bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene expression in the efferent ducts, epididymis, and vas deferens during embryonic development of the mouse
Authors: Snyder Elizabeth M. , Small Christopher L. , Bomgardner Daniela , Xu Bingfang , Evanoff Ryan , Griswold Michael D. , Hinton Barry T.
Published: July 2010

The tissues of the male reproductive tract are characterized by distinct morphologies, from highly coiled to un‐coiled. Global gene expression profiles of efferent ducts, epididymis, and vas deferens were generated from embryonic day 14.5 to postnatal day 1 as tissue‐specific morphologies emerge. Expression of homeobox genes, potential mediators of tissue‐specific morphological development, was assessed. Twenty homeobox genes were identified as either tissue‐enriched, developmentally regulated, or both. Additionally, ontology analysis demonstrated cell adhesion to be highly regulated along the length of the reproductive tract. Regulators of cell adhesion with variable expression between the three tissues were identified including Alcam, various cadherins, and multiple integrins. Immunofluorescence localization of the cell adhesion regulators POSTN and CDH2 demonstrated cell adhesion in the epithelium and mesenchyme of the epididymis may change throughout development. These results suggest cell adhesion may be modulated in a tissue‐specific manner, playing an important role in establishing each tissue's final morphology. Developmental Dynamics 239:2479–2491, 2010. © 2010 Wiley‐Liss, Inc.
Transient stability output margin estimation based on the energy function method
Authors: Miwa Natsuki , Tanaka Kazuyuki
Published: July 2010

In this paper, a new method of estimating the critical generation margin (CGM) in power systems is proposed based on transient stability diagnostics. The proposed method can directly compute the stability limit output for a given fault based on the transient energy function method (TEF). Since CGM can be directly obtained by the limit output using estimated P‐θ curves and is easy to understand, it is more useful than the conventional critical clearing time (CCT) of the energy function method. The proposed method can also estimate CGM as a negative value, which means instability in the present load profile, and so a negative CGM can be directly used as a restriction on generator output.

The accuracy and fast solution ability of the proposed method are verified by applying it to a simple 3‐machine model and IEEJ EAST10‐machine standard model. Furthermore, the usefulness of the method for severity ranking of transient stability for various fault cases is discussed by using CGM. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(3): 10–19, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ eej.21035
Prussian Blue‐Modified Titanate Nanotubes: A Novel Nanostructured Catalyst for Electrochemical Reduction of Hydrogen Peroxide
Authors: Iveković Damir , Gajović Andreja , Čeh Miran , Pihlar Boris
Published: July 2010

Prussian blue (PB) modified titanate nanotubes (PB‐TiNT) have been synthesized by the reaction of Fe2+‐modified TiNT with hexacyanoferrate(III) ions. The rate constant for heterogeneous catalytic reaction between PB‐TiNT and H2O2 was found to be k=2×104 dm3 mol−1 s−1, which is an order of magnitude higher than the values of k reported for conventionally prepared, electrochemically deposited PB films. On the PB‐TiNT modified electrode with subnanomolar surface concentration of PB (Γ(PB)=2.8×10−11 mol/cm2), a stable, reproducible and linear response towards H2O2 was obtained in the concentration range 0.02–4 mM, with the sensitivity of 0.10 AM−1 cm−2 at −150 mV.
Poly(pyridine‐3‐boronic acid)/Multiwalled Carbon Nanotubes Modified Glassy Carbon Electrodes for Simultaneous Determination of Ascorbic Acid, 3,4‐Dihydroxyphenylacetic Acid and Uric Acid
Authors: Wu Zhijiao , Zhao Hong , Xue Ying , He Yujian , Li Xiangjun , Yuan Zhuobin
Published: July 2010

Poly(pyridine‐3‐boronic acid) (PPBA)/multiwalled carbon nanotubes (MWCNTs) composite modified glassy carbon electrode (GCE) was used for the simultaneous determination of ascorbic acid (AA), 3,4‐dihydroxyphenylacetic acid (DOPAC) and uric acid (UA). The anodic peaks for AA, DOPAC and UA at the PPBA/MWCNTs/GCE were well resolved in phosphate buffer solution (pH 7.4). The electrooxidation of AA, DOPAC and UA in the mixture solution was investigated. The peak currents increase with their concentrations increasing. The detection limits (S/N=3) of AA, DOPAC and UA are 5 µM, 3 µM and 0.6 µM, respectively.
Critical Effect of Polyelectrolytes on the Electrochemical Response of Dehydrogenases Entrapped in Sol‐Gel Thin Films
Authors: Wang Zhijie , Etienne Mathieu , Kohring Gert W. , Walcarius Alain
Published: July 2010

The influence of polyelectrolyte (PE) additives on the sol‐gel encapsulation of dehydrogenases has been evaluated using D‐sorbitol dehydrogenase (DSDH) as a model enzyme. Thin sol‐gel films were prepared on glassy carbon electrodes (GCE), which were then evaluated with respect to the electrochemical detection of D ‐sorbitol. DSDH encapsulation in pure silica thin films resulted in undetectable electrochemical signal. Adding positively‐charged PE that contributes to stabilize the negatively‐charged DSDH in the biocomposite film led to much faster and higher response of DSDH to its substrate, as shown by the significant improvement in bioelectrochemical detection of NADH produced during the oxidation of D‐sorbitol.
Quantitative Structure–Electrochemistry Relationship of 1‐Phenyl‐5‐benzyl‐sulfanyltetrazoles and Their Electrooxidation as a Metabolic Model
Authors: Nesměrák Karel , Doležal Rafael , Hudská Věra , Bártl Josef , Štícha Martin , Waisser Karel
Published: July 2010

