bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxazole Cyclopeptides for Chirality Transfer in C3‐Symmetric Octahedral Metal Complexes
Authors: Pintér Áron , Haberhauer Gebhard
Published: March 2008

A straightforward synthesis of C3‐symmetric oxazole‐containing macrocyclic peptide scaffolds is presented. This type of macrocycles bears three functional groups on the oxazole rings, which allows fixing of various receptor arms on them in an easy manner. The chiral backbone of the macrocycle proved to be a powerful tool for chirality induction, thus predetermining the configuration of helically coordinated metal centres. The diastereoselective formation of CoII, NiII, CuII and ZnII complexes with tripodal bipyridyl ligand 4 was proved by UV‐ and CD‐absorption spectrophotometric titration experiments.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Considering safety issues in minimum losses reconfiguration for MV distribution networks
Authors: Campoccia Angelo , Sanseverino Eleonora Riva , Zizzo Gaetano
Published: March 2008

This paper offers a new perspective over the traditional problem of the multiobjective optimal reconfiguration of electrical distribution systems in regular working state. The issue is indeed here formulated including also safety issues. Indeed, dimensioning the earth electrodes of their own secondary substations, distribution companies take into account the probable future configurations of the network due to transformations of overhead lines into cable lines or realization of new lines. On the contrary, they do not consider that, during normal working conditions, the structure of the network can be modified for long periods as a consequence of reconfiguration manoeuvres, with differences between the design current of the earthing systems and the fault current in certain substations significant. As a consequence, often distribution companies limit the implementation of the optimal reconfiguration layouts because they are unable to suitably evaluate the safety issue. In the paper, the problem is formulated including a further objective in order to account for the safety. A suitable constrained multiobjective formulation of the reconfiguration problem is therefore used aiming at: the minimal power losses operation, the verification of safety at distribution substations, the load balancing among the HV/MV transformers while keeping the voltage profile regular. The application carried out uses an NSGA‐II algorithm whose performance is compared to that of a fuzzy logic‐based multiobjective evolutionary algorithm. In the considered automated network, the remote control of tie‐switches is possible and their layout is the optimization variable. After a brief description of the optimal reconfiguration problem for automated distribution networks, the most recent papers on the topic are reported and commented. Then the problem formulation and the solution algorithm are described in detail. Finally, test results on a large MV distribution network are reported and discussed. Copyright © 2008 John Wiley & Sons, Ltd.
The assessment of the impacts of the security management in a competitive environment
Authors: Bompard Ettore , Carpaneto Enrico , Ciwei Gao , Napoli Roberto , Demartini Giovanni , Vimercati Giuliano
Published: March 2008

Security management is of the utmost importance in power system and many efforts have been made on this issue since a reliable supply of electricity is crucial to the modern societies. The traditional approach adopted in Europe is based on the “n − 1” steady‐state security that is efficient, although restrictive, and can continue to play an important role also in the new competitive context. In this paper, three alternative market‐based models for security consideration are introduced, according to preventive and corrective control approaches. The models are presented and analyzed in terms of their economic impacts on the market throughout a set of useful indexes that allows for a ranking of the advantages got from the re‐enforcement of the lines. Moreover, the positive impacts of the phase‐shifter (PS) installation for the security and congestion management are quantified and indexes are derived to assess their optimal location. The different models and the exploitation of the proposed indexes are illustrated with reference to a 34‐bus test system. Copyright © 2008 John Wiley & Sons, Ltd.
Non‐superconducting fault current limiters
Authors: Hagh M. Tarafdar , Abapour M.
Published: March 2008

This paper proposes the use of non‐superconducting DC reactor type fault current limiter (NSFCL) instead of superconducting fault current limiters (SFCLs) which has high cost and technology. Proposed FCL consists of three similar sets, each including a diode bridge and a single non‐superconducting DC reactor. The device is connected in series with distribution line and it has almost no effect on the normal system operation. It is not necessary to use a control circuit and it has a simple and cheap power circuit. Design characteristics, analytical analysis and overall transient and steady‐state performance of NSFCL in normal and fault conditions are presented in this paper. The comparison between experimental and simulation results indicate good agreements. The results confirm that the power loss of NSFCL is a very small percentage of distribution line power. Also, the system current and load voltage distortions due to using NSFCL is explained and simulated. Copyright © 2008 John Wiley & Sons, Ltd.
Autonomous power system for island or grid‐connected wind turbines in distributed generation
Authors: Iwanski Grzegorz , Koczara Wlodzimierz
Published: March 2008

Modern power generation systems for wind turbines are often based on the rotor fed slip‐ring machines. Power electronics converter provides the slip power, and also the reactive power for excitation of the generator during standalone operation. This way the isolated load can be supplied even if the grid has failed. Stator voltage in an autonomous operation is controlled using vectorial phase locked loop (PLL) structure; therefore the information about mechanical speed or angular position of the rotor is eliminated from the control method. The second PLL is also used for synchronization of the generated voltage with the grid voltage. Voltages synchronization is necessary for soft connection and protection of the supplied load from the rapid change of the supply voltage phase. The grid‐connected doubly fed induction generator (DFIG) can be useful after grid fault; however, the mains outage detection methods are necessary for fast disconnection after grid failures. Copyright © 2008 John Wiley & Sons, Ltd.
A reduced‐order simulated annealing approach for four‐dimensional variational data assimilation in meteorology and oceanography
Authors: Hoteit I.
Published: March 2008

