bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo magnetic resonance elastography of human brain at 7 T and 1.5 T
Authors: Hamhaber Uwe , Klatt Dieter , Papazoglou Sebastian , Hollmann Maurice , Stadler Jörg , Sack Ingolf , Bernarding Johannes , Braun Jürgen 
Published: September 2010

AbstractPurpose:To investigate the feasibility of quantitative in vivo ultrahigh field magnetic resonance elastography (MRE) of the human brain in a broad range of low‐frequency mechanical vibrations.Materials and Methods:Mechanical vibrations were coupled into the brain of a healthy volunteer using a coil‐driven actuator that either oscillated harmonically at single frequencies between 25 and 62.5 Hz or performed a superimposed motion consisting of multiple harmonics. Using a motion sensitive single‐shot spin‐echo echo planar imaging sequence shear wave displacements in the brain were measured at 1.5 and 7 T in whole‐body MR scanners. Spatially averaged complex shear moduli were calculated applying Helmholtz inversion.Results:Viscoelastic properties of brain tissue could be reliably determined in vivo at 1.5 and 7 T using both single‐frequency and multifrequency wave excitation. The deduced dispersion of the complex modulus was consistent within different experimental settings of this study for the measured frequency range and agreed well with literature data.Conclusion:MRE of the human brain is feasible at 7 T. Superposition of multiple harmonics yields consistent results as compared to standard single‐frequency based MRE. As such, MRE is a system‐independent modality for measuring the complex shear modulus of in vivo human brain in a wide dynamic range. J. Magn. Reson. Imaging 2010;32:577–583. © 2010 Wiley‐Liss, Inc.
Association between contrast‐enhanced MR images and blood–brain barrier disruption following transcranial focused ultrasound
Authors: Yang Feng‐Yi , Horng Shih‐Cheng , Lin Yu‐Shi , Kao Yi‐Hsuan 
Published: September 2010

AbstractPurpose:To investigate the correlation between the contrast‐enhanced magnetic resonance imaging (MRI) signal and the duration of blood–brain barrier (BBB) disruption induced by focused ultrasound (FUS).Materials and Methods:FUS was applied to 45 rat brains in the presence of microbubbles, and these rats were scanned on a 3T MRI system at several timepoints. The rat brains were then studied using contrast‐enhanced spin echo T1‐weighted images. At the same time, BBB disruption was evaluated based on Evans blue (EB) extravasation. The relationship between the normalized signal intensity change of the MRI and EB extravasation was analyzed by least‐squares linear regression and the calculation of correlation coefficients.Results:When MRI enhancement was quantitatively evaluated by EB extravasation, a strong correlation between the normalized signal intensity change of the MRI and EB extravasation was identified during BBB disruption after sonication. However, the correlation coefficient decreased as BBB closure occurred after sonication ended.Conclusion:The contrast‐enhanced MRI signal can potentially be used to evaluate the amount of chemotherapeutic agents entering the targeted tissue, but the accuracy of the assessment will be affected by the time interval since sonication. J. Magn. Reson. Imaging 2010;32:593–599. © 2010 Wiley‐Liss, Inc.
Decline in hepatitis B infection observed after 11 years of regional vaccination among Danish drug users
Authors: Mössner B.K. , Skamling M. , Jørgensen T. Riis , Georgsen J. , Pedersen C. , Christensen P.B. 
Published: September 2010