The quantitative structure‐electrochemistry relationships study of nineteen derivatives of 1‐phenyl‐5‐benzylsulfanyltetrazole, that seem to be very promising antimycobacterial drugs, resulted in a good correlation relationship between half‐wave potential and energy of HOMO orbital. The study of electrochemical oxidation of these compounds as a model of their possible metabolic degradation was performed. It was possible to propose a scheme of their electrochemical oxidation: the electrochemical oxidation starts on the methoxy group, where by elimination of one electron the radical cation with very short life‐time is formed. The free electron is translocated to the position 2, followed by closing of new cycle with CH2 of benzylsulfanyl moiety. In the case of 2‐methoxyphenyl tetrazoles this process is followed by the desintegration of the tetrazole ring.
Glucose Biosensor Based on Silicon Nitride Nanoparticles
Authors: Salimi Abdollah , Zand‐Karimi Roaya , Noorbakhash Abdollah , Soltanian Saied
Published: July 2010

For the first time silicon nitride (Si3N4) nanoparticles was used for preparation electrochemical biosensor. GOx immobilized on the Si3N4 nanoparticles exhibits facile and direct electrochemistry. The surface coverage and heterogeneous electron transfer rate constant (ks) of immobilized GOx were 6.3×10−13 mol cm−2 and 47.4±0.3 s−1. The sensitivity, linear concentration range and detection limit of the biosensor for glucose detection were 38.57 µA mM−1 cm−2, 25 µM to 8 mM and 6.5 µM, respectively. This biosensor also exhibits good stability, reproducibility and long life time. These indicate Si3N4 nanoparticles is good candidate material for construction of third generation biosensor and bioelectronics devices.
Biparametric Potentiometric Analytical Microsystem Based on the Green Tape Technology
Authors: Ibáñez‐García Nuria , Baeza Mireia , Puyol Mar , Gómez Raquel , Batlle Montse , Alonso‐Chamarro Julian
Published: July 2010

The construction and evaluation of a Low Temperature Co‐fired Ceramics (LTCC)‐based microsystem prototype as a possible on‐site microanalyzer to monitor the presence of two ions in water simultaneously is presented. The approach has been assayed to detect nitrate and chloride ions as model analytes by means of integrating in the same single substrate an ion selective polymeric membrane to nitrate and two screen‐printed Ag/AgCl electrodes. One supplies the chloride ion concentration and the other is to complete the potentiometric detection system as the reference electrode. The results obtained by the full characterization of the microanalyzer prove the relevance of the proposal and the possibility to be transferred to real‐world samples and environmental monitoring.
A Diverse‐Stimuli Responsive Chemiluminescent Probe with Luminol Scaffold and Its Electropolymerization
Authors: Asil Demet , Cihaner Atilla , Algı Fatih , Önal Ahmet M.
Published: July 2010

A diverse‐stimuli responsive chemiluminescent system, SNS‐Lum, and its electropolymerization to give PSNS‐Lum, which is the first example of conjugated polymers with pendant luminol arms inducing chemiluminescence in the presence of super oxide radical anion under neutral conditions, are highlighted.
Rapid Automatic Determination of Calcium and Magnesium in Aqueous Solutions by FIA Using Potentiometric Detection
Authors: Vahl Katja , Kahlert Heike , Scholz Fritz
Published: July 2010

A pH‐sensitive detector for flow‐through potentiometry based on a graphite/quinhydrone/silicone composite electrode was applied to determine calcium and magnesium in aqueous solutions. The determinations are performed by FIA titrations with EDTA as the carrier solution. The method was applied to the analysis of mineral water, drinking water, and river water. The results were compared with those obtained by batch complexometric titration. The proposed new method is suitable for the simple, rapid and automated determination of water hardness in small sample volumes of aqueous solutions. The detection limit for both ions is about 1×10−5 mol L−1, the standard deviation is less than 2%. The sampling frequency is 60 determinations per hour.
Direct Determination of Copper in Biodiesel Using Stripping Analysis
Authors: Almeida Eduardo S. , Monteiro Marina A. N. A. , Montes Rodrigo H. O. , Mosquetta Rafael , Coelho Nívia M. M. , Richter Eduardo M. , Muñoz Rodrigo A. A.
Published: July 2010

A simple, effective, and low‐cost protocol for copper determination in biodiesel, with no sample decomposition, is reported. Samples were diluted in an ethanol‐water solution (with HCl as supporting electrolyte) generating a homogeneous mixture at which copper was directly detected using stripping chronopotentiometry using a gold working‐electrode. The optimized mixture was 100 µL (0.088 g) of biodiesel, 15 mL of ethanol, and 5 mL of 0.1 mol L−1 HCl aqueous solution. The estimated detection limit was 200 ng g−1 (300‐s deposition time). The elimination of the sample treatment step offers the possibility of on‐site measurements in association with commercially‐available portable potentiostats.
Adsorptive Stripping Determination of Scandium(III) with Mordant Blue 9 on Silver Amalgam Film Electrode
Authors: Piech Robert
Published: July 2010