Four‐dimensional variational data assimilation in meteorology and oceanography suffers from the presence of local minima in the cost function. These local minima arise when the system under study is strongly nonlinear. The number of local minima further dramatically increases with the length of the assimilation period and often renders the solution to the problem intractable. Global optimization methods are therefore needed to resolve this problem. However, the huge computational burden makes the application of these sophisticated techniques unfeasible for large variational data assimilation systems. In this study, a Simulated Annealing (SA) algorithm, complemented with an order‐reduction of the control vector, is used to tackle this problem. SA is a very powerful tool of combinatorial minimization in the presence of several local minima at the cost of increasing the execution time. Order‐reduction is then used to reduce the dimension of the search space in order to speed up the convergence rate of the SA algorithm. This is achieved through a proper orthogonal decomposition. The new approach was implemented with a realistic eddy‐permitting configuration of the Massachusetts Institute of Technology general circulation model (MITgcm) of the tropical Pacific Ocean. Numerical results indicate that the reduced‐order SA approach was able to efficiently reduce the cost function with a reasonable number of function evaluations. Copyright © 2008 John Wiley & Sons, Ltd.
On CFL evolution strategies for implicit upwind methods in linearized Euler equations
Authors: Bücker H. M. , Pollul B. , Rasch A.
Published: March 2008

In implicit upwind methods for the solution of linearized Euler equations, one of the key issues is to balance large time steps, leading to a fast convergence behavior, and small time steps, needed to sufficiently resolve relevant flow features. A time step is determined by choosing a Courant–Friedrichs–Levy (CFL) number in every iteration. A novel CFL evolution strategy is introduced and compared with two existing strategies. Numerical experiments using the adaptive multiscale finite volume solver QUADFLOW demonstrate that all three CFL evolution strategies have their advantages and disadvantages. A fourth strategy aiming at reducing the residual as much as possible in every time step is also examined. Using automatic differentiation, a sensitivity analysis investigating the influence of the CFL number on the residual is carried out confirming that, today, CFL control is still a difficult and open problem. Copyright © 2008 John Wiley & Sons, Ltd.
Die Königsdisziplin und ihr Meister
Authors: Unterstell Rembert
Published: March 2008

Algebraische Topologie: Leibniz‐Preisträger Wolfgang Lück erforscht fundamentale Fragen, die sogar manchem Mathematiker zu theoretisch sind
Erfolg auf wackeligen Beinen
Authors: Gehrke Hans‐Joachim
Published: March 2008

Die Förderinitiative der DFG stützt die Geisteswissenschaften – doch Mittelkürzungen und Verwertungsdenken bedrohen sie weiter
Fettsäuren im Fokus
Authors: Steinhart Hans
Published: March 2008

Mehrfach ungesättigte Fettsäuren kennt jeder – über Minorfettsäuren wissen Verbraucher und Forscher dagegen nur wenig. In aufwendiger Arbeit erkunden Lebensmittelchemiker jetzt ihr Vorkommen und ihre Bedeutung für die Ernährung
Further evidence for a crucial role of resident endoneurial macrophages in peripheral nerve disorders: Lessons from acrylamide‐induced neuropathy
Authors: Müller Marcus , Wacker Karin , Getts Daniel , Ringelstein Erich Bernd , Kiefer Reinhard
Published: March 2008

Endoneurial macrophages are crucially involved in the pathogenesis of neuropathies. Historically, the macrophage response in neuropathies is believed to be of hematogenous origin. However, recent studies could demonstrate an intrinsic generation of the early macrophage response by resident endoneurial macrophages after traumatic nerve injury and in a model of hereditary neuropathy. We hypothesized that the local macrophage response might suffice to generate an appropriate macrophage response in mild neuropathies, supplemented by infiltrating macrophages only in severe nerve pathology. To clarify this assumption, we investigated the macrophage response in acrylamide‐induced neuropathy as a model of a slowly progressive neuropathy with a defined onset. We induced the neuropathy in bone marrow chimeric mice carrying green fluorescent protein transgenic bone marrow, allowing the differentiation of resident (GFP−) and invading hematogenous endoneurial (GFP+) macrophages. Quantification of GFP− and GFP+ endoneurial macrophages in the sciatic nerve revealed an increase only of resident macrophages in proximal parts, whereas in distal parts a minor additional influx of hematogenous macrophages was observed. The immunohistochemical profile of GFP− and GFP+ macrophages was similar but distal GFP− macrophages were differentially activated than their GFP+ counterparts. Characterization of CCR2‐deficient mice revealed a function for this chemokine system in attracting hematogenous macrophages but not in generating the intrinsic macrophage response. In conclusion, we provide evidence for a role of resident macrophages in acrylamide‐induced neuropathy. Resident endoneurial macrophages intrinsically generate the macrophage response in this slowly progressive neuropathy, which only becomes supplemented by hematogenous macrophages in distal areas of more pronounced damage. © 2008 Wiley‐Liss, Inc.
Coping strategies, anxiety and depression in caregivers of people with Alzheimer's disease
Authors: Cooper Claudia , Katona Cornelius , Orrell Martin , Livingston Gill
Published: March 2008

Objectives

There have been few longitudinal studies investigating the impact of coping on psychological morbidity in caregivers of people with dementia. Findings have been inconsistent and little attention has been paid to anxiety in caregivers. We explored the hypothesis that the relationship between caregiver burden and anxiety and depression is mediated by coping style.

