bluuebunny/crossref_metadata_2025 huggingface dataset:
Overall Water Splitting under Visible Light through a Two‐Step Photoexcitation between TaON and WO3 in the Presence of an Iodate–Iodide Shuttle Redox Mediator
Authors: Abe Ryu , Higashi Masanobu , Domen Kazunari
Published: January 2011

A two‐step, photocatalytic water splitting system consisting of Pt‐loaded TaON (a H2 evolution photocatalyst), Pt‐loaded WO3 (an O2 evolution photocatalyst), and an iodate–iodide (IO3−/I−) shuttle redox mediator is investigated under visible light irradiation. Photocatalytic oxidation of water to O2 and reduction of IO3− to I− proceeded with good selectivity over the Pt–WO3 photocatalyst, even in the presence of a considerable amount of I− anions in the solution. The key difference between the adsorption properties of IO3− and I− anions on WO3 strongly suggested that the photoexcited electrons could react efficiently with IO3− adsorbed on WO3, whereas the photogenerated holes selectively reacted with water molecules owing to the low adsorptivity of I− on WO3. Photocatalytic H2 evolution on Pt–TaON proceeded efficiently, accompanied by I− oxidation to IO3− due to a substantial amount of adsorption of I− anions on the surface, whereas H2 evolution was significantly inhibited by the competitive adsorption of IO3−, which consumes photoexcited electrons. It was also found that WO3 photocatalysts loaded with platinum oxide (PtO) showed a much higher activity for O2 evolution in the presence of the electron acceptor IO3−, compared to those loaded with Pt metal. Overall water splitting at a steady rate was demonstrated using a combination of Pt–TaON and Pt(PtO)–WO3 in an aqueous NaI solution with neutral or weakly acidic pH values, where the concentration of NaI significantly affected the efficiency.
Hydrothermal Decarboxylation and Hydrogenation of Fatty Acids over Pt/C
Authors: Fu Jie , Lu Xiuyang , Savage Phillip E.
Published: January 2011

We report herein on the conversion of saturated and unsaturated fatty acids to alkanes over Pt/C in high‐temperature water. The reactions were done with no added H2. The saturated fatty acids (stearic, palmitic, and lauric acid) gave the corresponding decarboxylation products (n‐alkanes) with greater than 90 % selectivity, and the formation rates were independent of the fatty acid carbon number. The unsaturated fatty acids (oleic and linoleic acid) exhibited low selectivities to the decarboxylation product. Rather, the main pathway was hydrogenation to from stearic acid, the corresponding saturated fatty acid. This compound then underwent decarboxylation to form heptadecane. On the basis of these results, it appears that this reaction system promotes in situ H2 formation. This hydrothermal decarboxylation route represents a new path for using renewable resources to make molecules with value as liquid transportation fuels.
Joint rate regulation and power control for cochannel interference limited wireless networks
Authors: Wang Jui Teng
Published: January 2011

Centralized and distributed algorithms for joint rate regulation and power control are proposed for the wireless networks where the cochannel interference limits the capacity. The goal of the proposed algorithms is maximizing the data rate while minimizing the transmitting power on each hop of the wireless networks. The distributed algorithm simulates the operation of the centralized algorithm in a distributed fashion and need not measure the link gains for all transmission links and interference links. We prove that the distributed algorithm can find the maximal transmitting rate and the minimal transmitting power as the centralized algorithm does. Simulation results also show that the proposed distributed algorithm outperforms the previous distributed algorithm in the data rate achieved. Copyright © 2011 John Wiley & Sons, Ltd.
On the design of algorithms for mobile multimedia systems: A survey
Authors: Ma Xiaoqiang , Liu Jiangchuan , Jiang Hongbo
Published: January 2011

In the past few years, we have seen a global flurry of the Internet in the rapid roll‐out of multimedia—the commercial products such as PPlive, YouTube, and Skype have occupied a large portion of Internet bandwidth. One reason behind the continual growth of multimedia services is due to the increasingly deployed and offered broadband networks. Besides the traditional wired end users, Internet service providers (ISPs) are expected to provide multimedia services, especially video streaming, to wireless end users as well in that it allows ISPs to strengthen their competitiveness by offering these new services. However, the existing solutions to multimedia in wired networks cannot directly apply to wireless networks with lower bandwidth, higher latency, and higher burst error rate. Furthermore, these services could suffer from user's mobility and the heterogeneity caused by different wireless technologies (e.g. CDMA2000, WCDMA, TD‐SCDMA, Wi‐Fi, Long‐Term Evolution (LTE), and WiMAX). This paper surveys several key issues of mobile multimedia, focusing on multirate multicast, scalable video coding (SVC), and QoS management. Besides, the opportunities as well as the challenges of providing multimedia services in the next generation wireless mobile systems—3GPP LTE—are investigated. Copyright © 2011 John Wiley & Sons, Ltd.
Mother–pup interactions during a short olfactory deprivation period in young rats
Authors: Gelhaye Mathieu , Padzys Guy Stéphane , Olry Jean‐Charles , Thornton Simon N. , Martrette Jean‐Marc , Trabalon Marie
Published: January 2011