A new adsorptive stripping voltammetric method for the determination of trace scandium(III) based on the adsorption of scandium(III)‐mordant blue 9 complex on the cyclic renewable mercury film silver based electrode (Hg(Ag)FE) is presented. The effects of various factors such as: preconcentration potential and time, pulse height, step potential and supporting electrolyte composition are optimized. The calibration graph is linear from 2 nM (0.09 μg L−1) to 90 nM (4 μg L−1) for a preconcentration time of 45 s, with correlation coefficient of 0.9995. For a Hg(Ag)FE with a surface area of 7.9 mm2 the detection limit for a preconcentration time of 90 s is as low as 5 ng L−1. The repeatability of the method at a concentration level of the analyte as low as 0.2 μg L−1, expressed as RSD is 1.9 % (n=5). The proposed method was successfully applied and validated by studying the certified reference material (CRM 320 – river sediment) and natural samples with simultaneous recovery of Sc(III) from spiked water and sediment samples.
Captopril Electrochemical Oxidation on Fluorine‐Doped SnO2 Electrodes and Their Determination in Pharmaceutical Preparations
Authors: Armijo Francisco , Torres Ignacio , Tapia Ricardo , Molero Leonard , Antilén Mónica , del Río Rodrigo , del Valle Mª Angélica , Ramírez Galo
Published: July 2010

A novel application of fluorine‐doped tin oxide (FTO) electrodes is reported in the present work. To this end, the captopril electrochemical oxidation mechanism on FTO electrodes at various pH and its determination in pharmaceutical preparations was investigated. Captopril oxidation on FTO proceeds at pH between 2.0 and 4.0. The study revealed that interferences for captopril determination in pharmaceutical samples was totally suppressed using these electrode materials. Voltammetric survey showed an anodic peak at about 0.375 V (Ag|AgCl) for captopril oxidation, that takes place through an EC process at pH interval 2.0–4.0. The investigation demonstrated that captopril oxidation occurs through protonated species and these electroactive species interact by adsorption on FTO electrodes, with a large heterogeneous rate constant and a mechanism involving 1H+/1e− in the global reaction. Moreover, a captopril sensor based upon FTO electrodes, with a linear range miliMolar, is proposed. These electrodes are promising candidates for the efficient electrochemical determination of captopril in pharmaceutical preparations.
Contrast‐enhanced 18F‐FDG‐PET/CT for the assessment of necrotic lymph node metastases
Authors: Haerle Stephan K. , Strobel Klaus , Ahmad Nader , Soltermann Alex , Schmid Daniel T. , Stoeckli Sandro J.
Published: July 2010

Background.

Cystic lymph node metastasis (CLNM) is commonly found in human papillomavirus (HPV)‐associated tonsillar squamous cell carcinoma (SCC). The aim of this study was to compare the accuracy in detecting cystic lymph node metastasis from tonsillar SCC between contrast‐enhanced CT, 18F‐ fluorodeoxyglucose‐positron emission tomography (FDG‐PET), non‐enhanced 18F‐FDG‐PET/CT, and contrast‐enhanced 18F‐FDG‐PET/CT.

Methods.

Thirty‐four patients with a tonsillar SCC undergoing a pretreatment contrast‐enhanced 18F‐FDG‐PET/CT followed by a neck dissection as a standard of reference were included. The contrast‐enhanced CT part, the 18F‐FDG‐PET part, the non‐enhanced 18F‐FDG‐PET/CT part, and the contrast‐enhanced 18F‐FDG‐PET/CT were assessed separately for correct N classification and the differentiation of N0 versus N+.

Results.

Contrast‐enhanced 18F‐FDG‐PET/CT, non‐enhanced 18F‐FDG‐PET/CT, and contrast‐enhanced CT are equally accurate for correct neck staging. Regarding pN0 versus pN+, contrast‐enhanced CT and contrast‐enhanced 18F‐FDG‐PET/CT are superior to non‐enhanced 18F‐FDG‐PET/CT (p = .017).

Conclusion.

Contrast‐enhanced CT and contrast‐enhanced 18F‐FDG‐PET/CT perform equally and better than non‐enhanced 18F‐FDG‐PET/CT in detecting CLNM in tonsillar SCC. Therefore, in patients scheduled for 18F‐FDG‐PET/CT, we strongly suggest performing a contrast‐enhanced 18F‐FDG‐PET/CT, which is not routine in most centers. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Insulin‐like growth factor II mRNA‐binding protein 3: A novel prognostic biomarker for oral squamous cell carcinoma
Authors: Li Shengjin , Cha JeongDan , Kim Jin , Kim Ki‐Yeol , Kim Hyung‐Jun , Nam Woong , Cha In‐Ho
Published: July 2010

Background.

Oral squamous cell carcinoma (OSCC) is caused by multiple factors, including carcinogen exposure. Insulin‐like growth factor II mRNA‐binding protein 3 (IMP3) is highly expressed in various cancer cells but is rarely expressed in normal cells. We investigated whether IMP3 can be used as a prognostic biomarker for OSCC.

Methods.

We performed immunohistochemistry and Western blotting to examine IMP3 expression in human tissues. We also investigated correlations among IMP3 expression, clinicopathologic factors, and overall survival.

Results.

IMP3 was overexpressed in OSCC cells. The expression was correlated with high histologic grade, lymph node metastasis, and advanced tumor and clinical stages. Univariate analysis indicated that advanced clinical stages, lymph node metastases, and IMP3 expression were predictive factors for OSCC. Multivariate analysis showed that IMP3 expression was an independent prognostic indicator for OSCC.

Conclusions.

