bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic method for the development of a three‐phase transformer non‐linear model
Authors: Theocharis Andreas D. , Milias‐Argitis John , Zacharias Thomas
Published: May 2009

In this work, a novel three‐phase transformer non‐linear model is developed. The proposed model takes into account the magnetic core topology and the windings connections. The non‐linear characteristic curve of the core material is introduced by its magnetization curve or by its hysteresis loop using the mathematical hysteresis model proposed by Tellinen or the macroscopic hysteresis model proposed by Jiles–Atherton. The eddy currents effects are included through non‐linear resistors using Bertotti's work. The proposed model presents several advantages. An incremental linear circuit, having the same topology with the magnetic circuit of the core, is used in order to directly write the differential equations of the magnetic part of the transformer. The matrix Ld that describes the coupling between the windings of the transformer is systematically derived. The electrical equations of the transformer can be easily written for any possible connection of the primary and secondary windings using the unconnected windings equations and transformation matrices. The proposed methods for the calculation of the coupling between the windings, the representation of the eddy currents and the inclusion of the core material characteristic curve can be used to develop a transformer model appropriate for the EMTP/ATP‐type programs. Copyright © 2009 John Wiley & Sons, Ltd.
A critical step for postsynaptic F‐actin organization: Regulation of Baz/Par‐3 localization by aPKC and PTEN
Authors: Ramachandran Preethi , Barria Romina , Ashley James , Budnik Vivian
Published: May 2009

Actin remodeling has emerged as a critical process during synapse development and plasticity. Thus, understanding the regulatory mechanisms controlling actin organization at synapses is exceedingly important. Here, we used the highly plastic Drosophila neuromuscular junction (NMJ) to understand mechanisms of actin remodeling at postsynaptic sites. Previous studies have suggested that the actin‐binding proteins Spectrin and Coracle play a critical role in NMJ development and the anchoring of glutamate receptors most likely through actin regulation. Here, we show that an additional determinant of actin organization at the postsynaptic region is the PDZ protein Baz/Par‐3. Decreasing Baz levels in postsynaptic muscles has dramatic consequences for the size of F‐actin and spectrin domains at the postsynaptic region. In turn, proper localization of Baz at this site depends on both phosphorylation and dephosphorylation events. Baz phosphorylation by its binding partner, atypical protein kinase C (aPKC), is required for normal Baz targeting to the postsynaptic region. However, the retention of Baz at this site depends on its dephosphorylation mediated by the lipid and protein phosphatase PTEN. Misregulation of the phosphorylation state of Baz by genetic alterations in PTEN or aPKC activity has detrimental consequences for postsynaptic F‐actin and spectrin localization, synaptic growth, and receptor localization. Our results provide a novel mechanism of postsynaptic actin regulation through Baz, governed by the antagonistic actions of aPKC and PTEN. Given the conservation of these proteins from worms to mammals, these results are likely to provide new insight into actin organization pathways. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009
Maternal care effects on SNB motoneuron development: The mediating role of sensory afferent distribution and activity
Authors: Lenz Kathryn M. , Sengelaub Dale R.
Published: May 2009

Maternal licking in rats affects the development of the spinal nucleus of the bulbocavernosus (SNB), a sexually dimorphic motor nucleus that controls penile reflexes involved with copulation. Reduced maternal licking produces decreased motoneuron number, size, and dendritic length in the rostral portion of the adult SNB as well as deficits in adult male copulatory behavior. Previous research suggests that decreases in perineal tactile stimulation may be responsible for these effects. To determine whether the regional effects of maternal licking on SNB morphology are driven by sensory afferent innervation of the lumbosacral spinal cord, we used WGA‐HRP to reconstruct the location of sensory afferent fibers from the perineal skin. We found that these fibers are caudally concentrated relative to the area of the SNB dendritic field, with the rostral dendritic arbor receiving little perineal afferent innervation. We also assessed Fos expression following perineal tactile stimulation to determine whether it increased local spinal cord activity in the SNB dendritic field. Sixty seconds of licking‐like perineal stimulation produced a transient 115% increase in Fos expression in the area of the SNB dendritic field. This effect was driven by a significant increase in Fos in the caudal portion of the SNB dendritic field, matching the pattern of perineal afferent fiber labeling. Perineal tactile stimulation also produced significantly greater Fos expression in male pups than in female pups. Together, these results suggest that perineal sensory afferent activity mediates the effects of early maternal care on the masculinization of the SNB and resultant male copulatory behavior. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009
European governance of natural resources and participation in a multi‐level context: An editorial
Authors: Rauschmayer Felix , Paavola Jouni , Wittmer Heidi
Published: May 2009

Policy markers are looking at two different directions for guidance when addressing the challenges of multi‐level environmental governance in the face of global environmental change. First, they are seeking scientific advice to find solutions to policy problems. Second, they are emphasizing participation of the public and/or stakeholders to enhance the legitimacy of governance. In this editorial we explore the challenges of participation in a multi‐level governance context, outline a practically relevant strategy for research on multi‐level governance of natural resources and briefly outline the key contributions of the five articles that comprise this special issue. The special issue maps issues of key importance for research on multi‐level governance of natural resources rather than offering conclusions from systematic comparative studies – the latter is the ultimate goal of the GoverNat project from which the contributions stem. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
From government to governance for biodiversity: the perspective of central and Eastern European transition countries
Authors: Kluvánková‐Oravská Tatiana , Chobotová Veronika , Banaszak Ilona , Slavikova Lenka , Trifunovova Sonja
Published: May 2009

