatures. Previous studies have shown that Great Reed Warblers exhibit strong natal and breeding philopatry, with most of the surviving birds returning to the breeding site. The present study of feather δ13C, δ15N and δD isotopic values demonstrate the year-to-year fidelity might also include the African moulting sites in this migratory species.
Perioperative Workflow: Barriers to Efficiency, Risks, and Satisfaction
Authors: Fowler Patricia H. , Craig Janet , Fredendall Lawrence D. , Damali Uzay 
Published: January 2008

ABSTRACTAN IN‐DEPTH, INTERDISCIPLINARY CASE study was conducted to map and describe the information, material, and functional processes common to high‐volume surgical specialty procedures at a southeastern US hospital.RESEARCHERS IDENTIFIED PROCESS defects and their effects using both observation and staff member interviews.OUTDATED INFORMATION and structural barriers to communications were responsible for many procedural delays, procedural interruptions, and staff member work‐arounds.OPPORTUNITIES FOR IMPROVEMENT are identified, including redesigns and enhancement of information technology systems. AORN J 87 (January 2008) 187‐208. © AORN, Inc, 2008.
Sterilization: Would Your Facility Pass a Standards Audit?
Authors: Hughes Chuck 
Published: January 2008

ABSTRACTPROPER STERILIZATION of reusable medical instruments, supplies, and devices and maintaining the sterility of these items until they are used are critical aspects of infection control. To minimize risk, perioperative managers should perform sterilization audits to test their facilities.THIS ARTICLE guides the reader through a systematic, comprehensive, sterilization audit that evaluates facility design, personnel training, and processing procedures. AORN J 87 (January 2008) 176‐182. © AORN, Inc, 2008.
Maternal consumption ofLactobacillus plantarum299v affects gastrointestinal growth and function in the suckling rat
Authors: Fåk Frida , Ahrné Siv , Molin Göran , Jeppsson Bengt , Weström Björn 
Published: January 2008

After birth, the gastrointestinal (GI) tract undergoes vast structural and functional adaptations to be able to digest mother's milk and later, during the weaning period, solid food. Studies on germ-free animals have shown the role of the gut microbiota for stimulating GI maturation, but which groups are involved is unclear. In the present study, we administered the probiotic bacterium,Lactobacillus plantarum299v (Lp299v), in the drinking water to pregnant and lactating rat dams until their pups had reached an age of 14 d. It was found that Lp299v colonizing the mothers were also able to colonize the pups, which had an impact on their gut growth and function. The small intestine, pancreas and liver weighed more in the 14 d-old pups born from dams exposed to Lp299v than in the control pups from dams given only water. Furthermore, the Lp299v pups showed decreased gut permeability. Despite a heavier spleen in the Lp299v pups, as compared to the control pups, no significant increase in the acute-phase protein, haptoglobin, was found. In conclusion, the results reported here clearly show that manipulating the maternal microflora by exposing expecting mothers to a Gram-positive, probiotic bacterium prior to parturition and during lactation impacts the gut growth and function in the offspring.
EXISTENCE OF SOLUTIONS FOR A SYSTEM INVOLVING SCHRÖDINGER OPERATORS WITH WEIGHTS
Authors: Cardoulis Laure 
Published: January 2008

AbstractIn this paper, we obtain some results on the existence of solutions for the system$$ (-\Delta+q_i)u_i=\mu_im_iu_i+f_i(x,u_1,\dots,u_n)\text{ in }\mathbb{R}^{N},\quad i=1,\dots,n, $$where each of the $q_i$ are positive potentials satisfying $\lim_{|x|\rightarrow+\infty}q_i(x)=+\infty$, each of the $m_i$ are bounded positive weights and each of the $\mu_i$ are real parameters. Depending upon the hypotheses on $f_i$, we use either the method of sub- and supersolutions or a bifurcation method.
CONSTANT MEAN CURVATURE HYPERSURFACES IN WARPED PRODUCT SPACES
Authors: Alías Luis J. , Dajczer Marcos 
Published: January 2008

AbstractWe study hypersurfaces of constant mean curvature immersed into warped product spaces of the form $\mathbb{R}\times_\varrho\mathbb{P}^n$, where $\mathbb{P}^n$ is a complete Riemannian manifold. In particular, our study includes that of constant mean curvature hypersurfaces in product ambient spaces, which have recently been extensively studied. It also includes constant mean curvature hypersurfaces in the so-called pseudo-hyperbolic spaces. If the hypersurface is compact, we show that the immersion must be a leaf of the trivial totally umbilical foliation $t\in\mathbb{R}\mapsto\{t\}\times\mathbb{P}^n$, generalizing previous results by Montiel. We also extend a result of Guan and Spruck from hyperbolic ambient space to the general situation of warped products. This extension allows us to give a slightly more general version of a result by Montiel and to derive height estimates for compact constant mean curvature hypersurfaces with boundary in a leaf.
UNITARY PROPAGATION OF OPERATOR DATA
Authors: JabŁoński Zenon J. , Stochel Jan , Szafraniec Franciszek Hugon 
Published: January 2008

AbstractWe study the problem of finding conditions which guarantee that given operator data propagate under the control of unitary operators. This is a kind of moment problem and the way we solve it is based on unitary dilations. Comparing it with other results in this area, our approach has the advantages ofallowing the data to be unbounded operators,considering arbitrary dilations, not necessarily regular ones.The relationship between the moment problem and harmonizable multivariate discrete processes is indicated.