IMP3 expression was related to various clinicopathologic factors. IMP3 expression was an independent prognostic factor in patients with OSCC. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Paratracheal lymph node dissection in cancer of the larynx, hypopharynx, and cervical esophagus: The need for guidelines
Authors: de Bree Remco , Leemans C. René , Silver Carl E. , Robbins K. Thomas , Rodrigo Juan P. , Rinaldo Alessandra , Takes Robert P. , Shaha Ashok R. , Medina Jesus E. , Suárez Carlos , Ferlito Alfio
Published: July 2010

In laryngeal, hypopharyngeal, and cervical esophageal carcinomas, the paratracheal lymph nodes (PTLN) may be at risk for lymph node metastasis. The presence of PTLN metastasis is an important prognostic factor for the development of mediastinal and distant metastases, stomal recurrence, and disease‐free and overall survival. Studies on PTLN metastasis are scarce. In most studies, PTLN dissection has not been routinely performed, and selection criteria for PTLN dissection are usually not well defined. Therefore, in most reported studies, selection bias is present and results are difficult to compare. The reported prevalence of PTLN metastases varies according to the site and stage of the primary tumor: subglottic cancer, transglottic cancer, and glottic cancer with subglottic extension have a higher risk of PTLN metastases. Diagnostic imaging is not sufficiently reliable to detect occult PTLN metastases and avoid unnecessary PTLN dissections. PTLN dissection is associated with limited morbidity, but damage to major vessels may occur, and because of exposure of these vessels PTLN may increase the morbidity of fistulae that can occur after total laryngectomy. The dissection may produce hypocalcemia, if performed bilaterally. Nevertheless, the limited morbidity and high rate of metastasis in specific laryngeal, hypopharyngeal, and cervical esophageal carcinomas argue in favor of routine elective PTLN treatment for these tumors. Large prospective studies are needed to identify the patients at risk with primary tumors in more detail. Moreover, improved diagnostic imaging is needed to detect (occult) PTLN metastases more reliably. Based on future studies, clinical guidelines have to be developed to avoid undertreatment and overtreatment. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Insulin‐like growth factor‐1 receptor inhibitor, AMG‐479, in cetuximab‐refractory head and neck squamous cell carcinoma
Authors: Chung Christine H. , Pohlmann Paula R. , Rothenberg Mace L. , Burkey Brian B. , Parker Joel , Palka Kevin , Aulino Joseph , Puzanov Igor , Murphy Barbara
Published: July 2010

Background

Recurrent head and neck squamous cell carcinoma (HNSCC) remains a difficult cancer to treat. Here, we describe a patient with HNSCC who had complete response to methotrexate (MTX) after progressing on multiple cytotoxic agents, cetuximab, and AMG‐479 (monoclonal antibody against insulin‐like growth factor‐1 receptor [IGF‐1R]).

Methods

The clinical information was collected by a retrospective medical record review under an Institutional Review Board–approved protocol. From 4 tumors and 2 normal mucosal epithelia, global gene expression, and IGF‐1R and dihydrofolate reductase (DHFR) protein levels were determined.

Results

Effective target inhibition in the tumor was confirmed by the decreased protein levels of total and phospho‐IGF‐1R after treatment with AMG‐479. Decreased level of DHFR and conversion of a gene expression profile associated with cetuximab‐resistance to cetuximab‐sensitivity were also observed.

Conclusion

This suggests that the combination of AMG‐479 and MTX or cetuximab may be a promising therapeutic approach in refractory HNSCC. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
An unusual cause of chest pain: Mycobacterium avium complex and the immune reconstitution inflammatory syndrome
Authors: Lin Richard J. , Song Jie
Published: July 2010

The HIV‐associated immune reconstitution inflammatory syndrome usually manifests as new infections or worsening of pre‐existing infections during the first few months of initiating anti‐retroviral therapy. It is commonly associated with local or systemic inflammation, presumably due to rapid reconstitution of host immune system. Here we describe a unique case of the immune reconstitution inflammatory syndrome presenting as acute pericarditis and pericardial effusion caused by mycobacterium avium complex. We also demonstrate that judicious use of steroids, along with pathogen specific antimicrobial therapy, can prevent local complications of the inflammatory response. Journal of Hospital Medicine 2010. © 2010 Society of Hospital Medicine.
Amino acids binding to Zn2+‐cyclen molecular receptor in aqueous solution
Authors: Vargová Z. , Balentová E. , Walko M. , Arabuli L. , Hermann P. , Lukeš I.
Published: July 2010

Potentiometric titrations and1H NMR spectroscopic studies of amino acids binding to the [ZnL]2+‐complex where L = cyclen in aqueous solution provide information concerning complexing species identity, their stability, and coordination mode declaration. The amino acids form stable ternary [ZnL(HLn)]2+and [ZnL(Ln)]+complexes. The observations indicate bidentate coordination mode of the deprotonated amino acids, involving both the amine and the carboxylate functions to the [ZnL]2+complex in pH region of about 7.5–9.5. The determined stability constants indicate that [ZnL]2+complex is a very efficient receptor for simple amino acids such as glycine and alanine. Copyright © 2010 John Wiley & Sons, Ltd.
In vivo sodium imaging of human patellar cartilage with a 3D cones sequence at 3 T and 7 T
Authors: Staroswiecki Ernesto , Bangerter Neal K. , Gurney Paul T. , Grafendorfer Thomas , Gold Garry E. , Hargreaves Brian A.
Published: July 2010

Purpose:

To compare signal‐to‐noise ratios (SNRs) and T*2 maps at 3 T and 7 T using 3D cones from in vivo sodium images of the human knee.