The effects of short‐term bilateral naris occlusion (inducing olfactory deprivation) on mother–pup interactions, suckling behavior and hormonal status during post‐natal development in Wistar rats were studied. Bilateral naris occlusion was performed on 8‐day‐old rat pups and its effects were evaluated at Day 9 and at Day 15. The narins opened spontaneously between Day 12 and 14. Olfactory‐deprived pups exhibited a greater level of corticosterone at both ages versus untreated or sham animals. Olfactory deprivation via naris occlusion, in young rats, alters mother–pup interactions with a decrease in the duration of mother–pup retrieving and an increase in pup licking. Olfactory‐deprived pups showed also a lower mean duration of nursing and a decrease in nipple attachment, which appeared related to difficulties in finding the nipple. Olfactory‐deprived pups had difficulty recognizing their nest. These behavioral alterations were accompanied by a diminution in milk ingested and growth retardation associated with a reduced level of thyroxin at both 9 and 15 days of age. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 53:303–316, 2011.
An Anthracene Based Photoswitchable Dioxo‐Tetraaza Ligand Selective for CuII and Capable of Photochemical pKa Modulation
Authors: Dacarro Giacomo , Ricci Paola , Sacchi Donatella , Taglietti Angelo
Published: January 2011

Two anthracene fragments were added to a linear dioxotetramine ligand in order to exploit a [4πs+4πs] photocycloaddition reaction and obtain a photoswitchable selective receptor for CuII, whose cavity (and binding abilities) can be closed on command. Moreover, it was demonstrated that this new ligand, N,N′‐bis{2‐[(anthracen‐9‐ylmethyl)amino]ethyl}malonamide (LH2), can also be used for the photoinduced release of protons in aqueous solution, as a result of photoinduced pKa modulation.
A New Triazine‐Based Tricompartmental Ligand for Stepwise Assembly of Mononuclear, Dinuclear, and 1D‐Polymeric Heptacoordinate Manganese(II)/Azido Complexes
Authors: Das Animesh , Demeshko Serhiy , Dechert Sebastian , Meyer Franc
Published: January 2011

A new ligand 2,4,6‐tris[{N‐methyl‐N′‐(pyridine‐2‐yl)methylidene}hydrazino]‐1,3,5‐triazine (L) has been synthesized from cyanuric chloride in two steps. The threefold symmetric L features three potentially tridentate {N3} binding compartments. However, with MnII it binds a single metal ion using one of the triazine N atoms and two chelate arms. This {N5} set forms the equatorial plane of a distorted pentagonal‐bipyramidal metal ion environment, with a variety of ligands in axial positions. Five such MnII complexes have been isolated and characterized by X‐ray crystallography. Complex 1 features axial water and nitrato‐O ligands. In 5, the latter is replaced by dicyanamide. Two terminal azido ligands are found in 3. Depending on the ratio of L:MnII:azide, L may also adopt a bridging mode to give the dimeric species [{(H2O)MnIIL}(μ‐1,3‐N3){LMnII(NO3)}](NO3)2 (2) or a 1D coordination polymer [(LMnII)(μ‐1,3‐N3)]n(NO3)n (4). The basic {LMnII} entity undergoes little structural variation in the series of complexes, which can be viewed as structural snapshots for the assembly of a MnII/azido polymeric chain from well‐defined mononuclear building units. Magnetic coupling along the μ‐1,3‐azido linkage in the dimeric and 1D‐extended complexes is weakly antiferromagnetic; the strength of the coupling is rationalized on the basis of the Mn–N–N angles and the dihedral angle τ along the azide ligand.
Ring‐Closing Metathesis Approach to Heteroaromatic Cations: Synthesis of Benzo[a]quinolizinium Salts
Authors: Nuñez Ana , Abarca Beatriz , Cuadro Ana M. , Alvarez‐Builla Julio , Vaquero Juan J.
Published: January 2011

Benzo[a]quinolizinium salts have been synthesized through ring‐closing metathesis reactions of 1‐butenyl‐2‐vinylisoquinolinium, 2‐butenyl‐1‐vinylisoquinolinium and 2‐styryl‐1‐vinylpyridinium salts in the presence of Grubbs andHoveyda–Grubbs catalysts. The results show that the lastapproach is the most efficient for the preparation of this heteroaromatic tricyclic system and several previously unknown derivatives have been prepared.
Diaryl Ether Formation in the Synthesis of Natural Products
Authors: Pitsinos Emmanuel N. , Vidali Veroniki P. , Couladouros Elias A.
Published: January 2011

The structural variety of naturally occurring diaryl ethers is illustrated and the various synthetic methods employed for the construction of diaryl ether linkages in related total syntheses are reviewed. Examples of successful applications of each method (including reaction conditions, diaryl ether substitution pattern, and, when appropriate, the size of the ring formed) are given in tabular format.
A latent variable approach to forecasting the unemployment rate
Authors: Chua Chew Lian , Lim G. C. , Tsiaplias Sarantis
Published: January 2011

A forecasting model for unemployment is constructed that exploits the time series properties of unemployment while satisfying the economic relationships specified by Okun's law and the Phillips curve. In deriving the model, we jointly consider the problem of obtaining estimates of the unobserved potential rate of unemployment consistent with Okun's law and the Phillips curve, and associating the potential rate of unemployment with actual unemployment. The empirical example shows that the model clearly outperforms alternative forecasting procedures typically used to forecast unemployment. Copyright © 2011 John Wiley & Sons, Ltd.
Intergroup dialogue and democratic practice in higher education
Authors: Lopez Gretchen E. , Zúñiga Ximena
Published: January 2011

Participants in intergroup dialogue examine the significance of social identities and social inequalities and practice intergroup communication and collaboration skills.
“To establish an effective community spirit”: A Land Grant Extension and deliberative dialogue
Authors: Herrera Monica , Hoelting Joyce
Published: January 2011

The Land Grant Extension at the University of Minnesota was part of “Horizons,” a program using dialogue‐to‐action tools to address rural poverty.
Research for democracy and democracy for research
Authors: Cunningham Kiran , Leighninger Matt
Published: January 2011

Action research is a promising vehicle for filling gaps in our knowledge of deliberation and democratic governance.
Practicing what we preach: Democratic practices in institutional governance
Authors: Mallory Bruce L.
Published: January 2011