AbstractThe aims of this study were to determine the current prevalence of viral hepatitis and HIV among drug users, and to compare this prevalence with previous findings in the same geographical region. Cross‐sectional surveys of drug users attending treatment centers on the island of Funen with approximately 500,000 inhabitants were administered in 1996 and 2007. The 2007 prevalence estimates were: anti‐HBc 50.2%, HBsAg 0.9%, anti‐HCV 66.8%, HCV‐RNA 40%, and anti‐HIV 1.1%. The corresponding 1996 prevalence values were: anti‐HBc 70% (P < 0.0001), HBsAg 9.8% (P < 0.0001), anti‐HCV 82.8% (P < 0.0001), HCV‐RNA 56.3% (P = 0.002), and anti‐HIV 1% (P = 1). The 2007 prevalence of viral hepatitis decreased due to the increasing proportion of non‐injectors. Among injectors, the prevalence remained unchanged except for a significant decrease in HBsAg. The 2007 prevalence of ongoing HBV infection among infected (HBsAg/anti‐HBc proportion) was the lowest that to our knowledge has been reported among drug‐users. Vaccination coverage among susceptible persons tested in 2007 was 24%, compared to 0.7% in 1996. Therefore, despite an unchanged prevalence of anti‐HBc among injecting drug users, a highly significant drop in HBsAg prevalence was seen during the last decade. This observation may be linked causally to an increase in hepatitis B vaccination of the susceptible population. Our findings suggest that even incomplete vaccination, without persistent protective anti‐HBs levels, may induce an immune memory sufficient to prevent chronic infection upon transmission. J. Med. Virol. 82:1635–1639, 2010. 2010 Wiley‐Liss, Inc.
Human metapneumovirus genotypes and severity of disease in young children (n = 100) during a 7‐year study in Dijon hospital, France
Authors: Pitoiset Cécile , Darniot Magali , Huet Frédéric , Aho Serge‐Ludwig , Pothier Pierre , Manoha Catherine 
Published: September 2010

AbstractHuman metapneumovirus is a cause of respiratory tract infections at all ages. Our objectives were to analyze the distribution of the A and B genotypes over 7 years in Dijon and to investigate a possible association between hMPV genotypes and disease severity. During 2002–2009, we genotyped the 100 isolates from children <3 years old with hMPV. Phylogenetic analysis indicated a change in the distribution of hMPV genotype over the years. Severity was then measured by detailed clinical evaluation. The hospitalization rate was greater when genotype B was involved 72.5% versus 53.3% (P = 0.054). Those infected with genotype B tended to have a higher clinical score, as measured by Vicente et al. 2006 (P = 0.07). We showed that, although clinical severity is not clearly associated with hMPV genotype in this study, pathological signs on chest X‐ray were observed more often in B subgroup (P < 0.01). J. Med. Virol. 82:1782–1789, 2010. © 2010 Wiley‐Liss, Inc.
Separation optimization of quercetin, hesperetin and chrysin in honey by micellar liquid chromatography and experimental design
Authors: Hadjmohammadi Mohammad Reza , Nazari S. Saman S. J. 
Published: September 2010

AbstractThe chemometrics approach was applied for the separation optimization of flavonoid markers (quercetin, hesperetin and chrysin) in honey using micellar liquid chromatography (MLC). The investigated method combines SPE of flavonoids from honey using C18 cartridge and their separation and quantification by micellar liquid chromatography. A two level full factorial design was carried out to evaluate the effect of four experimental factors including concentration of SDS, alkyl chain length of the alcohol used as the organic modifier (N), volume percentage of the organic modifier (Vm) and volume percentage of acetic acid (AcOH) in mobile phase on analytes retention times. Experiments for analytes retention times modeling and optimization of separation were performed according to central composite design. Multiple linear regression method was used for the construction of the best model based on experimental retention times. Pareto optimal method was used to find suitable compatibility between resolution and analysis time of analytes in honey. The optimum mobile phase composition for separation and determination of analytes in honey were [SDS]=0.124 mol/L; 7.8% v/v ethanol and 5.0% v/v AcOH. Limits of detection and linear range of flavonoid markers were 0.0079–0.0126, 0.05–50.0 mg/L, respectively.
The secrets of resilient leaders
Authors: Shambaugh Rebecca 
Published: September 2010

AbstractThose who thrive show resilience, the capacity to bounce back from misfortune, disruptive change, and failures. “Whether you are at the top of your organization, leading a team, or volunteering in your community, eventually you are sure to face a difficult situation or disruptive change,” Shambaugh writes. She describes four secrets effective leaders use to tap into their own resilience and cultivate a more resilient culture within the organization.
Cerebrospinal fluid tau and phosphorylated tau protein are elevated in corticobasal syndrome
Authors: Aerts M.B. , Esselink R.A.J. , Bloem B.R. , Verbeek M.M. 
Published: September 2010