This paper addresses the problems of institutional changes in governance and the framing of biodiversity conservation policy at the level of the enlarged European Union. The current development of European Union governance has become more complex and multilevel, partially usurping competences from the central state and relying on networks of interconnected actors rather than on a hierarchy dominated and defined by the state. This shift is particularly challenging for biodiversity governance in new member states, where current decision making is still affected by post‐socialist relations and massive ongoing institutional changes, often resulting in inefficient institutional designs and over‐exploitation of natural resources. The paper offers a cross‐country analysis of five Central and Eastern European countries, characterized by different socialist regimes and different transition processes from hierarchical to democratic and market governance. The theoretical basis of the paper is institutional rebuilding in Central and Eastern Europe in the context of the emerging multilevel environmental governance of the EU. The data were collected from desk study research and interviews. The results show that some elements of multilevel governance existed in these countries prior to the transition, but that EU integration empowered lower levels of self‐government. The mismatch between the old hierarchical institutions developed under socialism and the new decentralized institutions introduced during the transformation process still persists and is visible. The emergence of multilevel governance with multiple actors' participation is prone to create tensions, but evidence from the countries studied indicates that this is not necessarily a disadvantage. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Environmental governance: participatory, multi‐level – and effective?
Authors: Newig Jens , Fritsch Oliver
Published: May 2009

Current political trends and scholarly research increasingly promote collaborative and participatory governance in multi‐level systems as a way to more sustainable and effective environmental policy. Yet empirical findings as well as conceptual works from different academic fields remain ambiguous about this claim. This paper explores whether and to what extent the existence of multiple levels of governance affects the ability of participatory decision‐making to deliver high quality environmental policy output and to improve implementation and compliance. To this end, findings from the literature on multi‐level governance, public participation and policy implementation as well as on complex systems are integrated in five sets of hypotheses. In order to put these to a ‘plausibility probe’, a meta‐analysis of 47 case studies from Northern America and Western Europe is conducted. These cases provide qualitative insights and allow for some generalization in the form of correlation analysis. The study finds that, predominantly, environmental preferences of the involved actors determine the environmental outputs (and outcomes) of decision‐making. Further, face‐to‐face, but not mere two‐way, communication appears to positively influence the ecological standard of decisions. The analysis also suggests that a highly polycentric governance system comprising many agencies and levels of governance yields higher environmental outputs than rather monocentric governance. However, correlations between governance effectiveness and decision‐making scale, as well as policy delivery and institutional fit to ecosystem, could not be identified. The paper concludes by outlining pathways for more systematic comparative research on these pressing research questions. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Cationic Rhodium(I)/H8‐binap Complex Catalyzed [2+2+2] Cycloadditions of 1,6‐ and 1,7‐Diynes with Carbonyl Compounds (Eur. J. Org. Chem. 17/2009)
Authors: Otake Yousuke , Tanaka Rie , Tanaka Ken
Published: May 2009

The cover picture shows cationic rhodium(I)/H8‐binap complex catalyzed [2+2+2] cycloadditions of 1,6‐ and 1,7‐diynes with carbonyl compounds, leading to dienones. The present rhodium catalysis allows both electron‐rich and electron‐deficient carbonyl compounds, including acyl phosphonates, to be used. In the reactions involving bifunctional carbonyl compounds or unsymmetrical 1,6‐diynes, high chemo‐ or regioselectivities were observed. Details are discussed in the article by K. Tanaka et al. on p. 2737ff.
Amperometric Ethanol Biosensor Based on Integration of Alcohol Dehydrogenase with Meldola's Blue/Ordered Mesoporous Carbon Electrode
Authors: Jiang Xiaoyan , Zhu Liande , Yang Dongxu , Mao Xuyan , Wu Yanhui
Published: May 2009

An amperometric ethanol biosensor was fabricated by integration of alcohol dehydrogenase (ADH) with meldola's blue (MB)/ordered mesoporous carbon (OMC) composite modified glassy carbon electrode (MB/OMC/GCE). The MB/OMC/GCE was highly sensitive for nicotinamide adenine dinucleotide (NADH) measurement (9.1±0.25 μA/mM) and gave a low detection limit of 0.21±0.02 μM. The ethanol biosensor exhibited a wide linear range up to 6 mM with a lower detection limit of 19.1±0.58 μM as well as a high sensitivity of 34.58±2.43 nA/mM without suffering any interference from some common electroactive compounds.
Suppression of the mouse double minute 4 gene causes changes in cell cycle control in a human mesothelial cell line responsive to ultraviolet radiation exposure
Authors: Bunderson‐Schelvan Melisa , Erbe Amy K. , Schwanke Corbin , Pershouse Mark A.
Published: May 2009