Materials and Methods:

Sodium concentration has been shown to correlate with glycosaminoglycan content of cartilage and is a possible biomarker of osteoarthritis. Using a 3D cones trajectory, 17 subjects were scanned at 3 T and 12 at 7 T using custom‐made sodium‐only and dual‐tuned sodium/proton surface coils, at a standard resolution (1.3 × 1.3 × 4.0 mm3) and a high resolution (1.0 × 1.0 × 2.0 mm3). We measured the SNR of the images and the T*2 of cartilage at both 3 T and 7 T.

Results:

The average normalized SNR values of standard‐resolution images were 27.1 and 11.3 at 7 T and 3 T. At high resolution, these average SNR values were 16.5 and 7.3. Image quality was sufficient to show spatial variations of sodium content. The average T*2 of cartilage was measured as 13.2 ± 1.5 msec at 7 T and 15.5 ± 1.3 msec at 3 T.

Conclusion:

We acquired sodium images of patellar cartilage at 3 T and 7 T in under 26 minutes using 3D cones with high resolution and acceptable SNR. The SNR improvement at 7 T over 3 T was within the expected range based on the increase in field strength. The measured T*2 values were also consistent with previously published values. J. Magn. Reson. Imaging 2010;32:446–451. © 2010 Wiley‐Liss, Inc.
Can MR fluoroscopic triggering technique and slow rate injection provide appropriate arterial phase images with reducing artifacts on gadoxetic acid‐DTPA (Gd‐EOB‐DTPA)‐enhanced hepatic MR imaging?
Authors: Haradome Hiroki , Grazioli Luigi , Tsunoo Mika , Tinti Rita , Frittoli Barbara , Gambarini Sebastiana , Morone Mario , Motosugi Utaroh , Colagrande Stefano
Published: July 2010

Purpose:

To evaluate whether using MR fluoroscopic triggering technique and slow rate injection improves the quality of arterial phase images in gadoxetic acid‐DTPA‐enhanced (Gd‐EOB‐DTPA) MR imaging because of proper acquisition timing and reduction of artifacts.

Materials and Methods:

Two hundred sixteen patients undergoing examination for liver diseases were retrospectively reviewed. All MR images were obtained with two Gd‐EOB‐DTPA injection protocols: (i) a combination protocol, in which the MR fluoroscopic triggering technique and slow rate injection (1 mL/s) were used; and for comparison, (ii) a conventional protocol, in which adjusted fixed scan delay and ordinary rate injection (2 mL/s) were adopted. Signal‐to‐noise ratio (SNR) of aorta, portal vein, and liver parenchyma on arterial phase images were calculated. Two blinded readers independently evaluated the obtained arterial phase images in terms of acquisition timing and degree of artifacts.

Results:

The SNRs of aorta and portal vein on arterial phase images were significantly higher in the combination protocol group (aorta/portal: 221.9 ± 91.9/197.1 ± 89.8) than that in the conventional protocol group (aorta/portal: 169.8 ± 97.4/92.7 ± 48.5) (P < 0.05). The acquisition timing for arterial phase images with the combination protocol was significantly better than that with the conventional protocol (P < 0.01). The image quality of the combination protocol was significantly higher than that of the conventional protocol (P < 0.01). The occurrence rate of moderate or severe degree of artifacts in the conventional protocol (38.0%) was more prominent than that in the combination protocol (18.5%).

Conclusion:

The combination of the MR fluoroscopic triggering technique and slow rate injection provides proper arterial phase images and reduces the artifacts in Gd‐EOB‐DTPA MR imaging. J. Magn. Reson. Imaging 2010;32:334–340. © 2010 Wiley‐Liss, Inc.
International reproducibility of single breathhold T2* MR for cardiac and liver iron assessment among five thalassemia centers
Authors: Kirk Paul , He Taigang , Anderson Lisa J. , Roughton Michael , Tanner Mark A. , Lam Wynnie W.M. , Au Wing Y. , Chu Winnie C.W. , Chan Godfrey , Galanello Renzo , Matta Gildo , Fogel Mark , Cohen Alan R. , Tan Ru San , Chen Kevin , Ng Ivy , Lai Angie , Fucharoen Suthat , Laothamata Jiraporn , Chuncharunee Suporn , Jongjirasiri Sutipong , Firmin David N. , Smith Gillian C. , Pennell Dudley J.
Published: July 2010

Purpose:

To examine the reproducibility of the single breathhold T2* technique from different scanners, after installation of standard methodology in five international centers.

Materials and Methods:

Up to 10 patients from each center were scanned twice locally for local interstudy reproducibility of heart and liver T2*, and then flown to a central MR facility to be rescanned on a reference scanner for intercenter reproducibility. Interobserver reproducibility for all scans was also assessed.

Results:

Of the 49 patients scanned, the intercenter reproducibility for T2* was 5.9% for the heart and 5.8% for the liver. Local interstudy reproducibility for T2* was 7.4% for the heart and 4.6% for the liver. Interobserver reproducibility for T2* was 5.4% for the heart and 4.4% for the liver.