Strategies for moving closer to effective forms of shared governance, using deliberative approaches that sustain faculty authority over the academic mission.
Fibrinogen-γ proteolysis and solubility dynamics during apoptotic mouse liver injury: Heparin prevents and treats liver damage
Authors: Weerasinghe Sujith V. W. , Moons David S. , Altshuler Peter J. , Shah Yatrik M. , Omary Bishr M.
Published: January 2011

Fas ligand (FasL)-mediated hepatocyte apoptosis occurs in the context of acute liver injury that can be accompanied by intravascular coagulation (IC). We tested the hypothesis that analysis of selected protein fractions from livers undergoing apoptosis will shed light on mechanisms that are involved in liver injury that might be amenable to intervention. Proteomic analysis of the major insoluble liver proteins after FasL exposure for 4-5 hours identified fibrinogen-γ (FIB-γ) dimers and FIB-γ-containing high molecular mass complexes among the major insoluble proteins visible via Coomassie blue staining. Presence of the FIB-γ-containing products was confirmed using FIB-γ-specific antibodies. The FIB-γ-containing products partition selectively and quantitatively into the liver parenchyma after inducing apoptosis. Similar formation of FIB-γ products occurs after acetaminophen administration. The observed intrahepatic IC raised the possibility that heparin therapy may ameliorate FasL-mediated liver injury. Notably, heparin administration in mice 4 hours before or up to 2 hours after FasL injection resulted in a dramatic reduction of liver injury—including liver hemorrhage, serum alanine aminotransferase, caspase activation, and liver apoptosis—compared with heparin-untreated mice. Heparin did not directly interfere with FasL-induced apoptosis in isolated hepatocytes, and heparin-treated mice survived the FasL-induced liver injury longer compared with heparin-untreated animals. There was a sharp, near-simultaneous rise in FasL-induced intrahepatic apoptosis and coagulation, with IC remaining stable while apoptosis continued to increase.

Conclusion:

Formation of FIB-γ dimers and their high molecular mass products are readily detectable within the liver during mouse apoptotic liver injury. Heparin provides a potential therapeutic modality, because it not only prevents extensive FasL-related liver injury but also limits the extent of injury if given at early stages of injury exposure. (HEPATOLOGY 2011;)
Lineage tracing demonstrates no evidence of cholangiocyte epithelial-to-mesenchymal transition in murine models of hepatic fibrosis
Authors: Chu Andrew S. , Diaz Rosalyn , Hui Jia-Ji , Yanger Kilangsungla , Zong Yiwei , Alpini Gianfranco , Stanger Ben Z. , Wells Rebecca G.
Published: January 2011

Whether or not cholangiocytes or their hepatic progenitors undergo an epithelial-to-mesenchymal transition (EMT) to become matrix-producing myofibroblasts during biliary fibrosis is a significant ongoing controversy. To assess whether EMT is active during biliary fibrosis, we used Alfp-Cre × Rosa26-YFP mice, in which the epithelial cells of the liver (hepatocytes, cholangiocytes, and their bipotential progenitors) are heritably labeled at high efficiency with yellow fluorescent protein (YFP). Primary cholangiocytes isolated from our reporter strain were able to undergo EMT

in vitro

when treated with transforming growth factor-β1 alone or in combination with tumor necrosis factor-α, as indicated by adoption of fibroblastoid morphology, intracellular relocalization of E-cadherin, and expression of α-smooth muscle actin (α-SMA). To determine whether EMT occurs

in vivo

, we induced liver fibrosis in Alfp-Cre × Rosa26-YFP mice using the bile duct ligation (BDL) (2, 4, and 8 weeks), carbon tetrachloride (CCl4) (3 weeks), and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC; 2 and 3 weeks) models. In no case did we find evidence of colocalization of YFP with the mesenchymal markers S100A4, vimentin, α-SMA, or procollagen 1α2, although these proteins were abundant in the peribiliary regions.

Conclusion:

Hepatocytes and cholangiocytes do not undergo EMT in murine models of hepatic fibrosis. (Hepatology 2011;)
Notch1 differentially regulates oncogenesis by wildtype p53 overexpression and p53 mutation in grade III hepatocellular carcinoma
Authors: Lim Seung-Oe , Park Young Min , Kim Hyeon Seop , Quan Xiaoyuan , Yoo Jeong Eun , Park Young Nyun , Choi Gi Hong , Jung Guhung
Published: January 2011

The tumor suppressor p53 is a key prognostic factor in hepatocellular carcinoma (HCC), yet only 35% of grade III tumors exhibit mutation of p53. Several other pathways have been implicated in HCC and, among these, the role of the Notch1/Snail pathway remains unclear. Therefore, we investigated the expression of p53, Notch1, and Snail proteins in HCC with regard to both clinical grade and p53 mutational status. Immunoblotting for p53 revealed that, whereas in many tumors increased p53 was a result of p53 mutation, wildtype p53 (p53WT) expression was also frequently elevated in HCCs. Coordinated evaluation of p53, Notch1, and Snail expression suggests that grade III HCC can be subdivided based on the expression of these three proteins. We found that Notch1 expression in HCC tissues and cell lines is differentially affected by p53WT and mutant p53 (p53Mut). Notch1 expression was correlated with p53 expression in cells expressing p53WT, but was not elevated in p53Mut-expressing cells. Virally mediated expression or silencing of p53WT or p53Mut confirmed that p53WT overexpression causes Notch1 up-regulation in HCC. Surprisingly, the consequence of Notch1 overexpression for the proliferative and invasive capacity of HCC cells depends on both the p53 mutational status and activation of the Snail pathway.