The TP53 tumor suppressor gene is the most frequently inactivated gene in human cancer identified to date. However, TP53 mutations are rare in human mesotheliomas, as well as in many other types of cancer, suggesting that aberrant TP53 function may be due to alterations in its regulatory pathways. Mouse double minute 4 (MDM4) has been shown to be a key regulator of TP53 activity, both independently as well as in concert with its structural homolog, Mouse Double Minute 2 (MDM2). The purpose of this study was to characterize the effects of MDM4 suppression on TP53 and other proteins involved in cell cycle control before and after ultraviolet (UV) exposure in MeT5a cells, a nonmalignant human mesothelial line. Short hairpin RNA (shRNA) was used to investigate the impact of MDM4 on TP53 function and cellular transcription. Suppression of MDM4 was confirmed by Western blot. MDM4 suppressed cells were analyzed for cell cycle changes with and without exposure to UV. Changes in cell growth as well as differences in the regulation of direct transcriptional targets of TP53, CDKN1A (cyclin‐dependent kinase 1α, p21) and BAX, suggest a shift from cell cycle arrest to apoptosis upon increasing UV exposure. These results demonstrate the importance of MDM4in cell cycle regulation as well as a possible role inthe pathogenesis of mesothelioma‐type cancers. Environ. Mol. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.
Average sand particle trajectory examined by the Raindrop Detachment and Wind‐driven Transport (RD‐WDT) process
Authors: Erpul G. , Gabriels D. , Cornelis W. M. , Samray H. , Guzelordu T.
Published: May 2009

Recent studies of soil loss by the integrated action of raindrop impact and wind transport have demonstrated the significance of this mechanism. This paper presents data obtained during wind‐tunnel experiments examining the ‘Raindrop Detachment and Wind‐driven Transport’ (RD‐WDT) process to investigate average sand particle trajectory and the spatial extent at which the process operates. In the experimental design, at the same time as the horizontal wind velocities of 6·4, 10, and 12 m s–1 passed through the tunnel, rainfall was simulated falling on very well sorted dune sand. The aspect and slope of the sand bed was varied to reproduce both windward (Ww) and leeward (Lw) slopes of 4º and 9º with respect to the prevailing wind direction. The average sand particle trajectories by the RD‐WDT process ($\bar X_{RD-WDT}$) were estimated by a mass‐distribution function, which was integrated over a 7‐m uniform slope segment. The results showed that $\bar X_{RD-WDT}$ depended statistically upon the wind shear velocity (u*), and the effect of the slope gradient (θ) was insignificant on $\bar X_{RD-WDT}$. This was different from that of the windless rain process ($\bar X_{RD-ST}$), ‘Raindrop Detachment and Splash‐driven Transport’ (RD‐ST), the spatial range of which relies strongly on θ. Additionally, $\bar X_{RD-WDT}$ was approximately 2·27 ± 2·2 times greater than the average path of a typical saltating sand particle of the rainless wind ($\bar X_{WZ-ST}$), ‘Wind Erosion Saltation Transport’ (WE‐ST). Copyright © 2009 John Wiley & Sons, Ltd.
Compression Properties and Leakage Tests of Mica‐Based Seals for SOFC Stacks
Authors: Rautanen M. , Himanen O. , Saarinen V. , Kiviaho J.
Published: May 2009

Sealing properties and compression properties of two mica‐based materials, Thermiculite 866 and Statotherm HT were measured. Thermiculite 866 was tested in two forms: as‐made and precompressed (consolidated). Sealing tests were carried out at 800 °C with simulated fuel cell anode gas. Seals were pressed to a constant thickness, which represents the conditions in fuel cell stacks. Both seals showed stable leak rates over test periods of roughly 400 h. Leak rates of Thermiculite 866 samples were found to be independent of the hydrogen overpressure within the measurement accuracy in the pressure range of 10–100 mbar(g). However, a Statotherm HT gasket tested with lower compression stress compared to Thermiculite 866 gaskets showed roughly linear dependency on the overpressure. Compression tests were carried out at room temperature and at 800 °C. Compression properties of both materials were found to strongly depend on temperature. Both materials experienced swelling when heated to 800 °C and were more ductile compared to room temperature.
World psychiatric association section of old age psychiatry consensus statement on ethics and capacity in older people with mental disorders
Authors: Katona C. , Chiu E. , Adelman S. , Baloyannis S. , Camus V. , Firmino H. , Gove D. , Graham N. , Ghebrehiwet T. , Icelli I. , Ihl R. , Kalasic A. , Leszek L. , Kim S. , Lima C. de M. , Peisah C. , Tataru N. , Warner J.
Published: May 2009

The World Psychiatric Association (WPA) Section of Old Age Psychiatry, since 1997, has developed Consensus Statements relevant to the practice of Old Age Psychiatry. Since 2006 the Section has worked to develop a Consensus Statement on Ethics and Capacity in older people with mental disorders, which was completed in Prague, September 2008, prior to the World Congress in Psychiatry. This Consensus meets one of the goals of the WPA Action Plan 2008–2011, ”to promote the highest ethical standards in psychiatric practice and advocate the rights of persons with mental disorders in all regions of the world“. This Consensus Statement offers to mental health clinicians caring for older people with mental disorders, caregivers, other health professionals and the general public the setting out of and discourse in ethical principles which can often be complex and challenging, supported by practical guidance in meeting such ethical needs and standards, and to encouraged good clinical practice. Copyright © 2009 John Wiley & Sons, Ltd.
Curcumin sensitizes human colorectal cancer to capecitabine by modulation of cyclin D1, COX‐2, MMP‐9, VEGF and CXCR4 expression in an orthotopic mouse model
Authors: Kunnumakkara Ajaikumar B. , Diagaradjane Parmeswaran , Anand Preetha , Kuzhuvelil Harikumar B. , Deorukhkar Amit , Gelovani Juri , Guha Sushovan , Krishnan Sunil , Aggarwal Bharat B.
Published: May 2009