AbstractDifferentiating corticobasal syndrome (CBS) from progressive supranuclear palsy (PSP) and idiopathic Parkinson's disease (PD) can be difficult. To investigate the additional value of cerebrospinal fluid (CSF) biomarkers in the diagnostic differentiation of parkinsonism, we analyzed the CSF concentrations of total protein, lactate and brain specific proteins amyloid‐β42 protein, tau protein (t‐tau), and tau protein phosphorylated at Thr181 (p‐tau), in CSF samples from patients with PSP (n = 21), CBS (n = 12), and PD (n = 28). CBS patients demonstrated higher concentrations of t‐tau and p‐tau compared with PSP and PD patients. In discriminating CBS and PD, t‐tau offered the best combination of sensitivity (75%) and specificity (90.9%), followed by p‐tau (sensitivity 87.5% and specificity 75%). The p‐tau/t‐tau ratio resulted in sensitivity of 84.2% and specificity of 66.7% in discriminating PSP and CBS. In conclusion, our results suggest that CSF parameters are of additional value in the diagnostic differentiation of CBS and PD. © 2010 Movement Disorder Society
Entdeckungsgeschichte des Nitroglycerins. Ein Sprengstoff wird Medikament
Authors: Remane Horst , Remane Yvonne 
Published: September 2010

AbstractIm Jahre 1847 entdeckte der italienische Chemiker Ascanio Sobrero mit dem Nitroglycerin (Glyceroltrinitrat) eine Verbindung, die an Sprengkraft das herkömmliche Schwarzpulver um ein Vielfaches übertraf. Die Neigung dieser Verbindung zu spontaner Explosion war indes ein großes Hindernis für die praktische Nutzung. Mit der Fixierung des Nitroglycerins auf einem porösen Silikat gelang es dann dem Schweden Alfred Nobel dieses Hindernis zu überwinden. Als Nobels Dynamit wurde Nitroglycerin schnell zu einem gefragten Gebrauchssprengstoff. Die Erkenntnis, dass Nitroglycerin im Organismus eine Dilatation der Blutgefäße bewirkt, öffnete einer weiteren wichtigen Anwendung das Tor. Nitroglycerin wurde und wird bis heute als schnell wirksames Medikament zur Behandlung akuter Angina‐pectoris‐Anfälle eingesetzt. Mehr als 100 Jahre lang gab es über die physiologische Wirkung des Nitroglycerins nur Vermutungen. Erst in den 1970er Jahren konnte nachgewiesen werden, dass die Wirkung des Medikaments auf dem Stickstoffmonoxid (NO), einem Abbauprodukt des Nitroglycerins beruht. Dies war insofern überraschend, als man NO bis dahin hauptsächlich als Umweltgift kannte.
PDE5‐Inhibitoren in der Behandlung der pulmonalen Hypertonie. Beeinflussung des NO‐Signalweges
Authors: Dumitrescu Daniel , Erdmann Erland , Rosenkranz Stephan 
Published: September 2010

AbstractDie PDE5‐Inhibitoren, ursprünglich entwickelt für die Therapie der erektilen Dysfunktion, sind derzeit eine etablierte Therapie in der Behandlung der PAH. Zwei der drei verfügbaren Substanzen, Sildenafil und Tadalafil, sind momentan zur Therapie der PAH zugelassen. Die Wirksamkeit der PDE5‐Inhibitoren beruht auf der selektiven pulmonalen Vasodilatation durch die Hemmung des cGMP‐Abbaus in pulmonalen, glatten Gefäßmuskelzellen. Dadurch wird – vorzugsweise in gut belüfteten Lungenarealen – eine pulmonale Vasodilatation erreicht, so dass die pulmonale Hämodynamik und die Oxygenierung des pulmonal arteriellen Blutes bei gleichzeitiger Verringerung der Rechtsherzbelastung verbessert werden. Die Therapie ist gut verträglich, es gibt klassenabhängige und substanzabhängige Nebenwirkungen, die nur in seltenen Fällen schwerwiegend ausgeprägt sind. Die Wirksamkeit und Sicherheit der Substanzen konnte in großen, doppelblinden, placebo‐kontrollierten Studien nachgewiesen werden. Langzeitergebnisse und Überlebensdaten sowie die Rolle der PDE5‐Inhibitoren in der Kombinationstherapie der PAH werden derzeit in klinischen Studien untersucht.
Großangriff gegen Plasmodien
Authors: Holzgrabe Ulrike 
Published: September 2010