Conclusion:

In the presence of p53WT, Snail/Notch1 activation increased the invasiveness of HCC cells. In contrast, in the absence of p53WT, Notch1 decreased the invasiveness of HCC. Taken together, these findings shed new light on the complex role of the Notch1/Snail axis in HCC and provide a framework for further classifying HCC based on the expression and mutational status of p53 and the expression of Notch1 and Snail. (HEPATOLOGY 2011;53:1352-1362)
Assessing human resource practices alignment: A case study
Authors: Heneman Herbert G. , Milanowski Anthony T.
Published: January 2011

Research has established the link between HR practices and organizational performance, suggesting that the HR system has great strategic potential to drive organizational effectiveness. To capitalize on this potential, the organization must design and deliver HR practices that focus on necessary employee performance competencies, creating an HR system with vertical and horizontal alignment around those competencies. Doing this requires that the organization first assess how its HR practices are currently aligned and then develop ideas for improving HR practice that will be alignment enhancing. We call this diagnostic process Human Resource Alignment (HRA) assessment. We describe an HRA assessment process we developed and applied in a large public school district for the key job of teacher. The assessment was based on the district's formal teacher performance competency model used, and was conducted by a group of human resources and instructional job experts from the district. These experts rated the degree of vertical and horizontal alignment and then developed suggestions for HR practice changes that would improve alignment. After describing the process and results, we present a series of lessons learned and directions for future research. © 2011 Wiley Periodicals, Inc.
Tracing a confined groundwater flow system under the pressure of excessive groundwater use in the lower central plain, Thailand
Authors: Yamanaka Tsutomu , Shimada Jun , Tsujimura Maki , Lorphensri Oranuj , Mikita Makoto , Hagihara Atsushi , Onodera Shinichi
Published: January 2011

Excessive groundwater pumping from deep wells in the Bangkok metropolitan area (BMA) since the 1950s has induced piezometric drawdown, land subsidence, and probably remarkable disturbance in confined groundwater flow. To trace the large‐scale groundwater flow system in the Lower Central Plain (LCP) of Thailand and to detect its disturbance, we carried out isotopic and hydro‐chemical investigations of surface/subsurface waters as well as hydrometric measurements at 98 observation wells. Isotopic compositions of the water (δD and δ18O) reflected significant seawater mixing and evaporative enrichment. The Cl/Br mass ratio suggested that halite dissolution is negligible, and spatial distributions of δ and Cl− concentration implied that saline water is mainly remnant seawater. In addition, the δ–Cl relationship indicated that the remnant seawater may have been concentrated in part by transpiration from mangrove forests during delta formation after a period of maximum transgression. The original δD of the source water was estimated by correcting for the effects of seawater mixing and evaporative enrichment using the Cl− concentration and δ18O, respectively, and its three‐dimensional distribution revealed that the water originating from precipitation over the LCP during the post‐glacial age was drawn down to a maximum depth of 240 m by groundwater pumping. At two large depressions in the east and west of the BMA, water recharged during the last glacial age and/or originating at higher elevations outside the LCP is drawn from suburban areas laterally or through underlying aquifers. In contrast, in the central BMA, groundwater within major productive aquifers is mainly replenished by downward leakage across confining layers. Copyright © 2011 John Wiley & Sons, Ltd.
Simulation of complicated and diverse water system accompanied by human intervention in the North China Plain
Authors: Nakayama Tadanobu
Published: January 2011

The author simulated water/heat dynamics in the North China plain (NCP) by coupling the NIES Integrated Catchment‐based Eco‐hydrology (NICE) model series with dam/canal systems in the agricultural and urban areas (NICE‐CNL). This combined model was applied to the Hai River catchment and the lower reach of the Yellow River (530 km wide × 840 km long) at a resolution of 5 km. It satisfactorily reproduced river discharge, soil moisture, evapotranspiration, groundwater level, and crop production of summer maize and winter wheat, correctly estimating—without any detailed statistical data—the amount of crop water use. The simulation showed that irrigation and industrial use of groundwater has a marked effect on the water dynamics in the NCP because the river water volume is smaller than that necessary for irrigation, industrial and, domestic water use. The model reproduced, reasonably well, the trend of groundwater degradation over the previous half century, including cone depressions occurring around bigger cities, which the author was unable to reproduce in previous research. The simulation also clarified that this water shortage is related to the low flow discharge of the Hai River into the ocean. Furthermore, the simulated result for the density current and solute transport processes clarified that these water cycle changes have caused serious seawater intrusion and a decrease of crop productivity in the coastal area, as shown by the gradient of NDVI (Normalized Difference Vegetation Index) estimated from satellite images. This study has important implications for the evaluation of ecosystems and environments located on the moving edge of freshwater and marine areas. Copyright © 2011 John Wiley & Sons, Ltd.
The Electoral Success of Beauties and Beasts
Authors: Lutz Georg
Published: January 2011

Les prises de positions, les programmes politiques ou encore les résultats précédents des candidats et des partis n'expliquent que partiellement leur succès électoral. D'autres mécanismes, plus simples, jouent aussi un rôle. Dans cet article, nous explorons l'influence de l'attractivité physique sur le nombre de votes de préférence reçus par 744 candidats à l’élection au Conseil national en Suisse en 2007. Le système électoral suisse de scrutin proportionnel avec liste ouverte offre une excellente opportunité d’étudier de tels effets, car les électeurs ne choisissent pas simplement entre partis ou entre candidats, mais également entre candidats au sein du même parti. Nous démontrons un effet robuste de l'attractivité physique sur le nombre de votes de préférence reçus par un candidat. L'effet est aussi important pour les femmes que pour les hommes. Cette influence de l'attractivité est essentiellement liée au fait que les candidats attractifs ont une plus grande probabilité d’être remarqués.
Strategic Overshooting in National Council Elections
Authors: Lachat Romain , Selb Peter
Published: January 2011