Because of the poor prognosis and the development of resistance against chemotherapeutic drugs, the current treatment for advanced metastatic colorectal cancer (CRC) is ineffective. Whether curcumin (a component of turmeric) can potentiate the effect of capecitabine against growth and metastasis of CRC was investigated. The effect of curcumin on proliferation of CRC cell lines was examined by mitochondrial dye‐uptake assay, apoptosis by esterase staining, nuclear factor‐kappaB (NF‐κB) by electrophoretic mobility shift assay and gene expression by Western blot analysis. The effect of curcumin on the growth and metastasis of CRC was also examined in orthotopically implanted tumors in nude mice. In vitro, curcumin inhibited the proliferation of human CRC cell lines, potentiated capecitabine‐induced apoptosis, inhibited NF‐κB activation and suppressed NF‐κB‐regulated gene products. In nude mice, the combination of curcumin and capecitabine was found to be more effective than either agent alone in reducing tumor volume (p = 0.001 vs. control; p = 0.031 vs. capecitabine alone), Ki‐67 proliferation index (p = 0.001 vs. control) and microvessel density marker CD31. The combination treatment was also highly effective in suppressing ascites and distant metastasis to the liver, intestines, lungs, rectum and spleen. This effect was accompanied by suppressed expression of activated NF‐κB and NF‐κB‐regulated gene products (cyclin D1,c‐myc, bcl‐2, bcl‐xL, cIAP‐1, COX‐2, ICAM‐1, MMP‐9, CXCR4 and VEGF). Overall, our results suggest that curcumin sensitizes CRC to the antitumor and antimetastatic effects of capecitabine by suppressing NF‐κB cell signaling pathway. © 2009 UICC
Understanding the mechanism of the dormant dauer formation of C. elegans: From genetics to biochemistry
Authors: Wang Yunbiao , Ezemaduka Anastasia N. , Tang Yan , Chang Zengyi
Published: May 2009

Dauer is a dormancy state that may occur at the end of developmental stage L1 or L2 of Caenorhabditis elegans when the environmental conditions are unfavorable (e.g., lack of food, high temperature, or overcrowding) for further growth. Dauer is a nonaging duration that does not affect the postdauer adult lifespan. Major molecular events would include the sensing of the environmental cues, the transduction of the signals into the cells, and the subsequent integration of the signals that result in the corresponding alteration of the metabolism and morphology of the organism. Genetics approach has been effectively used in identifying many of the so‐called daf genes involved in dauer formation using C. elegans as the model. Nevertheless, biochemical studies at the protein and metabolic level has been lacking behind in understanding this important life phenomenon. This review focuses on the biochemical understanding so far achieved on dauer formation and dormancy in general, as well as important issues that need to be addressed in the future. © 2009 IUBMB IUBMB Life, 61(6): 607–612, 2009
Protein thermodynamic structure
Authors: Zhao Qinyi
Published: May 2009

Protein research is generally recognized as experimental science and knowledge of protein science is not constructed axiomatically. In this article, we show that much of our present knowledge of protein science is explainable by principles of protein thermodynamic structure theory. A deductive system for protein knowledge has been developed and several fundamental questions of protein science can be theoretically resolved. © 2009 IUBMB IUBMB Life, 61(6): 600–606, 2009
Tax1 enhances cancer cell proliferation via Ras–Raf–MEK–ERK signaling pathway
Authors: Song Chunjiao , Wang Weimin , Li Meng , Liu Yanxin , Zheng Dexian
Published: May 2009

Erbin is an ErbB2 binding protein, which belongs to the LAP (leucine‐rich repeat (LRR) and PDZ domain) protein family. We previously reported that Tax1, a protein of the human T‐cell leukemia virus type I (HTLV‐I), associated with Erbin by using Erbin PDZ domain as a bait to screen a human T lymphocyte cDNA library by a yeast two hybrid strategy. In the present study, we demonstrated that Tax1 enhances cancer cell proliferation via Ras–Raf–MEK–ERK signaling pathway by using molecular section strategy. The pull‐down assay showed that the four amino acid domain, that is, Tax1 350–353, might specifically interact with Erbin, but not any other Tax1 deletion mutants. The coimmunoprecipitation assay confirmed that Tax1 350–353 domain bound with Erbin in vivo. Functional study demonstrated that overexpresssion of Tax1 in cancer cell lines of liver cancer SMMC‐7721, colon cancer HCT‐116, and breast cancer MCF‐7 facilitated the cell proliferation. And the transfection of Tax1 353 in MCF‐7 cells with endogenous Erbin expression markedly increased phosphorylation of Ras, Raf, MEK1/2, ERK1/2, PI3K, and IκBα, suggesting that Tax1‐enhanced cell proliferation tracks Ras–Raf–MEK–ERK signaling pathway. © 2009 IUBMB IUBMB Life, 61(6): 685–692, 2009
Protein folding simulations: From coarse‐grained model to all‐atom model
Authors: Zhang Jian , Li Wenfei , Wang Jun , Qin Meng , Wu Lei , Yan Zhiqiang , Xu Weixin , Zuo Guanghong , Wang Wei
Published: May 2009