Methods

As part of the LASER‐AD study, 93 (73.8%) people with Alzheimer's disease and their family caregivers recruited at baseline were re‐interviewed 1 year later. Sampling aimed to ensure that the participants were representative of people living in the UK with Alzheimer's disease in terms of dementia severity, gender and care setting. We used the Hospital Anxiety and Depression Scale, the Zarit Burden scale and the Brief COPE to measure coping strategies.

Results

Using fewer emotion‐focused strategies and more problem‐focused strategies (but not dysfunctional strategies) mediated the relationship between caregiver burden and anxiety a year later, after controlling for potential confounders, in a well‐fitting structural equation model (χ2 = 0.93, df = 3, p = 0.82; NFI = 1.0, RFI = 0.97, IFI = 1.0, TLI = 1.1, RMSEA = 0.0). Using fewer emotion focused strategies also predicted higher psychological morbidity in general. The hypothesised relationship was not proved for depression.

Conclusions

Using emotion‐focussed coping strategies in response to caregiver burden seemed to protect caregivers from developing higher anxiety levels a year later; however using problem‐focussed strategies did not. Our results suggest that a psychological intervention package to emphasise emotion‐focused coping may be a rational approach to reduce anxiety in dementia caregivers. Studies are needed to test such interventions. Copyright © 2008 John Wiley & Sons, Ltd.
Abuse by marriage: the exploitation of mentally ill older people
Authors: Peisah Carmelle , Brodaty Henry , Bridger Marie
Published: March 2008

Objectives

(i) To raise awareness about the vulnerability of mentally ill older persons to abuse by others seeking to gain by marriage; (ii) to outline key legal cases from common law countries; and (iii) to provide guidelines for health care professionals who encounter this issue in practice.

Method

We present two cases: the first case involved an 87‐year‐old widower who married his carer––50 years his junior––in a religious ceremony while hypomanic. The second case involved an 82‐year‐old widow with moderate dementia who married her boarder, the marriage subsequently being found void in the Family Court of Australia on the basis that her consent was not real because she was incapable of understanding the nature and effect of the marriage ceremony.

Results

Abuse by marriage may be of a psychological, sexual, social or financial nature.

Older people with impaired judgement and inability to appraise others due to mental illness may be persuaded to execute legal documents such as marriage certificates.

Conclusion

Health care professionals may have a role in the identification and management of this kind of abuse. There are legal means to address this problem ranging from guardianship and financial management to family law court applications to seek a decree of nullity/invalidity of the marriage. Copyright © 2008 John Wiley & Sons, Ltd.
Acute myeloid leukaemia after treatment with 90Y‐ibritumomab tiuxetan for follicular lymphoma
Authors: Focosi Daniele , Cecconi Nadia , Boni Giuseppe , Orciuolo Enrico , Galimberti Sara , Petrini Mario
Published: March 2008

We report here a patient with relapsed follicular lymphoma who developed secondary acute myeloid leukaemia 15 months after radioimmunotherapy (RIT) with 90Y‐ibritumomab tiuxetan, the fifth described case to date. We review the literature for the potential causal relationship between RIT and secondary myelodysplastic syndromes/acute myeloid leukaemia. Copyright © 2008 John Wiley & Sons, Ltd.
Water use and productivity of two small reservoir irrigation schemes in Ghana's upper east region
Authors: Faulkner Joshua W. , Steenhuis Tammo , van de Giesen Nick , Andreini Marc , Liebe Jens R.
Published: March 2008

To examine the impact of small reservoir irrigation development in Africa, the performance and productivity of two small reservoirs and irrigation schemes in the Upper East Region of Ghana were investigated in this study. Hydrologic data measured included daily irrigation volumes and daily evaporation. Farmer cost inputs, excluding labor, and harvest data were also recorded. There was a strong contrast in water availability between the two systems, the Tanga system having a higher amount of available water than did the Weega system. The concept of relative water supply was used to confirm this disparity; Tanga was an inefficient system with a relative water supply of 5.7, compared to a value of 2.4 for the efficient Weega system. It was also concluded that the dissimilar water availabilities resulted in the evolution of very different irrigation methods and coincided with different management structures. Where there was more water available per unit land (Tanga), management was relaxed and the irrigation inefficient. Where there was less water available per unit land (Weega), management was well structured and irrigation efficient. The productivity of water (US$ m−3) of the Tanga system was half that of the Weega system, when analyzed at a high market price for crops grown. In terms of productivity of cultivated land (US$ ha−1), however, the Tanga system was 49% more productive than the Weega system. The difference in the productivity of land is primarily a result of increased farmer cash inputs in the Tanga system as compared to the Weega system. The difference in the productivity of water can be attributed to the varying irrigation methods and management structures, and ultimately to the contrasting water availability. Copyright © 2008 John Wiley & Sons, Ltd.
Source of low‐frequency fluctuations in functional MRI signal
Authors: Razavi Mehrdad , Eaton Brent , Paradiso Sergio , Mina Mani , Hudetz Anthony G. , Bolinger Lizann
Published: March 2008

Purpose

To investigate the source of native low‐frequency fluctuations (LFF) in functional MRI (fMRI) signal.