The Swiss party system has become strongly polarized over the last decade, following the rise of the Swiss People's Party and the electoral losses of center parties. This article suggests that these developments are, at least in part, a consequence of strategic behaviour among voters. As the government policy is the result of institutionalized multiparty bargaining, voters have incentives to compensate for this watering‐down by supporting parties whose positions are more extreme than their own. This article empirically tests extent and conditions of compensatory voting in the 2007 National Council Elections using Selects survey data. Our results suggest that compensatory voting generally outweighs voting based on ideological proximity and increases with rising district magnitude.
Pre‐Election Positions and Voting Behaviour in Parliament: Consistency among Swiss MPs
Authors: Schwarz Daniel , Schädel Lisa , Ladner Andreas
Published: January 2011

This article examines the determinants of positional incongruence between pre‐election statements and post‐election behaviour in the Swiss parliament between 2003 and 2009. The question is examined at the individual MP level, which is appropriate for dispersion‐of‐powers systems like Switzerland. While the overall rate of political congruence reaches about 85%, a multilevel logit analysis detects the underlying factors which push or curb a candidate's propensity to change his or her mind once elected. The results show that positional changes are more likely when (1) MPs are freshmen, (2) individual voting behaviour is invisible to the public, (3) the electoral district magnitude is not small, (4) the vote is not about a party's core issue, (5) the MP belongs to a party which is located in the political centre, and (6) if the pre‐election statement dissents from the majority position of the legislative party group. Of these factors, the last one is paramount.
Die Fachhochschulen in der Schweiz: Pfadabhängigkeit und Profilbildung
Authors: Weber Karl , Tremel Patricia , Andreas Balthasar
Published: January 2011

Der Aufbau der Fachhochschulen zu Beginn der 1990er Jahre fand in einem unschweizerisch rasanten Tempo statt und führte zu einer Differenzierung und wachsenden Vielfalt im Schweizer Hochschulwesen. Der Beitrag geht erstens der Frage nach, wie sich im Planungsprozess das hochschulpolitische Feld ausdifferenziert hat, welche Akteure sich positioniert haben, welches ihre Leitvorstellungen sind und wie sie zusammenwirken. Anhand von empirischen Daten kann zweitens gezeigt werden, welches Profil der Fachhochschulen unter diesen Voraussetzungen entstehen konnte. Dieses wird datenbasiert für das Lehrpersonal, die Studierenden und die Forschung dokumentiert. Im Kern werden damit Fragen der vertikalen Strukturierung des tertiären Bildungssystems und der Positionierung der Ausbildung hochqualifizierter Arbeitskräfte thematisiert. Zwei sich ergänzende theoretische Perspektiven helfen, die Befunde in einen systematischen Zusammenhang zu stellen und zu interpretieren.
T2 preparation method for measuring hyperemic myocardial O2 consumption: in vivo validation by positron emission tomography
Authors: McCommis Kyle S. , O'Connor Robert , Abendschein Dana R. , Muccigrosso David , Gropler Robert J. , Zheng Jie
Published: January 2011

Purpose

To validate a new T2‐prepared method for the quantification of regional myocardial O2 consumption during pharmacologic stress with positron emission tomography (PET).

Materials and Methods

A T2 prepared gradient‐echo sequence was modified to measure myocardial T2 within a single breath‐hold. Six beagle dogs were randomly selected for the induction of coronary artery stenosis. Magnetic resonance imaging (MRI) experiments were performed with the T2 imaging and first‐pass perfusion imaging at rest and during either dobutamine‐ or dipyridamole‐induced hyperemia. Myocardial blood flow (MBF) was quantified using a previously developed model‐free algorithm. Hyperemic myocardial O2 extraction fraction (OEF) and consumption (MVO2) were calculated using a two‐compartment model developed previously. PET imaging using 11C‐acetate and 15O‐water was performed in the same day to validate OEF, MBF, and MVO2 measurements.

Results

The T2‐prepared mapping sequence measured regional myocardial T2 with a repeatability of 2.3%. By myocardial segment‐basis analysis, MBF measured by MRI is closely correlated with that measured by PET (R2 = 0.85, n = 22). Similar correlation coefficients were observed for hyperemic OEF (R2 = 0.90, n = 9, mean difference of PET – MRI = −2.4%) and MVO2 (R2 = 0.83, n = 7, mean difference = 4.2%).

Conclusion

The T2‐prepared imaging method may allow quantitative estimation of regional myocardial oxygenation with relatively good accuracy. The precision of the method remains to be improved. J. Magn. Reson. Imaging 2011;33:320–327. © 2011 Wiley‐Liss, Inc.
Dynamic contrast‐enhanced MRI of primary rectal cancer: Quantitative correlation with positron emission tomography/computed tomography
Authors: Gu Jing , Khong Pek‐Lan , Wang Silun , Chan Queenie , Wu Ed X. , Law Wailun , Liu Rico Kingyin , Zhang Jingbo
Published: January 2011

Purpose

To assess the correlations between parameters measured on dynamic contrast‐enhanced magnetic resonance imaging and 18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) in rectal cancer.

Materials and Methods

To assess the correlations between parameters measured on dynamic contrast‐enhanced MRI and FDG‐PET in rectal cancer.

Results

Significant correlations were only demonstrated between kepand SUVmax (r = 0.587,P= 0.001), and kepand SUVmean (r = 0.562,P= 0.002). No significant differences were found in imaging parameters between well, moderately and poorly differentiated adenocarcinoma groups. However, there was a trend that higher imaging values were found in poorly differentiated adenocarcinomas.