Protein folding is an important and challenging problem in molecular biology. During the last two decades, molecular dynamics (MD) simulation has proved to be a paramount tool and was widely used to study protein structures, folding kinetics and thermodynamics, and structure–stability–function relationship. It was also used to help engineering and designing new proteins, and to answer even more general questions such as the minimal number of amino acid or the evolution principle of protein families. Nowadays, the MD simulation is still undergoing rapid developments. The first trend is to toward developing new coarse‐grained models and studying larger and more complex molecular systems such as protein–protein complex and their assembling process, amyloid related aggregations, and structure and motion of chaperons, motors, channels and virus capsides; the second trend is toward building high resolution models and explore more detailed and accurate pictures of protein folding and the associated processes, such as the coordination bond or disulfide bond involved folding, the polarization, charge transfer and protonate/deprotonate process involved in metal coupled folding, and the ion permeation and its coupling with the kinetics of channels. On these new territories, MD simulations have given many promising results and will continue to offer exciting views. Here, we review several new subjects investigated by using MD simulations as well as the corresponding developments of appropriate protein models. These include but are not limited to the attempt to go beyond the topology based Gō‐like model and characterize the energetic factors in protein structures and dynamics, the study of the thermodynamics and kinetics of disulfide bond involved protein folding, the modeling of the interactions between chaperonin and the encapsulated protein and the protein folding under this circumstance, the effort to clarify the important yet still elusive folding mechanism of protein BBL, the development of discrete MD and its application in studying the α–β conformational conversion and oligomer assembling process, and the modeling of metal ion involved protein folding. © 2009 IUBMB IUBMB Life, 61(6): 627–643, 2009
Plasminogen activator inhibitors regulate cell adhesion through a uPAR‐dependent mechanism
Authors: Czekay Ralf‐Peter , Loskutoff David J.
Published: May 2009

Binding of type‐1 plasminogen activator inhibitor (PAI‐1) to cell surface urokinase (uPA) promotes inactivation and internalization of adhesion receptors (e.g., urokinase receptor (uPAR), integrins) and leads to cell detachment from a variety of extracellular matrices. In this report, we begin to examine the mechanism of this process. We show that neither specific antibodies to uPA, nor active site inhibitors of uPA, can detach the cells. Thus, cell detachment is not simply the result of the binding of macromolecules to uPA and/or of the inactivation of uPA. We further demonstrate that another uPA inhibitor, protease nexin‐1 (PN‐1), also stimulates cell detachment in a uPA/uPAR‐dependent manner. The binding of both inhibitors to uPA leads to the specific inactivation of the matrix‐engaged integrins and the subsequent detachment of these integrins from the underlying extracellular matrix (ECM). This inhibitor‐mediated inactivation of integrins requires direct interaction between uPAR and those integrins since cells attached to the ECM through integrins incapable of binding uPAR do not respond to the presence of either PAI‐1 of PN‐1. Although both inhibitors initiate the clearance of uPAR, only PAI‐1 triggers the internalization of integrins. However, cell detachment by PAI‐1 or PN‐1 does not depend on the endocytosis of these integrins since cell detachment was also observed when clearance of these integrins was blocked. Thus, PAI‐1 and PN‐1 induce cell detachment through two slightly different mechanisms that affect integrin metabolism. These differences may be important for distinct cellular processes that require controlled changes in the subcellular localization of these receptors. J. Cell. Physiol. 220: 655–663, 2009. © 2009 Wiley‐Liss, Inc.
Improved arterial visibility using short‐tau inversion‐recovery (STIR) fat suppression in non‐contrast‐enhanced time–spatial labeling inversion pulse (Time‐SLIP) renal MR angiography (MRA)
Authors: Shonai Takaharu , Takahashi Tadashi , Ikeguchi Hiroaki , Miyazaki Mitsue , Amano Kiyoka , Yui Masao
Published: May 2009

Purpose

To evaluate whether short‐tau inversion‐recovery (STIR) fat suppression is worthwhile in non‐contrast‐enhanced respiration‐triggered free‐breathing time–spatial labeling inversion pulse (Time‐SLIP) renal magnetic resonance angiography (MRA) compared with chemical shift selective (CHESS) fat suppression.

Materials and Methods

Simulation‐based analyses of inversion time (TI) for spatial‐selective inversion‐recovery (ssIR) pulse and breathing rate were performed, and confirmed on a phantom and in human subjects using a three‐dimensional (3D) coherent steady‐state free precession (SSFP) sequence on a 1.5T Toshiba scanner.

Results

The STIR fat suppression successfully suppressed signals from the intestines and parenchymous organs and provided better contrast between the arteries and the background, although an extension of TI was required for the ssIR pulse when a patient's respiration was extremely slow.

Conclusion

STIR fat suppression provides better renal artery contrast than CHESS fat suppression in non‐contrast free‐breathing Time‐SLIP MRA; it is also an effective screening tool for renal artery stenosis because of the lack of interference from intestinal signals. However, close attention is needed if the patient has slow respiration. As the TI for the ssIR pulse decreases, the STIR method requires faster‐paced respiration. J. Magn. Reson. Imaging 2009;29:1471–1477. © 2009 Wiley‐Liss, Inc.
MR study of postnatal development of myocardial structure and left ventricular function
Authors: Wu Yin , Wu Ed X.
Published: May 2009

Purpose

To investigate postnatal development of left ventricular (LV) cardiac function and myocardium structure.

Materials and Methods

In vivo cardiac MR and ex vivo diffusion tensor imaging (DTI) were performed in normal Sprague‐Dawley rats at postnatal day 2, 4, 7, 14, 21, 28, and 56 (N = 6 per group).