Materials and Methods

Phase analysis was performed on tissue‐segmented fMRI data acquired at systematically varying sampling rates.

Results

LFF in fMRI signal were both native and aliased in origin. Scanner instability did not contribute to native or aliased LFF. Aliased LFF arose from cardiorespiratory processes and head motion. Native LFF did not arise from cardiorespiratory processes, but did so, at least in part, from head motion. Motion correction reduced native LFF, but did not eliminate them. The residual native LFF in motion‐corrected fMRI data showed a systematic phase difference among different tissue structures. The native LFF in fMRI signals of cerebral blood vessels and CSF were synchronous, and preceded those of gray and white matter, indicating that the vascular fluctuations lead the metabolic fluctuations.

Conclusion

The primary physiologic source of native LFF in fMRI signal is vasomotion. J. Magn. Reson. Imaging 2008;27:891–897. © 2008 Wiley‐Liss, Inc.
Relationship between choline and apparent diffusion coefficient in patients with gliomas
Authors: Khayal Inas S. , Crawford Forrest W. , Saraswathy Suja , Lamborn Kathleen R. , Chang Susan M. , Cha Soonmee , McKnight Tracy R. , Nelson Sarah J.
Published: March 2008

Purpose

To examine the relationship between apparent diffusion coefficients (ADC) from diffusion weighted imaging (DWI) and choline levels from proton magnetic resonance spectroscopic imaging (MRSI) in newly diagnosed Grade II and IV gliomas within distinct anatomic regions.

Materials and Methods

A total of 37 patients with Grade II and 28 patients with Grade IV glioma were scanned on a 1.5T system with 3D MRSI and DWI. Region level analysis included Spearman rank correlation between median normalized ADC and choline for each patient per grade within each distinct abnormal anatomical region. Voxel level analysis calculated a Spearman rank correlation per region, per patient.

Results

Grade II lesions showed no evidence of a correlation between normalized ADC and choline using either the region or voxel level analysis. Region level analysis of Grade IV lesions did not appear to correlate in the contrast enhancement or necrotic core, but did suggest a significant negative correlation in the more heterogeneous nonenhancing and combined regions.

Conclusion

There appears to be differences in the relationship between ADC and choline levels in Grade II and Grade IV gliomas. Correlation within these regions in Grade IV lesions was strongest when all regions were included, suggesting heterogeneity may be driving the relationship. J. Magn. Reson. Imaging 2008;27:718–725. © 2008 Wiley‐Liss, Inc.
Contrast‐enhanced MRI of murine sponge model for progressive angiogenesis assessed with gadoteridol (ProHance) and gadocoletic acid trisodium salt (B22956/1)
Authors: Ramponi Simona , Rebaudengo Cristina , Cabella Claudia , Grotti Adriana , Vultaggio Stefania , Aime Silvio , Morisetti Alberto , Lorusso Vito
Published: March 2008

Purpose

To investigate the potential value of MRI for noninvasive assessment of angiogenesis in a murine model exploiting the properties of two contrast agents, gadoteridol (ProHance) and gadocoletic acid trisodium salt (B22956/1).

Materials and Methods

Biocompatible sponges were implanted in both mice flanks. Stimulated sponges contained human recombinant basic fibroblast growth factor (bFGF) as the angiogenic agent; control sponges contained vehicle. Angiogenesis was evaluated by MRI after injection of extravascular (ProHance) or blood‐pool (B22956/1) contrast agents at different times after sponge implantation. Sponges signal intensity enhancement was calculated both as the relative enhancement and the rate of relative enhancement. Results from MRI were validated by classic biochemical (hemoglobin level and protein content) and morphological (histology) assays.

Results

The intrinsic different properties of ProHance and B22956/1 in wash‐in and wash‐out kinetics were useful to detect progressive vascularization and the establishment of a functional vascular network in the implants. Moreover, MRI allowed the appreciation of differences in neovessel colonization between bFGF‐treated sponges and controls. Hemoglobin level, protein content, and histology confirmed the sponge vascularization and MRI results.

Conclusion

Contrast‐enhanced MRI is a reliable tool to study vascular characteristics in animal models of angiogenesis. The different kinetic properties of contrast agents can provide evidence of different functional neovascularization aspects and levels. J. Magn. Reson. Imaging 2008;27:872–880. © 2008 Wiley‐Liss, Inc.
Simultaneous imaging of myocardial motion and chamber blood flow with SPAMM n' EGGS (spatial modulation of magnetization with encoded gradients for gauging speed)
Authors: Sampath Smita , Kim June H. , Lederman Robert J. , McVeigh Elliot R.
Published: March 2008

Purpose

To provide simultaneous measurements of one‐dimensional (1‐D) myocardial displacement and 1‐D chamber blood flow in a single breath‐held acquisition using an MR imaging technique, SPAMM n' EGGS (Spatial Modulation of Magnetization With Encoded Gradients for Gauging Speed).

Materials and Methods

Velocity encoding bipolar gradients sensitive to chamber blood flow were played out before the readout gradient in a 1‐1 SPAMM‐tagged MR imaging pulse sequence. For any given motion–flow encoded direction, the acquired image sequence was later postprocessed to separate the tag motion and blood flow terms. Experiments were performed on seven normal volunteers, and two pigs with moderate ischemic mitral regurgitation. Left‐ventricular motion and trans‐valvular flow obtained using the SPAMM n' EGGS pulse sequence was compared against measurements obtained using standard tagging and phase‐contrast pulse sequences, respectively.