Conclusion:

These data indicate that T2* MR may be developed into a widespread test for tissue siderosis providing that well‐defined and approved imaging and analysis techniques are used. J. Magn. Reson. Imaging 2010;32:315–319. © 2010 Wiley‐Liss, Inc.
Impact of motion on T1 mapping acquired with inversion recovery fast spin echo and rapid spoiled gradient recalled‐echo pulse sequences for delayed gadolinium‐enhanced MRI of cartilage (dGEMRIC) in volunteers
Authors: Studler Ueli , White Lawrence M. , Andreisek Gustav , Luu Sheena , Cheng Hai‐Ling Margaret , Sussman Marshall S.
Published: July 2010

Purpose:

To evaluate the impact of motion on T1 values acquired by using either inversion‐recovery fast spin echo (IR‐FSE) or three‐dimensional (3D) spoiled gradient recalled‐echo (SPGR) sequences for delayed gadolinium‐enhanced magnetic resonance imaging of cartilage (dGEMRIC) in volunteers.

Materials and Methods:

Single‐slice IR‐FSE and 3D SPGR sequences were applied to perform dGEMRIC in five healthy volunteers. A mutual information‐based approach was used to correct for image misregistration. Displacements were expressed as averaged Euclidean distances and angles. Averages of differences in goodness of fit (Δχ2) tests and averages of relative differences in T1 values (ΔT1) before and after motion correction were computed.

Results:

Maximum Euclidean distance was 3.5 mm and 1.2 mm for IR‐FSE and SPGR respectively. Mean ± SD of Δχ2 were 10.18 ± 8.4 for IR‐FSE and −1.37 ± 5.5 for SPGR. Mean ± SD of ΔT1 were 0.008 ± 0.0048 for IR‐FSE and −0.002 ± 0.019 for FSPGR. Pairwise comparison of Δχ2 values showed a significant difference for IR‐FSE, but not for 3D‐SPGR. Significantly greater variability in T1 values was also noted for IR‐FSE than for 3D‐SPGR.

Conclusion:

Involuntary motion has a significant influence on T1 values acquired with IR‐FSE, but not with 3D‐SPGR in healthy volunteers. J. Magn. Reson. Imaging 2010;32:394–398. © 2010 Wiley‐Liss, Inc.
Effect of hyoscine butylbromide (HBB) on the uterine corpus: Quantitative assessment with T2‐weighted (T2W) MRI in healthy volunteers
Authors: Fujimoto Koji , Nakai Asako , Okada Tomohisa , Ikeuchi Takashi , Satogami Naoe , Daido Sayaka , Yakami Masahiro , Togashi Kaori
Published: July 2010

Purpose:

To investigate effects of hyoscine butylbromide (HBB) on the appearance of three zonal anatomy of the uterine corpus on T2‐weighted images (T2WI).

Materials and Methods:

Sagittal T2WI of the pelvis were acquired before and after intramuscular administration of HBB with interval of 10 minutes in 22 healthy volunteers. By drawing polygonal regions of interest (ROIs), the uterine corpus was delineated into outer myometrium (OM), junctional zone (JZ), and endometrium (EM) in 20 subjects. Areas (mm2) and relative signal intensity (rSI) of each layer were compared between pre‐HBB and post‐HBB administration images by using paired t‐tests. Histogram analysis was conducted for the uterine layers and changes were visualized.

Results:

Areas of OM were significantly increased (P = 0.014) and mean rSI of JZ and OM were significantly increased (P = 0.007 and 0.001, respectively) after administration of HBB. Histogram showed an increase in the number of pixels with higher rSI in the OM, which was considered to be caused by an increase in interstitial fluid and vascular dilatation. EM did not show significant changes.

Conclusion:

Layer‐wise ROI analyses demonstrated changes in the area and rSI in T2WI of the uterus after HBB administration. Histogram analysis contributed to the investigation of signal changes. J. Magn. Reson. Imaging 2010;32:441–445. © 2010 Wiley‐Liss, Inc.
MRI of iron‐oxide labelled transplanted hepatocytes in mice: Effect of treatment with cyclophosphamide
Authors: Leconte Isabelle , Pallu Stéphane , Abarca‐Quinones Jorge , Michoux Nicolas , Peeters Frank , Radermacher Kim , Sempoux Christine , Najimi Mustapha , Sokal Etienne , Van Beers Bernard E.
Published: July 2010

Purpose:

To assess if 1.5T MRI can be used to study the transport to the liver, the intrahepatic distribution and engraftment of iron‐oxide labelled hepatocytes in cyclophosphamide‐treated and untreated mice.

Materials and Methods:

Hepatocytes were isolated from C57bl/6 mice and were labelled with 1.63 μm iron‐oxide particles. Seventeen mice were pretreated with cyclophosphamide to disrupt the sinusoidal endothelium and 15 were left untreated. Seven days after splenic injection of the labelled hepatocytes, T2*‐weighted gradient‐echo images at 1.5T were acquired. The hepatic transport, distribution and engraftment of the labelled hepatocytes were assessed with signal intensity (SI) and T2* measurements, electron paramagnetic resonance (EPR), texture analysis and histology.

Results:

Lower hepatic SI (P = 0.005), lower T2* (P = 0.033) and larger number of particles at histology (P = 0.006) suggested increased transport to the liver of labelled hepatocytes in cyclophosphamide‐treated mice versus untreated mice. At histology, most particles were located in Kupffer cells. Particles distribution was heterogeneous. No difference between both groups was observed at texture analysis.

Conclusion:

MRI is useful to assess the transport to the liver and intrahepatic distribution of transplanted labelled hepatocytes. The preferential location of iron‐oxide particles within Kupffer cells after seven days limits the value of MRI for assessing hepatocyte engraftment. J. Magn. Reson. Imaging 2010;32:367–375. © 2010 Wiley‐Liss, Inc.
Improved homogeneity of the transmit field by simultaneous transmission with phased array and volume coil
Authors: Avdievich Nikolai I. , Oh Sukhoon , Hetherington Hoby P. , Collins Christopher M.
Published: July 2010

Purpose:

To improve the homogeneity of transmit volume coils at high magnetic fields (≥4 T). Due to radiofrequency (RF) field/tissue interactions at high fields, 4 T to 8 T, the transmit profile from head‐sized volume coils shows a distinctive pattern with relatively strong RF magnetic field B1 in the center of the brain.