Results

Morphologically, LV size increased with age. Functionally, stroke volume and cardiac output increased. Heart rate increased gradually and became stable after day 14. On average, ejection fraction increased within the first 4 days, decreased at day 7, gradually increased until day 21, and became stable afterward. Structurally, double‐helical myocardial structure was found as early as day 2. Myocardial fiber parameters, described by fractional anisotropy, mean apparent diffusion coefficient, and axial diffusivity, increased within the first 4 days. Then radial diffusivity increased until day 7 while other parameters decreased up to day 56.

Conclusion

Postnatal heart development was documented by MRI. DTI findings are in agreement with the two known stages of early postnatal growth: hyperplasia and hypertrophy. These results can serve as the baselines for study of postnatal heart developmental abnormalities. They also demonstrate the ability of DTI to reveal microstructural alterations in myocardium. J. Magn. Reson. Imaging 2009;30:47–53. © 2009 Wiley‐Liss, Inc.
Metastable atom‐activated dissociation mass spectrometry: leucine/isoleucine differentiation and ring cleavage of proline residues
Authors: Cook Shannon L. , Collin Olivier L. , Jackson Glen P.
Published: May 2009

Extensive backbone fragmentation resulting in a‐, b‐, c‐, x‐, y‐ and z‐type ions is observed of singly and doubly charged peptide ions through their interaction with a high kinetic energy beam of argon or helium metastable atoms in a modified quadrupole ion trap mass spectrometer. The ability to determine phosphorylation‐sites confirms the observation with previous reports and we report the new ability to distinguish between leucine and isoleucine residues and the ability to cleave two covalent bonds of the proline ring resulting in a‐, b‐, x‐, y‐, z‐ and w‐type ions. The fragmentation spectra indicate that fragmentation occurs through nonergodic radical ion chemistry akin to electron capture dissociation (ECD), electron transfer dissociation (ETD) and electron ionization dissociation mechanisms. However, metastable atom‐activated dissociation mass spectrometry demonstrates three apparent benefits to ECD and ETD: (1) the ability to fragment singly charged precursor ions, (2) the ability to fragment negatively charged ions and (3) the ability to cleave the proline ring that requires the cleavage of two covalent bonds. Helium metastable atoms generated more fragment ions than argon metastable atoms for both substance P and bradykinin regardless of the precursor ion charge state. Reaction times less than 250 ms and efficiencies approaching 5% are compatible with on‐line fragmentation, as would be desirable for bottom‐up proteomics applications. Copyright © 2009 John Wiley & Sons, Ltd.
Proliferation deficits and gene expression dysregulation in Down's syndrome (Ts1Cje) neural progenitor cells cultured from neurospheres
Authors: Moldrich Randal X. , Dauphinot Luce , Laffaire Julien , Vitalis Tania , Hérault Yann , Beart Philip M. , Rossier Jean , Vivien Denis , Gehrig Corinne , Antonarakis Stylianos E. , Lyle Robert , Potier Marie‐Claude
Published: May 2009

Down's syndrome neurophenotypes are characterized by mental retardation and a decreased brain volume. To identify whether deficits in proliferation could be responsible for this phenotype, neural progenitor cells were isolated from the developing E14 neocortex of Down's syndrome partial trisomy Ts1Cje mice and euploid (WT) littermates and grown as neurospheres. Ts1Cje neural progenitors proliferated at a slower rate, because of a longer cell cycle, and a greater number of cells were positive for glial fibrillary acidic protein. An increase in cell death was also noted. Gene expression profiles of neural progenitor cells from Ts1Cje and WT showed that 54% of triploid genes had expression ratios (Ts1Cje/WT) significantly greater than the expected diploid gene ratio of 1.0. Some diploid genes associated with proliferation, differentiation, and glial function were dysregulated. Interestingly, proliferation and gene expression dysregulation detected in the Ts1Cje mice did not require overexpression of the chromosome 21 genes amyloid precursor protein (App) and soluble superoxide dismutase 1 (Sod1). © 2009 Wiley‐Liss, Inc.
Improved simulation of Australian climate and ENSO‐related rainfall variability in a global climate model with an interactive aerosol treatment
Authors: Rotstayn Leon D. , Collier Mark A. , Dix Martin R. , Feng Yan , Gordon Hal B. , O'Farrell Siobhan P. , Smith Ian N. , Syktus Jozef
Published: May 2009

We assess the simulation of Australian mean climate and rainfall variability in a new version of the CSIRO coupled ocean–atmosphere global climate model (GCM). The new version, called Mark 3.6 (Mk3.6), differs from its recent predecessors (Mk3.0 and Mk3.5) by inclusion of an interactive aerosol scheme, which treats sulfate, dust, sea salt and carbonaceous aerosol. Other changes include an updated radiation scheme and a modified boundary‐layer treatment. Comparison of the mean summer and winter climate simulations in Mk3.6 with those in Mk3.0 and Mk3.5 shows several improvements in the new version, especially regarding winter rainfall and sea‐level pressure. The improved simulation of Australian mean seasonal climate is confirmed by calculation of a non‐dimensional skill score (the ‘M‐statistic’), using data from all four seasons. However, the most dramatic improvement occurs in the model's simulation of the leading modes of annual rainfall variability, which we assess using empirical orthogonal teleconnections (EOTs). Compared to its predecessors and several international GCMs, Mk3.6 is best able to capture the spatial pattern of the leading rainfall mode, which represents variability due to the El Niño Southern Oscillation (ENSO). Mk3.6 is also best able to capture the spatial pattern of the second rainfall mode, which corresponds to increased rainfall in the northwest, and decreased rainfall over eastern Australia. We propose a possible mechanism for the improved simulation of rainfall variability in terms of the role of interactive dust in Mk3.6. By further suppressing convection over eastern Australia during El Niño events, dust feedbacks may enhance rainfall variability there, in tune with the model's ENSO cycle. This suggests that an interactive aerosol treatment may be important in a GCM used for the study of Australian climate change and variability. Mechanistic sensitivity studies are needed to further evaluate this hypothesis. Copyright © 2009 Royal Meteorological Society
SPECT‐CT compared with conventional imaging modalities for the assessment of the varus and valgus malaligned hindfoot
Authors: Knupp Markus , Pagenstert Geert I. , Barg Alexej , Bolliger Lilianna , Easley Mark E. , Hintermann Beat
Published: May 2009