Conclusion

Positive correlations were found between kepand SUV values in primary rectal adenocarcinomas suggesting an association between angiogenesis and metabolic activity and further reflecting that angiogenic activity in washout phase is better associated with tumor metabolism than the uptake phase. J. Magn. Reson. Imaging 2011;33:340–347. © 2011 Wiley‐Liss, Inc.
Interstitial MR lymphography in mice with gadopentetate dimeglumine and gadoxetate disodium
Authors: Sheng Fugeng , Inoue Yusuke , Kiryu Shigeru , Watanabe Makoto , Ohtomo Kuni
Published: January 2011

Purpose

To investigate the utility of interstitial MR lymphography with gadopentetate dimeglumine (Gd‐DTPA) or gadoxetate disodium (Gd‐EOB‐DTPA) in mice.

Materials and Methods

We performed MR lymphography after the subcutaneous injection of Gd‐DTPA or Gd‐EOB‐DTPA (0.1, 0.5, or 2.0 μmol per mouse) into the right footpad in six healthy mice, and the time courses of contrast enhancement were assessed. Additionally, the lymphatic pathways from two distinct sites were assessed in tandem by interstitial MR lymphography studies.

Results

Subcutaneous injection of Gd‐DTPA or Gd‐EOB‐DTPA caused lymph node enhancement immediately after injection, followed by a rapid decline. Dose dependency was shown for the lymph node enhancement, and a high‐dose injection caused prominent visualization of the veins. Lymph node enhancement did not differ significantly between Gd‐DTPA and Gd‐EOB‐DTPA or between Gd‐EOB‐DTPA premixed and not premixed with bovine serum albumin. The tandem assessment of two lymphatic pathways was feasible, and image fusion aided detailed comparison.

Conclusion

Interstitial MR lymphography with Gd‐DTPA or Gd‐EOB‐DTPA allowed clear visualization of the lymphatic pathway in healthy mice, and no significant difference was found between the two agents. Their rapid kinetics limits the imaging timing window, however, facilitates repeated assessment in a single imaging session. J. Magn. Reson. Imaging 2011;33:490–497. © 2011 Wiley‐Liss, Inc.
Measuring bone erosion and edema in rheumatoid arthritis: A comparison of manual segmentation and RAMRIS methods
Authors: Crowley Angela R. , Dong Jing , McHaffie Alex , Clarke Andrew W. , Reeves Quentin , Williams Megan , Robinson Elizabeth , Dalbeth Nicola , McQueen Fiona M.
Published: January 2011

Purpose

To investigate the reliability, feasibility, and validity of a computer‐assisted manual segmentation (outlining) technique for measuring magnetic resonance imaging (MRI) bone erosion and edema at the wrist in rheumatoid arthritis (RA).

Materials and Methods

The 3T MRI scans were obtained in 22 RA patients (<2 years). Bone erosion and edema volumes were scored by two readers using outlining and were compared with RAMRIS scores.

Results

Using outlining, intraobserver reliability for erosions and edema was high: intraclass correlation coefficients (ICCs) = 0.994 (0.991, 0.997) and 0.996 (0.994, 0.998), respectively (Reader 1). Interobserver reliability was high for bone erosion (ICC [90% confidence interval, CI] = 0.80 [0.64, 0.92]) and comparable to RAMRIS scoring (ICC 0.78 [0.64, 0.92]), but was only moderate for bone edema (0.46 [0.00, 0.96]), compared with RAMRIS (ICC = 0.84 [0.73, 0.94]). The methods were highly correlated for erosion scores, r = 0.90, 0.82 (Readers 1 and 2) and moderately correlated for edema, r = 0.57, 0.87.

Conclusion

Segmentation (outlining) can be used to measure the volume of MRI bone erosion and edema at the wrist in RA patients. When compared with RAMRIS scoring, outlining had similar reliability for quantifying erosions but reliability was lower for bone edema, possibly reflecting difficulty delineating the borders of affected bone. J. Magn. Reson. Imaging 2011;33:364–371. © 2011 Wiley‐Liss, Inc.
Cardiovascular magnetic resonance imaging for accurate sizing of the left atrium: Predictability of pulmonary vein isolation success in patients with atrial fibrillation
Authors: Jahnke Cosima , Fischer Julia , Mirelis Jesus Gonzalez , Kriatselis Charalampos , Gerds‐Li Jin‐Hong , Gebker Rolf , Manka Robert , Schnackenburg Bernhard , Fleck Eckart , Paetsch Ingo
Published: January 2011

Purpose

To prospectively determine the most reproducible approach for left‐atrial size assessment using cardiovascular magnetic resonance (CMR) imaging in patients with atrial fibrillation and its value for prediction of pulmonary vein isolation (PVI) treatment success.

Materials and Methods

Eighty patients underwent CMR imaging prior to PVI; the CMR examination included standard cine sequences, a multislice cine sequence in 4‐chamber orientation with full left‐atrial coverage, and a contrast‐enhanced MR angiography of the left atrium. Left‐atrial size was determined as: diameter, area, volume segmented from angiography, and diastolic/systolic volumes from cine imaging (Simpson's rule). All measurements were carried out by two independent observers and repeated by one observer to assess inter‐ and intrareader variability. Treatment success was defined as persisting sinus rhythm after PVI (follow‐up period 12.6 ± 6.6 months).

Results

All left‐atrial measurements showed substantial intrareader agreement. Interreader agreement was substantial for diastolic/systolic left‐atrial volumes only. Calculated bias was found to be minimal (0.1%–4.9%). Predictability of PVI treatment success was best using cine volumetric measurements (cutoff value for diastolic volume, 112 mL) yielding a sensitivity and specificity of 80% and 70%, respectively.