AbstractLaut neuesten WHO‐Berichten erkranken jährlich 2,5 Millionen Menschen an Malaria und ca. 900.000 Menschen sterben an dieser Infektion. Zumeist sind afrikanische Kinder, die südlich der Sahara leben, davon betroffen. Seit 1996 ist kein neuer Wirkstoff gegen Malaria auf den Markt gekommen und auch die Entwicklung von Impfstoffen gestaltet sich sehr schwierig. Dem stehen zunehmende Resistenzen gegen die auf dem Markt befindlichen Wirkstoffe entgegen.
Caregivers' perspectives on barriers to transcranial doppler screening in children with sickle‐cell disease
Authors: Bollinger Lindsay M. , Nire Kidan G. , Rhodes Melissa M. , Chisolm Deena J. , O'Brien Sarah H. 
Published: September 2010

AbstractBackgroundCurrent guidelines recommend that children with HbSS or HbSβ°thal undergo yearly transcranial Doppler screenings (TCD) to identify those at high risk for stroke. Compliance is low with yearly TCD screenings. Our objective was to describe caregiver experiences and knowledge of TCD screenings as well as barriers that may prevent screening.ProcedureQualitative, in‐depth interviews structured around the Health Belief Model were conducted with 36 caregivers of children eligible for annual TCD screenings. Interviews were coded and general themes were extracted.ResultsTwo‐thirds (69%) of caregivers believed that stroke occurs sometimes (33%) or frequently (36%) in children with sickle‐cell disease (SCD). Lack of knowledge was the most commonly described barrier to annual TCD screening, with 22% of caregivers reporting no knowledge of screening, and 42% unaware that the screen should be performed annually. Lack of self‐efficacy and fear of chronic transfusions were other barriers endorsed by caregivers. Barriers less commonly identified (endorsed by <10% of caregivers) included financial barriers, transportation issues, missed appointments, and hours of radiology clinic. Fifty‐eight percent of the caregivers' children with SCD had undergone a TCD in the 18 months prior to the study interview.ConclusionsFrom the caregiver perspective, lack of knowledge and low self‐efficacy play a larger role than practical barriers in compliance with annual TCDs. Ongoing education at multiple patient encounters and encouragement of caregivers' empowerment and role in obtaining annual screenings may increase TCD compliance. Pediatr Blood Cancer. 2010;56:99–102. © 2010 Wiley‐Liss, Inc.
From acyclic dialkylcarbene to the unsaturated cyclic heteroatom substituted ones: a survey of stability
Authors: Kassaee M. Z. , Ghambarian M. , Shakib F. A. , Momeni M. R. 
Published: September 2010

AbstractIn regard to the worldwide interest in synthesis and application of stable carbenes,ab initioand DFT calculations (CCSD(T)/6‐311G*//QCISD/6‐31G* and B3LYP/AUG‐cc‐pVTZ//B3LYP/6‐31 + G* levels) are employed to reach at a series of symmetrically substituted diheteroatom carbenes. In this way the multiplicity, stability, and reactivity of diethylcarbene and its saturated and unsaturated cyclic congeners are compared and contrasted to the corresponding disilyl‐, diamino‐, diphosphino‐, dioxy‐, and dithiocarbenes. The investigations reveal the enlargement of the singlet–triplet energy gaps (ΔES‐T) in the order of (amino ≈ oxy) > thio > phosphino > alkyl > silyl. The observed trend is thoroughly analyzed applying appropriate isodesmic reactions which differentiate the substituent effects on each of the singlet and triplet states of all the carbenes. In contrast to previous reports, it is found that π‐donor/σ‐acceptor amino substituents stabilize not only the singlet but also the triplet states. The effects of cyclization and unsaturation are also probed in each series of the symmetrically substituted carbenes. The reactivity of the species is discussed in terms of nucleophilicity, electrophilicity, and proton affinity. Copyright © 2010 John Wiley & Sons, Ltd.
The Kataura plot for single wall carbon nanotubes on top of crystalline quartz
Authors: Soares Jaqueline S. , Cançado Luiz G. , Barros Eduardo B. , Jorio Ado 
Published: September 2010