Results

Results in normal volunteers and diseased pigs demonstrate multiphase correlated measurements of myocardial motion and chamber blood flow using SPAMM n' EGGS. A close correspondence in these measurements to conventional tagging and phase‐contrast sequences is confirmed.

Conclusion

We have demonstrated that simultaneous acquisition of myocardial motion and chamber blood flow is possible within a single breath‐hold. The data obtained using the SPAMM n' EGGS pulse sequence may be useful in the planning and evaluation of mitral‐valve repair procedures. J. Magn. Reson. Imaging 2008;27:809–817. © 2008 Wiley‐Liss, Inc.
Quantification of MRI measured myocardial perfusion reserve in healthy humans: A comparison with positron emission tomography
Authors: Fritz‐Hansen Thomas , Hove Jens D. , Kofoed Klaus F. , Kelbaek Henning , Larsson Henrik B.W.
Published: March 2008

Purpose

To validate a noninvasive quantitative MRI technique, the Ki perfusion method, for myocardial perfusion in humans using 13N‐ammonia PET as a reference method.

Materials and Methods

Ten healthy males (64 ± 8 years) were examined with combined PET and MRI perfusion imaging at rest and during stress induced by dipyridamole in order to determine the myocardial perfusion reserve. Myocardial and blood time concentration curves obtained by Gd‐DTPA‐enhanced MRI and 13N‐ammonia PET were fitted by a two‐compartment perfusion model.

Results

Mean perfusion values (±SD) derived from the MRI method at rest and at hyperemia were 80 ± 20 and 183 ± 56 mL/min/100 g, respectively. The same data for PET were 71 ± 16 and 203 ± 67 mL/min/100 g. A linear relationship was observed between MRI and PET‐derived myocardial perfusion reserve for regional and global data. Linear regression for the global absolute perfusion reserve gave a correlation coefficient of 0.96 (P < 0.004, y=0.83x‐6.9). A good agreement between the two methods to determine low or high perfusion reserves was found.

Conclusion

Our data provide validation of the perfusion marker Ki derived by the MRI method as a quantitative marker for myocardial perfusion in healthy humans. J. Magn. Reson. Imaging 2008;27:818–824. © 2008 Wiley‐Liss, Inc.
Local re‐inversion coronary MR angiography: Arterial spin‐labeling without the need for subtraction
Authors: Katoh Marcus , Spuentrup Elmar , Barmet Christoph , Stuber Matthias
Published: March 2008

Purpose

To implement a double‐inversion bright‐blood coronary MR angiography sequence using a cylindrical re‐inversion prepulse for selective visualization of the coronary arteries.

Materials and Methods

Local re‐inversion bright‐blood magnetization preparation was implemented using a nonselective inversion followed by a cylindrical aortic re‐inversion prepulse. After an inversion delay that allows for in‐flow of the labeled blood‐pool into the coronary arteries, three‐dimensional radial steady‐state free‐precession (SSFP) imaging (repetition/echo time, 7.2/3.6 ms; flip angle, 120°, 16 profiles per RR interval; field of view, 360 mm; matrix, 512, twelve 3‐mm slices) is performed. Coronary MR angiography was performed in three healthy volunteers and in one patient on a commercial 1.5 Tesla whole‐body MR System.

Results

In all subjects, coronary arteries were selectively visualized with positive contrast. In addition, a middle‐grade stenosis of the proximal right coronary artery was seen in one patient.

Conclusion

A novel T1 contrast‐enhancement strategy is presented for selective visualization of the coronary arteries without extrinsic contrast medium application. In comparison to former arterial spin‐labeling schemes, the proposed magnetization preparation obviates the need for a second data set and subtraction. J. Magn. Reson. Imaging 2008;27:913–917. © 2008 Wiley‐Liss, Inc.
Estrogen receptor and breast MR imaging features: A correlation study
Authors: Chen Jeon‐Hor , Baek Hyeon‐Man , Nalcioglu Orhan , Su Min‐Ying
Published: March 2008

Purpose

To compare the MRI features between estrogen receptor (ER) positive and negative breast cancers.

Materials and Methods

Breast MRI of 90 consecutive patients confirmed with invasive ductal carcinoma (IDC), 51 ER positive and 39 ER negative, were analyzed. The tumor morphology and dynamic contrast‐enhanced (DCE) kinetics were evaluated based on the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI‐RADS) MRI lexicon and compared. Enlarged axillary lymph nodes on MRI and choline (Cho) detection using MR spectroscopy (MRS) were also analyzed and compared. For patients receiving axillary node dissection the pathological nodal status was also compared.

Results

ER negative breast cancer had bigger tumors compared to ER positive cancer (3.6 ± 2.0 cm vs. 1.8 ± 1.3 cm, P < 0.00005). ER negative cancer was more likely to exhibit nonmass type enhancements compared to ER positive cancer (P < 0.005). Enlarged axillary lymph nodes were more frequently identified on MRI in ER negative compared to ER positive patients (P < 0.05). After excluding patients undergoing neoadjuvant chemotherapy, axiliary lymph node status did not show significant difference between ER positive and ER negative cancer on MRI and pathology. ER negative cancer was more likely to show the malignant type enhancement kinetics (P = 0.15), rim enhancement (P = 0.15), and Cho detection on MRS (P = 0.23) compared to ER positive cancer, but it did not reach a level of statistical significance.