The combined single‐photon emission computed tomography and conventional computed tomography (SPECT/CT) technique has increased the sensitivity and specificity of bone scans. We examined the value of using SPECT/CT for the assessment of coronal plane hindfoot deformities. Twenty‐seven patients with varus (11 patients) or valgus (16 patients) malalignment of the hindfoot were assessed using radiography, conventional CT, bone scintigraphy, and SPECT/CT. The amount of deformity, stage of osteoarthritis, and level of activation on bone scans and SPECT/CT were measured. Activation was assessed in 12 regions of interest. The stage of osteoarthritis seen on plain radiographs correlated significantly with the level of activation detected on bone scans (p < 0.05). No correlation was observed between the amount of deformation and activity, and between bone scan activation and signs of osteoarthritis on CT scans. The varus malaligned ankles showed higher radioisotope uptake in the medial areas, while the valgus malaligned ankles showed increased uptake in the lateral areas (p < 0.05). SPECT/CT may be a valuable tool for the assessment and staging of osteoarthritis. Our findings underline the adverse effects of coronal plane deformity of the hindfoot. In addition, results from this study provide useful information for future basic research on coronal plane deformity of the hindfoot and for determining appropriate surgical approaches. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1461–1466, 2009
Measuring stresses in thin metal films by means of Raman microscopy using silicon as a strain gage material
Authors: Wermelinger Thomas , Charpentier Christophe , Yüksek Müge Deniz , Spolenak Ralph
Published: May 2009

Mechanical stresses in microelectronics and micro‐electromechanical systems may influence the reliability of applications and devices. The origin of the stresses can be because of the joining of dissimilar materials with regard to the thermal expansion coefficient, electromigration or the deposition process utilized. Stresses can lead to delamination, crack formation and stress migration and therefore to a failure of the device. Identifying the locations of highest stresses in a device is crucial for reliability improvement. Currently, both Laue X‐ray micro diffraction and convergent‐beam electron diffraction are able to locally determine the stresses in thin metal films. Here, we propose a modified method of indirect Raman microspectroscopy to measure stresses with a lateral resolution in the submicrometer range at a laboratory scale. The method encompasses the crystallization of an amorphous silicon layer by local laser annealing and its subsequent usage as a strain gage. Stresses in an aluminum thin film were determined as a function of temperature. In addition to the average stress, the stress distribution could be monitored. Copyright © 2009 John Wiley & Sons, Ltd.
The role of guidelines in quality improvement for cancer surgery
Authors: Browman George P. , Brouwers Melissa
Published: May 2009

In February 2008, Cancer Surgery Alberta hosted a conference on surgical outcomes and quality. The objective here is to review the interactions between quality/outcomes and guidelines, highlighting surgeons' roles. Potential interactions between quality measurement and guidelines are discussed. We analyzed data from practitioner surveys about guidelines to determine surgeons' participation compared with other specialists. The response rate of surgeons in both community‐based and academic practices to guideline development surveys was equivalent to other cancer disciplines. J. Surg. Oncol. 2009;99:467–469. © 2009 Wiley‐Liss, Inc.
Outcome—more than just operative mortality
Authors: Brennan Murray F. , Radzyner Mark , RubIn David M.
Published: May 2009

Historical reviews of outcome following major operations for cancer have focused on the readily measurable, operative mortality. The interrelationship of surgeon and institutional volume to improved perioperative outcome has been confirmed. More current studies now relate long term cancer survival to other issues of specialization, volume, payor and institution. The challenge is to determine what volume thresholds are sufficient for acceptable outcomes. J. Surg. Oncol. 2009;99:470–477. © 2009 Wiley‐Liss, Inc.
Standardized synoptic cancer pathology reporting: A population‐based approach
Authors: Srigley John R. , McGowan Tom , MacLean Andrea , Raby Marilyn , Ross Jillian , Kramer Sarah , Sawka Carol
Published: May 2009

Cancer pathology reports contain information which is critical for patient management and for cancer surveillance, resource planning, and quality purposes. The College of American Pathologists (CAP) has defined scientifically validated content of checklists that form the basis for synoptic cancer pathology reporting. We outline how the CAP standards were implemented in a large Canadian province over a 3‐year period resulting in improvements in rates of synoptic reporting and completeness of cancer pathology reporting. J. Surg. Oncol. 2009;99:517–524. © 2009 Wiley‐Liss, Inc.
Synthesis and application of novel phenylboronate affinity materials based on organic polymer particles for selective trapping of glycoproteins
Authors: Preinerstorfer Beatrix , Lämmerhofer Michael , Lindner Wolfgang
Published: May 2009