Materials and Methods:

In contrast to conventional volume coils at high field strengths, surface coil phased arrays can provide increased RF field strength peripherally. In theory, simultaneous transmission from these two devices could produce a more homogeneous transmission field. To minimize interactions between the phased array and the volume coil, counter rotating current (CRC) surface coils consisting of two parallel rings carrying opposite currents were used for the phased array.

Results:

Numerical simulations and experimental data demonstrate that substantial improvements in transmit field homogeneity can be obtained.

Conclusion:

We have demonstrated the feasibility of using simultaneous transmission with human head‐sized volume coils and CRC phased arrays to improve homogeneity of the transmit RF B1 field for high‐field MRI systems. J. Magn. Reson. Imaging 2010;32:476–481. © 2010 Wiley‐Liss, Inc.
Single breathhold cardiac CINE imaging with multi‐echo three‐dimensional hybrid radial SSFP acquisition
Authors: Liu Jing , Wieben Oliver , Jung Youngkyoo , Samsonov Alexey A. , Reeder Scott B. , Block Walter F.
Published: July 2010

Purpose:

To achieve single breathhold whole heart cardiac CINE imaging with improved spatial resolution and temporal resolution by using a multi‐echo three‐dimensional (3D) hybrid radial SSFP acquisition.

Materials and Methods:

Multi‐echo 3D hybrid radial SSFP acquisitions were used to acquire cardiac CINE imaging within a single breathhold. An optimized interleaving scheme was developed for view ordering throughout the cardiac cycle.

Results:

Whole heart short axis views were acquired with a spatial resolution of 1.3 × 1.3 × 8.0 mm3 and temporal resolution of 45 ms, within a single 17 s breathhold. The technique was validated on eight healthy volunteers by measuring the left ventricular volume throughout the cardiac cycle and comparing with the conventional 2D multiple breathhold technique. The left ventricle functional measurement bias of our proposed 3D technique from the conventional 2D technique: end diastolic volume −3.3 mL ± 13.7 mL, end systolic volume 1.4 mL ± 6.1 mL, and ejection fraction −1.7% ± 4.3%, with high correlations 0.94, 0.97, and 0.91, accordingly.

Conclusion:

A multi‐echo 3D hybrid radial SSFP acquisition was developed to allow for a whole heart cardiac CINE exam in a single breathhold. Cardiac function measurements in volunteers compared favorably with the standard multiple breathhold exams. J. Magn. Reson. Imaging 2010;32:434–440. © 2010 Wiley‐Liss, Inc.
Cathepsin B contributes to traumatic brain injury‐induced cell death through a mitochondria‐mediated apoptotic pathway
Authors: Luo Cheng‐Liang , Chen Xi‐Ping , Yang Rui , Sun Yu‐Xia , Li Qian‐Qian , Bao Hai‐Jun , Cao Qiang‐Qiang , Ni Hong , Qin Zheng‐Hong , Tao Lu‐Yang
Published: July 2010

It has been reported that lysosomal proteases play important roles in ischemic and excitotoxic neuronal cell death. We have previously reported that cathepsin B expression increased remarkably after traumatic brain injury (TBI). The present study sought to investigate the effects of a selective cathepsin B inhibitor (CBI) [N‐L‐3‐trans‐prolcarbamoyloxirane‐2‐carbonyl)‐L‐isoleucyl‐L‐proline] on cell death and behavioral deficits in our model. We examined the levels of cathepsin B enzymatic activity and its expression by double labelling damaged cells in the brain slice with propidium iodide (PI) and anticathepsin B. The results showed an elevated enzymatic activity associated with TBI‐induced increase in a mature form of cathepsin B, suggesting that cathepsin B may play a role in TBI‐induced cell injury. PI was found to label cells positive for the neuronal‐specific nuclear marker NeuN, whereas fewer GFAP‐positive cells were labelled by PI, suggesting that neurons are more sensitive to cell death induced by TBI. Additionally, we found that pretreatment with CBI remarkably attenuated TBI‐induced cell death, lesion volume, and motor and cognitive dysfunction. To analyze the mechanism of action of cathepsin B in the cell death signaling pathway, we assessed DNA fragmentation by electrophoresis, Bcl‐2/Bax protein expression levels, Bid cleavage, cytochrome c release, and caspase‐3 activation. The results imply that cathepsin B contributes to TBI‐induced cell death through the present programmed cell necrosis and mitochondria‐mediated apoptotic pathways. © 2010 Wiley‐Liss, Inc.
Ohne Laser produzieren geht nicht mehr
Authors: Treffert Claudia
Published: July 2010

Der Laser hat die Blechbearbeitung enorm beflügelt und sich zum unentbehrlichen Werkzeug entwickelt. Wie und warum, das lässt sich am Beispiel eines der ältesten deutschen Blechbearbeitungs‐Unternehmen sehr gut erkennen.
Commercial Exploration of High‐Temperature Superconductivity
Authors: Maher Eamonn , Delmdahl Ralph
Published: July 2010