Conclusion

ER negative breast cancer was more aggressive, with larger tumor size, more non‐mass‐type enhancement lesions, and a higher percentage showing enlarged axillary nodes on MRI. These features might be related to its poorer cellular differentiation and/or a higher angiogenesis. J. Magn. Reson. Imaging 2008;27:825–833. © 2008 Wiley‐Liss, Inc.
Liquid and gas chromatography coupled to isotope ratio mass spectrometry for the determination of 13C–valine isotopic ratios in complex biological samples
Authors: Godin Jean‐Philippe , Breuillé Denis , Obled Christiane , Papet Isabelle , Schierbeek Henk , Hopfgartner Gérard , Fay Laurent‐Bernard
Published: March 2008

On‐line gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS) is commonly used to measure isotopic ratios at natural abundance as well as for tracer studies in nutritional and medical research. However, high‐precision 13C isotopic enrichment can also be measured by liquid chromatography‐isotope ratio mass spectrometry (LC‐IRMS). Indeed, LC‐IRMS can be used, as shown by the new method reported here, to obtain a baseline separation and to measure 13C isotopic enrichment of underivatised amino acids (Asp, Thr–Ser, Glu, Pro, Gly, Ala, Cys and Val). In case of Val, at natural abundance, the SD(δ13C) reported with this method was found to be below 1‰ . Another key feature of the new LC‐IRMS method reported in this paper is the comparison of the LC‐IRMS approach with the conventional GC‐C‐IRMS determination. To perform this comparative study, isotopic enrichments were measured from underivatised Val and its N(O, S)‐ethoxycarbonyl ethyl ester derivative. Between 0.0 and 1.0 molar percent excess (MPE) (δ13C = − 12.3 to 150.8‰), the calculated root‐mean‐square (rms) of SD was 0.38 and 0.46‰ and the calculated rms of accuracy was 0.023 and 0.005 MPE, respectively, for GC‐C‐IRMS and LC‐IRMS. Both systems measured accurately low isotopic enrichments (0.002 atom percent excess (APE)) with an SD (APE) of 0.0004. To correlate the relative (δ13C) and absolute (atom%, APE and MPE) isotopic enrichment of Val measured by the GC‐C‐IRMS and LC‐IRMS devices, mathematical equations showing the slope and intercept of the curves were established and validated with experimental data between 0.0 to 2.3 MPE. Finally, both GC‐C‐IRMS and LC‐IRMS instruments were also used to assess isotopic enrichment of protein‐bound 13C–Val in tibial epiphysis in a tracer study performed in rats. Isotopic enrichments measured by LC‐IRMS and GC‐C‐IRMS were not statistically different (p > 0.05). The results of this work indicate that the LC‐IRMS was successful for high‐precision 13C isotopic measurements in tracer studies giving 13C isotopic enrichment similar to the GC‐C‐IRMS but without the step of GC derivatisation. Therefore, for clinical studies requiring high‐precision isotopic measurement, the LC‐IRMS is the method of choice to measure the isotopic ratio. Copyright © 2008 John Wiley & Sons, Ltd.
Mycoflora associated withHyoscyamus muticusgrowing under an extremely arid desert environment (Aswan region, Egypt)
Authors: El‐Zayat Soad A. , Nassar Mortada S. M. , El‐Hissy Farida T. , Abdel‐Motaal Fatma F. , Ito Shin‐ichi
Published: March 2008

Hyoscyamus muticusL. (Egyptian henbane) is one of the desert medicinal plants of family Solanaceae. The plant produces pharmaceutically important compounds (tropane alkaloids) as secondary metabolites. In the present study, we describe mycoflora ofH. muticusgrown in four different locations in Egyptian southern desert (Aswan region): Aswan university campus, Wadi Allaqi down stream part, Aswan airport road, and Sahari city. Eighty‐one species and two varieties belonging to 31 genera were isolated from soils surroundingH. muticusplants, the surface of the plants, and inside the plants as endophytic fungi.Aspergilluswas the most common genus in all study areas. The highest number of genera and species of fungi were recorded in Aswan university campus followed by Aswan airport road. Fungal diversity analysis revealed that these two locations have higher fungal diversity compared to other two locations. A higher number of fungal species were isolated from rhizosphere soil and rhizoplane than from non‐rhizosphere and other plant organs. Endophytic fungi were isolated from all plant parts ofH. muticus.Communications betweenH. muticusplants and fungi under desert conditions both in rhizosphere and inside the plant are deduced. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Screening of Aspergillus species for occurrence of lectins and their characterization
Authors: Singh Ram Sarup , Tiwary Ashok Kumar , Bhari Ranjeeta
Published: March 2008