Conclusion

Left‐atrial volumetry based on cine imaging represented the most reproducible approach to determine left‐atrial size. PVI success was predicted best using cine volumetry. J. Magn. Reson. Imaging 2011;33:455–463. © 2011 Wiley‐Liss, Inc.
Cardiovascular MRI for the assessment of heart failure: Focus on clinical management and prognosis
Authors: Muzzarelli Stefano , Ordovas Karen , Higgins Charles B.
Published: January 2011

Cardiovascular MR (CMR) has an emerging role in the noninvasive diagnostic assessment of heart failure (HF). Different imaging sequences allow for a detailed assessment of cardiac morphology, function, myocardial perfusion, tissue characterization, and blood flow measurement. This article reviews the key applications of CMR in HF, with special focus on how CMR may influence the diagnostic and therapeutic approach of HF patients. J. Magn. Reson. Imaging 2011;33:275–286. © 2011 Wiley‐Liss, Inc.
Whole‐brain cerebral blood flow mapping using 3D echo planar imaging and pulsed arterial tagging
Authors: Gai Neville D. , Talagala S. Lalith , Butman John A.
Published: January 2011

Purpose

To quantitate cerebral blood flow (CBF) in the entire brain using the 3D echo planar imaging (EPI) PULSAR (pulsed star labeling) technique.

Materials and Methods

The PULSAR technique was modified to 1) incorporate a nonselective inversion pulse to suppress background signal; 2) to use 3D EPI acquisition; and 3) to modulate flip angle in such a manner as to minimize the blurring resulting from T1 modulation along the slice encoding direction. Computation of CBF was performed using the general kinetic model (GKM). In a series of healthy volunteers (n = 12), we first investigated the effects of introducing an inversion pulse on the measured value of CBF and on the temporal stability of the perfusion signal. Next we investigated the effect of flip angle modulation on the spatial blurring of the perfusion signal. Finally, we evaluated the repeatability of the CBF measurements, including the influence of the measurement of arterial blood magnetization (a calibration factor for the GKM).

Results

The sequence provides sufficient perfusion signal to achieve whole brain coverage in ≈5 minutes. Introduction of the inversion pulse for background suppression did not significantly affect computed CBF values, but did reduce the fluctuation in the perfusion signal. Flip angle modulation reduced blurring, resulting in higher estimates of gray matter (GM) CBF and lower estimates of white matter (WM) CBF. The repeatability study showed that measurement of arterial blood signal did not result in significantly higher error in the perfusion measurement.

Conclusion

Improvements in acquisition and sequence preparation presented here allow for better quantification and localization of perfusion signal, allowing for accurate whole‐brain CBF measurements in 5 minutes. J. Magn. Reson. Imaging 2011;33:287–295. © 2011 Wiley‐Liss, Inc.
Optimized density‐weighted imaging for dynamic contrast‐enhanced 3D‐MR mammography
Authors: Gutberlet Marcel , Roth Anne , Hahn Dietbert , Köstler Herbert
Published: January 2011

Purpose

To increase the spatial coverage and to reduce slice crosstalk combined with an optimal signal‐to‐noise ratio (SNR) in 3D dynamic contrast‐enhanced (DCE) magnetic resonance (MR) mammography.

Materials and Methods

Asymmetric sampling schemes and a new reconstruction strategy based on virtual coils are presented for density‐weighted (DW) 3D imaging. Additionally, for MR mammography an alternating DW (ADW) sampling along the ky direction shifts the undersampling artifacts out of the signal reception region. Virtual coils for effective DW (VIDED) imaging suppresses the aliasing in undersampled DW imaging. VIDED and ADW were compared to the conventional Cartesian imaging in phantom and in vivo MR mammography studies.

Results

The slice crosstalk was significantly reduced by VIDED and compared to Cartesian imaging the SNR increased by 16%. Additionally, VIDED and ADW provided a substantially increased field of view (FOV) in the slice direction and allowed the spatial resolution to be improved (up to 60% for ADW and 30% for VIDED) without lengthening the scan time.

Conclusion

VIDED and ADW improve the image quality in 3D DCE MR mammography by enhancing the spatial resolution, reducing the slice crosstalk at nearly optimal SNR, and increasing the FOV in the slice direction. For VIDED no lengthening of the scan time or usage of multichannel receiver coils is necessary. J. Magn. Reson. Imaging 2011;33:328–339. © 2011 Wiley‐Liss, Inc.
Degenerative endplate changes of the lumbosacral spine: Dynamic contrast‐enhanced MRI profiles related to age, sex, and spinal level
Authors: Savvopoulou Vasiliki , Maris Thomas G. , Koureas Andreas , Gouliamos Athanasios , Moulopoulos Lia A.
Published: January 2011

Purpose

To investigate differences in perfusion profiles between degenerative endplate marrow changes and normal vertebral marrow in relation to spinal level, age, and sex with dynamic contrast‐enhanced magnetic resonance imaging (DCE MRI).

Materials and Methods

Ninety‐two consecutive patients referred for evaluation of low back pain or sciatica, without history of malignant or chronic disease, underwent conventional and DCE MRI of the lumbosacral spine. Fifty‐two of them demonstrated degenerative endplate marrow changes. Regions of interest were placed on sites of normal marrow (group A) and degenerative changes (group B) on subtracted images. Fitted time‐intensity curves (fTICs) were generated and evaluated for curve pattern. Both groups were stratified into upper (L1‐L2) and lower (L3‐I1) levels, males and females younger or older than 50 years. Perfusion parameters were calculated and statistically compared for both groups and subgroups. Receiver operator curve (ROC) analysis was also performed.