We report on synthesis concepts for the fabrication of various novel phenylboronate affinity materials based on polymethacrylate epoxy beads (Fractogel® EMD Epoxy (M) 40–90 μm) and the testing of these functionalized polymer particles for selective trapping of a glycoprotein from a standard mixture containing a glycosylated and a nonglycosylated protein. Two inherently different approaches for the functionalization of the bare beads with boronate groups have been elucidated. In the first, the epoxy residues of the polymer particles were converted into reactive thiol groups which were subsequently used as anchor moieties for the immobilization of 4‐vinylphenylboronic acid by radical addition or radical polymerization reaction. Three different ways for the generation of sulfhydryl groups have been examined leading to materials with distinct linker chemistries. In the second and more straightforward approach, the epoxy groups were reacted with 4‐mercaptophenylboronic acid. The novel materials were thoroughly characterized by (i) quantitation of the sulfur content by elemental analysis, (ii) reactive sulfhydryls were determined in a photospectrometric assay, (iii) boron content was measured by inductively coupled plasma‐atomic emission spectrometry, and (iv) the amount of reactive boronate groups was evaluated in a fast binding assay employing adenosine as test compound. A maximum concentration of 1.2 mmol boronate groups per gram dry beads could be achieved by the presented synthesis routes. Employing the novel phenylboronate affinity materials in capture and release experiments in the batch mode, a standard glycoprotein, viz. transferrin (Tf) from human serum was separated from a nonglycosylated protein, BSA. A commercial boronate affinity material based on 3‐aminophenylboronic acid modified agarose gel was employed as reference material and was found to perform significantly worse compared to the herein presented novel polymethacrylate particles.
Screening of acetylcholinesterase inhibitors by CE after enzymatic reaction at capillary inlet
Authors: Martín‐Biosca Yolanda , Asensi‐Bernardi Lucia , Villanueva‐Camañas Rosa M. , Sagrado Salvador , Medina‐Hernández Maria J.
Published: May 2009

In this study the development of a procedure based on capillary electrophoresis after enzymatic reaction at capillary inlet methodology for the screening and in vitro evaluation of the biological activity of acetylcholinesterase (AChE) inhibitors is presented. The progress of the enzymatic reaction of the hydrolysis of acetylthiocholine at pH 8 in the presence of AChE and the inhibitor studied is determined by measuring at 230 nm the peak area of the reaction product thiocholine (TCh). In the method employed the capillary was first filled with 30 mM borate‐phosphate buffer (pH 8.0) and subsequently, plugs of: (i) water, (ii) AChE solution, (iii) substrate solution with or without inhibitor, (iv) AChE solution, and (v) water, were hydrodynamically injected into the capillary, and were allowed to stand (and react) during a waiting period of 2 min. The applicability of the proposed methodology to estimate different kinetic parameters of interest such as inhibition constants Ki, identification of inhibitory action mechanism and IC50, is evaluated using compounds with known activity, tacrine edrophonium, and neostigmine. The results obtained are compared with bibliographic values and confirm the effectiveness of the methodology proposed. Finally a method for AChE Inhibitor screening is proposed.
Application of immunoaffinity capillary electrophoresis to the measurements of secreted cytokines by cultured astrocytes
Authors: Kalish Heather , Phillips Terry M.
Published: May 2009

The ability of the central nervous system (CNS) to act in conjunction with the immune system has been of great interest to both neurobiologists and immunologists. Previous studies have shown that astrocytes can be stimulated, by various peptides, to act as immune regulators within the CNS and release cytokines and chemokines. However, the regulatory mechanism of astrocytes is still poorly understood. Our present study describes a micro‐device capable of monitoring the growth and stimulation of 20 astrocytes by vasoactive intestinal peptide. A microdialysis needle was used to collect the secretion by products, which were analyzed by immunoaffinity capillary electrophoresis (ICE) for the secretion of pro‐inflammatory cytokines, IL‐1α, IL‐1β, IL‐6, and tumor necrosis factor (TNF)‐α; hemopoetic cytokines, IL‐3, granulocyte colony‐stimulating factor (G‐CSF), macrophage colony‐stimulating factor (M‐CSF), granulocyte/macrophage colony‐stimulating factor (GM‐CSF); and chemokines; regulated upon activation normal T‐cell expression sequence (RANTES), macrophage inflammatory protein (MIP)‐1α and MIP‐1β. Vasoactive intestinal peptide stimulated astrocytes showed an almost immediate release of pro‐inflammatory cytokines and chemokines, with an increase over baseline ranging from 3 to 15 fold, while no substantial increase over baseline was observed for hemopoetic cytokines. This system demonstrates the ability to isolate individual cells in a closely controlled environment and identify and quantify their analytes.
Fast gas chromatography: Applications in milk fat analysis
Authors: Povolo Milena , Contarini Giovanna
Published: May 2009

In our society saving time is important because time is money. For this reason the development of instrumentation able to perform analytical determinations with a high speed is an on‐going matter, particularly regarding routine control analyses. In the last few years the possibility of performing gas chromatographic analysis in a very short time has been increasing. In this paper a general overview of fast chromatography and our experience of its application to the analysis of milk fat triacylglycerols is reported.