AbstractIn this work, we have studied the radial breathing mode (RBM) resonance Raman spectra of single‐wall carbon nanotube serpentines. Each serpentine consists of a series of straight, parallel, and regularly spaced segments, connected by alternating U‐turns formed on top of crystalline miscut quartz. We compare our ωRBM and Eii values with the results in the literature and find a strong environmental effect related to the tube–substrate interaction. We establish experimentally the ${\omega} _{{\rm RBM}} \, = \,(227/d_{{\rm t}} )\sqrt {1 + (0.082\,\pm \,0.009)d_{{\rm t}}^{2} } $ relation between RBM frequency (ωRBM) and tube diameter (dt), with a 100 ± 30 meV downshift in the optical transition energies with respect to the Eii values measured for the standard “super‐growth” samples.
Metal/semiconductor separation of single‐wall carbon nanotubes by selective adsorption and desorption for agarose gel
Authors: Tanaka Takeshi , Urabe Yasuko , Nishide Daisuke , Liu Huaping , Asano Satoshi , Nishiyama Satoko , Kataura Hiromichi 
Published: September 2010

AbstractMetallic and semiconducting single‐wall carbon nanotubes (SWCNTs) were separated by selective adsorption and desorption using agarose gel beads and SWCNTs/sodium dodecyl sulfate dispersion. Comparison to the batch method, the purities of metallic and semiconducting SWCNTs obtained by a column method were improved to 90 and 95%, respectively. When linear‐gradient elution was applied to the column method, semiconducting SWCNTs and presumed mixed bundles could be separated into early‐ and late‐eluted fractions, respectively. In the semiconducting fractions, chirality separation was also detected.
Broadened second excitonic transition of single‐walled carbon nanotubes in photoluminescence excitation spectroscopy
Authors: Heeg Sebastian , Hatting Benjamin , Dantz Marcus , Reich Stephanie 
Published: September 2010

AbstractIn this paper, we investigate how photoluminescence excitation spectra of single‐walled carbon nanotubes are influenced by experimental conditions. The use of incoherent light sources leads to a broadening of the second excitonic transition. We describe the broadening by a straight forward simulation and deliver the width of the second excitonic transition free of experimental influences. A set of simulated data allows for the correction of experimental influences for arbitrary nanotubes chiralities and excitation bandpasses.
Diameter‐selective desorption of semiconducting single‐wall carbon nanotubes from agarose gel
Authors: Liu Huaping , Tanaka Takeshi , Feng Ye , Kataura Hiromichi 
Published: September 2010

AbstractSingle‐wall carbon nanotubes (SWCNTs) were separated into metallic (M‐) and semiconducting (S‐) parts using agarose gel column chromatography method. Due to their weak interaction with agarose gel, M‐SWCNTs directly passed through the column with SDS solution while S‐SWCNTs were trapped in the gel. Then S‐SWCNTs were desorbed and eluted with sodium deoxycholate (DOC) solution from the gel. It was found that by successively increasing DOC concentration for the elution, smaller‐diameter S‐SWCNTs were firstly eluted with the lower‐concentration DOC solutions and then larger‐diameter S‐SWCNTs were eluted with the higher‐concentration DOC solutions. Thus, a kind of diameter sorting of S‐SWCNTs was achieved. We also found that the relative concentration of M‐SWCNTs in the earlier eluted smaller‐diameter S‐SWCNT fractions was much lower than that in the later eluted larger‐diameter S‐SWCNT fractions, indicating higher‐purity S‐SWCNTs can be obtained by selective fractional collection.
Semiconductors for plasmonics and metamaterials
Authors: Naik Gururaj V. , Boltasseva Alexandra 
Published: September 2010