Ten species of Aspergillus were screened for occurrence of lectins. Each of the species was investigated for the occurrence of extracellular, surface‐bound and intracellular lectin activities. As many as four species namely, Aspergillus niger, Aspergillus versicolor, Aspergillus rugulosus and Aspergillus nidulans, were found to possess intracellular lectin activities, while none of the species showed extracellular or surface‐bound lectin activities. Each of the lectin was characterized with respect to blood group and carbohydrate specificities. All the lectins were found to agglutinate human erythrocytes, irrespective of their blood group and pig erythrocytes. However, they did not show agglutination with sheep or goat erythrocytes. Of the various carbohydrates tested, all lectins were found to be specific for inulin, mucin, asialofetuin, N‐acetyl galactosamine, melibiose, D‐ribose, L‐fucose, D‐arabinose, D‐sucrose and D‐mannitol. The minimum inhibitory concentration of each of the specific sugars was also determined. The lectins were partially purified using ammonium sulfate precipitation technique. Each of the lectin was found to be precipitated at 40–50% saturation of ammonium sulfate, yielding about 80% of lectin activity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new spiroketal from Aspergillus terreus, an endophytic fungus in Opuntia ficusindica Mill
Authors: Wu Shao‐Hua , Chen You‐Wei , Qin Sheng , Huang Rong
Published: March 2008

A new spiroketal, named aspergiketal (1) was isolated from the culture broth of Aspergillus terreus, an endophytic fungus in the stems of the plant Opuntia ficusindica Mill., together with two known compounds, physcion (2) and asterric acid (3). Their structures were elucidated by spectroscopic methods including 2D‐NMR techniques. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Supercritical fluid extraction of cynaropicrin and 20‐hydroxyecdysone from Leuzea carthamoides DC
Authors: Sovová Helena , Opletal Lubomír , Sajfrtová Marie , Bártlová Milena
Published: March 2008

Leuzea carthamoides is an adaptogenic plant containing biologically active compounds as ecdysteroids and guaianolide‐type sesquiterpene lactones, conventionally extracted from the plant with ethanol. It may be a potential source of the mentioned natural compounds. Ethanol‐modified near‐critical CO2 was used as selective solvent with the aim to increase the level of 20‐hydroxyecdysone in the extract from L. carthamoides roots and to remove selectively cynaropicrin, a sesquiterpene lactone of bitter taste, from the leaves. The extraction conditions were varied (pressure 20–28 MPa, temperature 40–60°C, ethanol concentration in the solvent 0–7.1%) and the extraction yield and extract composition were compared with the results of ethanolic extraction. The supercritical fluid extraction (SFE) from finely powdered plant was controlled by phase equilibrium. Cynaropicrin was quantitatively removed from the leaves where 89% of 20‐hydroxyecdysone was retained. The extraction yield of 20‐hydroxyecdysone from roots with ethanol‐modified CO2 was lower by 30% than with ethanol but its concentration in the extract was higher by 67%.
Light propagation in multi‐step index optical fibres
Authors: Zubia J. , Aldabaldetreku G. , Durana G. , Arrue J. , Jiménez F.
Published: March 2008

This paper reviews the theoretical analysis of light propagation we have carried out on multimode multi‐step index (MSI) optical fibres. Starting from the Eikonal equation, we derive the analytical expressions that allow calculating the ray trajectories inside these fibres. We also analyse the effects of leaky rays on the transmission properties of MSI fibres. For this purpose, a single analytical expression for the evaluation of the ray power transmission coefficient is calculated. Afterwards, we investigate the effects of extrinsic and intrinsic coupling losses on the performance of MSI fibres, providing analytical expressions to calculate the coupling loss and, also, determining the most critical parameters. Finally, we carry out a comprehensive numerical analysis of the fibre bandwidth under different source configurations.
Potential and limitations of laser technology in restoration of metallic objects of art and cultural heritage
Authors: Klotzbach U. , Panzner M. , Wiedemann G.
Published: March 2008

Potential applications of laser techniques, such as precision cutting, micro welding, and ablation of stains, are presented. Concerning laser beam ablation, we explain the mechanism, and then discuss potential applications (cleaning of gilded or solid metal surfaces, cleaning of verdigris) and limits (thinning of verdigris, removing rust from verdigris). This research has been performed within the frame of a joint project sponsored by Deutsche Bundesstiftung Umwelt (DBU, German Foundation for the Environment) as well as in immediate co‐operation with restorers. The presentation of these results is to propose laser technology as a promising option to be taken into account in planning and doing restoratory work.
The conservation of iron objects in archaeological preservation – Application and further development of alkaline sulphite method for conservation of large quantities of iron finds
Authors: Schmutzler B. , Ebinger‐Rist N.
Published: March 2008

The usual damage on archaeological iron finds caused by corrosion are outlined in this paper. For a better understanding of these phenomena and the resulting consequences for iron conservation a short literature summary is given regarding actual corrosion models for archaeological iron finds. The desalination of chloride‐contaminated iron finds is the demand to be derived from this synopsis. Therefore, the desalination with the alkaline sulphite reduction method is applied at Landesamt für Denkmalpflege Baden‐Württemberg recently, which allows the long‐term stabilization of many iron finds. Finally, the research project ‘Investigations into the alkaline sulphite treatment for conservation of large quantities of archaeological iron objects’ is introduced.
Transparente Beschichtungsstoffe zum Schutz von Kulturgütern Use of transparent coating systems for the protection of culture heritage
Authors: Conrads M.
Published: March 2008

Zusammenfassung: Der Schutz von technischen Kulturgütern macht den Einsatz transparenter Beschichtungsstoffe erforderlich um beispielsweise sog. Gebrauchsspuren und die damit verbundene Darstellung der Nutzung von Objekten zu erhalten.