Results

Two fTIC patterns were identified. Perfusion parameters of degenerative changes and normal marrow differed significantly, even when groups were stratified for spinal level, age, and sex (P < 0.05). A time to peak value >108 seconds was characteristic for degenerative changes with sensitivity 69.5% and specificity 84.6%.

Conclusion

DCE MRI profiles of degenerative endplate marrow changes of the lumbosacral spine differ significantly from normal marrow regardless of spinal level, age, or sex. J. Magn. Reson. Imaging 2011;33:382–389. © 2011 Wiley‐Liss, Inc.
Prostate T1 quantification using a magnetization‐prepared spiral technique
Authors: Foltz Warren D. , Haider Masoom A. , Chung Peter , Bayley Andrew , Catton Charles , Ramanan Venkat , Jaffray David , Wright Graham A. , Ménard Cynthia
Published: January 2011

Purpose

To adapt a magnetization‐prepared spiral imaging technique, termed T1prep, for time‐efficient radiofrequency (RF)‐insensitive prostate T1 quantification at 1.5 T and evaluate signal‐to‐noise ratio (SNR) limits to voxel‐based versus subregion analysis.

Materials and Methods

A magnetization‐prepared spiral imaging technique was adapted for robust T1 contrast development, multislice imaging within 5 minutes, and data regression to a monoexponential decay. In vitro testing evaluated RF insensitivity of the multislice acquisition plus method accuracy. A pilot study was performed in 15 patients with low or intermediate risk localized prostate cancer.

Results

The multislice design displayed excellent RF insensitivity (<1% error for RF mistunings to ± 20%) and accuracy (within 3% of gold standard for T1 values between 140 and 2100 msec). A clinical pilot study reported significantly reduced T1 from PZ to CG to tumor subregions (PZ: 1421 ± 168 msec, n = 11; CG: 1314 ± 49 msec, n = 13; 1246 ± 68 msec, n = 8). SNR measurements identified an inappropriateness of voxel‐based analysis.

Conclusion

T1prep can quantify prostate T1 as an adjunct measure for quantitative perfusion measurements and longitudinal treatment response monitoring. Intrapatient heterogeneities support T1 assessment within individual patients. SNR calculations will support a transition to voxel‐based analysis in future trials. J. Magn. Reson. Imaging 2011. © 2011 Wiley‐Liss, Inc.
Correction of left ventricular wall thickening from short‐axis cine MRI for basal‐descent through‐plane motion
Authors: Chai Jyh‐Wen , Chen Wei‐Hsun , Chen Hsian‐Min , Chiang Chih‐Ming , Huang Jin‐Long , Fu Jachih , Chi‐Chang Chen Clayton , Lee San‐Kan
Published: January 2011

Purpose

To solve the problem of the basal descent movement in quantification of the regional left ventricular (LV) myocardial wall thickness (WTh) and wall thickening (%WT) in short‐axis (SA) cine MRI for effectively assessing the regional wall motion of LV myocardium.

Materials and Methods

LV long‐axis tagged MRI and SA cine MRI were performed to calculate the longitudinal translation and circumferential WTh of LV myocardium in eight normal volunteers. The new SA end‐systolic thickness (EST) data were reconstructed from the original EST data, based on the quantified longitudinal translation of LV myocardium.

Results

The mean %WT of six segments in the basal section after correction was significantly different from that before correction in both intra‐ and inter‐operator experiments. The polar map also showed the significant improvement of the variability of regional %WT and lack of quantification of %WT in the most basal SA slices after correction.

Conclusion

The proposed technique demonstrated an important advantage to calculate the %WT in the most basal SA myocardial tissue, which was considered difficult to be achieved using cine MRI. J. Magn. Reson. Imaging 2011;33:464–473. © 2011 Wiley‐Liss, Inc.
Why hire a former military person for a leadership position?
Authors: Price Daniel R.
Published: January 2011

Where can an organization go to find highly qualified leaders? Is there a source of world‐class, trained leaders with experience in rapidly changing situations, teamwork, and problem solving? A recent insightful article in Fortune (O'Keefe, 2010) provides the answer: the U.S. military. Companies such as Walmart, Home Depot, Lowe's, State Farm, AT&T, Bank of America, Merck, GE, Northrop Grumman, PepsiCo, and others are hiring what the Fortune article calls the “elite” from the military ranks.
Opting in: The experiences, pathways, and meaning of successful, professional, generation X women making intentional career transitions
Authors: Anding Julie
Published: January 2011

This qualitative study explores eight upwardly mobile, professional Generation X women who took an introspective approach to making a career transition. Irving Seidman's phenomenological‐based approach to in‐depth interviewing was used to examine the internal, subjective experiences of intentional career transitions and the experience of meaning making. Each participant's story revealed aspects of an inward journey resulting in a recommitment to work that allowed an integration of the participant's needs for achievement, challenge, and continued learning with more meaning and authenticity.
Bactericidal Block Copolymer Micelles
Authors: Vyhnalkova Renata , Eisenberg Adi , van de Ven Theo
Published: January 2011

Block copolymer micelles with bactericidal properties were designed to deactivate pathogens such as E. coli bacteria. The micelles of PS‐b‐PAA and PS‐b‐P4VP block copolymers were loaded with biocides TCMTB or TCN up to 20 or 30 wt.‐%, depending on the type of antibacterial agent. Bacteria were exposed to loaded micelles and bacterial deactivation was evaluated. The micelles loaded with TCN are bactericidal; bacteria are killed in less than two minutes of exposure. The most likely interpretation of the data is that the biocide is transferred to the bacteria by repeated micelle/bacteria contacts, and not via the solution.

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