AbstractPlasmonics has conventionally been in the realm of metal‐optics. However, conventional metals as plasmonic elements in the near‐infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals with semiconductors can alleviate these problems if only semiconductors could exhibit negative real permittivity. Aluminum doped zinc oxide (AZO) is a low loss semiconductor that can show negative real permittivity in the NIR. A comparative assessment of AZO‐based plasmonic devices such as superlens and hyperlens with their metal‐based counterparts shows that AZO‐based devices significantly outperform at a wavelength of 1.55 µm. This provides a strong stimulus in turning to semiconductor plasmonics at the telecommunication wavelengths. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fe valence state at the surface of the Fe0.5Cu0.5Cr2S4 spinel
Authors: Taubitz Christian , Hu Zhiwei , Hollmann Nils , Chin Yi‐Ying , Kuepper Karsten , Tsurkan Vladimir , Lin H.‐J. , Chen C. T. , Tjeng L. H. , Neumann Manfred 
Published: September 2010

AbstractHere we present X‐ray absorption measurements of a vacuum cleaved Fe0.5Cu0.5Cr2S4 single crystal. Measurements at different positions on the cleaved sample surface clearly reveal a difference between the valence state of the Fe ions in the sur‐ face layers and the valency of the Fe ions present in the bulk. These results confirm the findings of recent measurements outlined previously. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eine Methode der Dehydrierung von Sekundären Alkoholen zu Ketonen. I. Zur Herstellung von Sterinketonen und Sexualhormonen
Authors: Oppenauer R. V. 
Published: September 2010

AbstractEine Methode zur Bereitung von kompliziert gebauten Ketonen der Sterinreihe aus den entsprechenden Alkoholen wird beschrieben.Sie besteht darin, dass Sterinalkohole durch Ketone, z.B. Aceton, in Gegenwart von tert. Aluminium‐Alkoholaten zu den entsprechenden Ketonen dehydriert werden.Die dabei erhaltenen Ausbeuten sind ausgezeichnet, ausserdem können auf diese Weise Ketone bereitet werden, die auf anderem Wege bisher nicht zugänglich waren (Ergosta‐trienon).
Die Krystallstruktur des Ammonium‐, Kalium‐, Rubidium‐ und Cäsiumpalladiumhexa‐chlorids und ‐Bromids
Authors: Ketblaar J. A. A. , van Walsem J. F. 
Published: September 2010

AbstractDie Krystallstrukturen von K2‐, (NH4)2‐, Rb2‐ und Cs2PdCl6, und von K2, (NH4)2‐, Rb2‐ und Cs2PdBr6 gehören zum K2PtCl6‐Typus oder Jl1‐Typus. Angegeben werden Elementarabstände und Parameter.
Éthers de L'Acide Méthanetricarboxylique
Authors: Backer H. J. , Lolkema J. 
Published: September 2010

AbstractUne série d'éthers de l'acide méthanetricarboxylique a été préparée par introduction d'un troisième groupe carboxalkyle dans les éthers maloniques. Les éthers aliphatiques examinés sont liquides (l'éther décylique fond à 15°). Les éthers aromatiques, dont aucun représentant n'était connu, cristallisent aisément; on les obtient par l'intermédiaire d'un dérivé magnésien des éthers maloniques.
On the formation of higher aliphatic ketones in the thermal decomposition of fat
Authors: Holleman L. W. J. , Koolhaas D. R. 
Published: September 2010

AbstractIt is shown, that on heating fats at temperatures ranging from 200° to 350°, especially in the presence of catalysts like iron, higher aliphatic ketones are formed by the interaction of pairs of fatty acid molecules. In the case of coconut oil, one of these ketones has been isolated and proved to be the hitherto unknownn‐12‐pentacosanone.
p‐Nitrobenzazide andp‐nitrophenyl isocyanate as reagents for the identification of amines
Authors: Sah Peter P. T. 
Published: September 2010

AbstractFifty crystallinep‐nitrophenyl‐ureas have been prepared by the condensation of eitherp‐nitrobenzazide or its pyrolysis product,p‐nitrophenyl isocyanate, with various types of amines in boiling toluene solution. The yields were in general very high and the derivatives were suitable for the purpose of identification.