Die Dauerhaftigkeit transparenter Beschichtungsstoffe ist deutlich geringer als mit pigmentierten Systemen.

Dieser Beitrag beschäftigt sich mit ersten Versuchen, die Unterschiede von verschiedenen transparenten Systemen wie Lacke, Wachse, Fette und Öle im Hinblick auf ihre Schutzwirkung zu ermitteln und aufzuzeigen.

Die besten Ergebnisse zeigten bisher die Polyurethanlacke sowie die Ormocere.

Summary: The protection of technical cultural heritage needs transparent coating systems to demonstrate e.g. marks of use and the herewith connected demonstration of the use of objects.

The period of protection from transparent coating systems is much more shorter than with pigmented coloured paints.

This article informs about first trials with different transparent coating systems like paints, waxes, fats and oils and shows the differences in their suitability for corrosion protection.

The best results up to now show the polyurethane systems and the Ormoceres.
Poly(amide‐imides): Wire Enamels with Excellent Thermal and Chemical Properties
Authors: Murray Thomas J.
Published: March 2008

Poly(amide‐imide) resins are versatile high‐performance polymers used as primary electrical insulation. They can be synthesized by three well‐established methods, of which only two are commercially exploited. Outstanding characteristics include high thermal performance, chemical and abrasion resistance, and low coefficient of friction. Other industries also rely on these same properties for use as coatings, extrusion resins and films. Recent developments are discussed and future trends/product offerings are reviewed. Developments include corona‐resistant enamels, self‐lubricated and high‐abrasion‐resistance coatings. The hybrid automobile industry offers opportunities for further innovations in primary electrical coatings.

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Polymer Crystallization: A DSC Approach to Building the T‐CR‐T Diagram
Authors: Berlanga Rosa , Suñol Joan J. , Saurina Joan
Published: March 2008

T‐CR‐T diagrams are one of the most reliable ways to predict the thermal behavior of material solidification from the melt. A brief description of solidification accounting for continuous cooling is presented for fast‐crystallizing polymers. An isoconversional method is applied to the kinetic analysis of non‐isothermal processes. The solidification process of different polymer materials: high density polyethylene based samples and mixtures of PEG with a pharmaceutical drug were analyzed by means of DSC. Several diagrams were constructed and the best agreement between experimental data and the calculated T‐CR‐T curves corresponds to the use of the isoconversional method.

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Alternative approach for modeling material interfaces in FDTD
Authors: Laakso Ilkka , Uusitupa Tero
Published: March 2008

A simple alternative way to position dielectric materials in the finite‐difference time‐domain (FDTD) Yee cell grid is proposed. Plane‐wave illuminated spheres are used as examples to study the performance of the alternative method compared to the standard FDTD method. Although the performances are generally equally good, the alternative method may sometimes give significantly improved accuracy. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1211–1214, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23309
PMD mitigation and wavelength conversion using a SOA‐based interferometric switch
Authors: Jianping Wang
Published: March 2008

We propose a new application of the SOA‐based wavelength conversion, which can realize polarization mode dispersion (PMD) mitigation for 10 GHz picosecond optical pulse. Both PMD mitigation and wavelength conversion are demonstrated by experiments. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1171–1173, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23312
Velocity compensated coplanar wave guide bend for odd‐mode suppression
Authors: Hong Wang Jun , Zhang Hui
Published: March 2008

A kind of velocity compensated coplanar wave guide (CPW) bend is proposed, in which one slot of CPW bend with shorter length is corrugated, so that the signal propagating in this slot is slowed down, and the signal propagating in the longer slot can catch up with the signal in the shorter slot. Both simulated and experimental results show that the odd mode can be suppressed efficiently by this kind of CPW bend, and the properties of reflection and transmission are improved significantly, especially in high‐frequency band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1201–1204, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23315
Adaptive neuro‐fuzzy models for the quasi‐static analysis of microstrip line
Authors: Yildiz Celal , Guney Kerim , Turkmen Mustafa , Kaya Sabri
Published: March 2008

This article presents a new method based on adaptive neuro‐fuzzy inference system (ANFIS) to calculate the effective permittivities and characteristic impedances of microstrip lines. The ANFIS is a fuzzy inference system (FIS) implemented in the framework of an adaptive fuzzy neural network. It has the advantages of expert knowledge of FISs and learning capability of artificial neural networks. A hybrid learning algorithm, which combines the least square method and the back propagation algorithm, is used to identify the parameters of ANFIS. The results of ANFIS are compared with the results of the experimental works, quasi‐static methods, and a commercial electromagnetic simulator IE3D. There is very good agreement among the results of ANFIS models and quasi‐static methods, IE3D, and experimental works. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1191–1196, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23322
On‐chip slot antennas in 0.18 μm CMOS for wireless application
Authors: Jiang Liang , Yin Wen‐Yan , Mao Junfa
Published: March 2008

Two on‐chip slot antennas resonating near 30 GHz with different widths (10 and 100 μm) in standard 0.18 μm CMOS are presented. S21 between two 10 μm width slot antennas and between two 100 μm width ones both with ∼3 mm distance through free space is measured. The results indicate that designing on‐chip slot antennas with standard CMOS process is feasible, which will support farther improvement of CMOS integration. The slot antennas can be used in compact and low cost transceivers for short range wireless communications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1187–1191, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23325