Superconductivity, which is the condition in which the electrical resistance of a material drops to zero, was discovered nearly 100 years ago. Since that time, large superconducting magnets such as those used in magnetic resonance imaging (MRI), nuclear magnetic resonance (NMR) and big physics experiments have been developed and can now be regarded as being commercial products extending our capabilities in medicine and science. Yet many industrial applications of high temperature superconductivity (HTS) are on the horizon waiting to enter the marketplace. Currently, numerous manufacturers are working on improving and upscaling HTS materials, which operate at liquid nitrogen temperatures, and the most promising configuration for these materials is in the form of long tapes also known as coated conductors. These coated conductors are wound into coils in order to produce electrical components such as motors, magnets, transformers etc. Depending on the component to be made, there is an alternative to fabricating long unit lengths of superconducting tape, and in forming stable robust windings utilizing them. Now, a new technique has been developed which is using pulsed laser deposition (PLD) to deposit a series of layers of superconducting material directly on to the surface of a cylinder and patterning them into coils. This configuration provides a very direct route for the production of components that conventionally involve winding processes. This article explores how coated conductor cylinders can be produced utilizing this technique and explains why industriallyproven excimers represent the optimum choice of laser source for this emergingtechnology.
Maßgeschneiderte Oberflächen und Bauteile
Authors: Gasser Andres , Meiners Wilhelm , Weisheit Andreas , Willenborg Edgar , Stollenwerk Jochen , Wissenbach Konrad
Published: July 2010

Der Einsatz von Laserstrahlung eröffnet neue Möglichkeiten sowohl in der Verbesserung von Oberflächeneigenschaften als auch in der Fertigung und instandsetzung von Bauteilen. Durch eine lokale Wärmeeinbringung mit Laserstrahlung erfolgt eine gezielte Anpassung der Randschichteigenschaften an die Funktionsbeanspruchung bei gleichzeitig minimalem Verzug bzw. minimalem Wärmeeintrag in den Substratwerkstoff.
Microstructure and property development in spray formed and extruded Al‐Mg‐Li‐Zr alloys for aerospace and autosport applications
Authors: Hogg S. C. , Mi J. , Nilsen K. E. , Liotti E. , Grant P. S.
Published: July 2010

Low density Al‐4Mg‐1.3Li‐0.4Zr and Al‐6Mg‐1.6Li‐0.4Zr alloys were spray formed and the billets extruded under a range of conditions. The alloy compositions were selected to provide an attractive balance of tensile strength and elongation, without relying on complex post‐processing and heat treatments – and are therefore suitable for complex cross section extrusions and free from quench distortion. The as‐spray formed microstructures showed fine homogeneous, equiaxed grains with an average size of 10–15 μm. Firstly, a laboratory scale extrusion was carried out to extrude 30 mm diameter billets into 7.5 mm diameter cross‐section and to investigate the effects of temperature and ram speeds on microstructural development. The microstructure after extrusion at 400°C was partially dynamically recrystallised with a ∼︁0.5 area fraction of ∼︁1 μm grains and the remainder were unrecrystallised elongated grains. Electron backscatter diffraction showed a mixed <111> + <100> double fibre texture. After peak age hardening at 150°C for 96 h, the Al‐6Mg‐1.6Li‐0.4Zr alloy showed a 0.2% proof strength of 495 MPa, a tensile strength of 553 MPa and elongation to failure of 8.5%; Al‐4Mg‐1.3Li‐0.4Zr showed a 0.2% proof strength of 392 MPa, a tensile strength of 476 MPa and an elongation of 10%. Subsequently, large‐scale complex cross‐section were extruded at ∼︁400°C. Due to the complexity of the cross‐sections and the non‐axisymetric deformation, the fibre texture was distorted to FCC rolled Copper and Brass orientations. After a dual‐step age hardening treatment of 130°C for 8h followed by 160°C for 8h, the proof strength, ultimate strength and elongations were 340 MPa, 470 MPa and 16% respectively. The combination of relatively simple process steps, high strength and ductility/formability, and low distortion in complex sections demonstrated the strong potential for these low density alloys in aerospace and autosport applications.
Basic principles and application potentials of cold gas spraying
Authors: Klassen T. , Gärtner F. , Schmidt T. , Kliemann J.‐O. , Onizawa K. , Donner K.‐R. , Gutzmann H. , Binder K. , Kreye H.
Published: July 2010

Cold spraying is a well‐established coating technology for several materials and applications. The formation of dense microstructures occurs only by the plastic deformation of particles hitting the substrate with sufficiently high kinetic energies. Limited thermal influences well below the melting temperatures of respective spray materials and very short time scales make the process suitable for heat sensitive materials. For optimum spraying conditions and coating performance, a comprehensive understanding of the cold spray process and bonding mechanisms is required. This presentation summarizes the current model for coating formation based on adiabatic shear instabilities. Computer simulations visualize the bonding process and allow for extracting critical parameters that define the “window of deposition”. For selected materials, a correlation between powder characteristics, particle impact conditions and coating properties is shown. Furthermore, the state of the art in spraying equipment is reviewed. Special emphasis is put on recent improvements that ensure better coating performance and widen the range of sprayable materials. Finally, different application examples are presented to elucidate the potential for a variety of coating and substrate materials.

Das Kaltgasspritzen ist als Beschichtungstechnologie für mehrere Werkstoffe und Anwendungen bereits etabliert. Dichte Schichtmikrostrukturen entstehen, indem Pulverpartikel mit hoher kinetischer Energie auf ein zu beschichtendes Substrat aufprallen und sich dabei stark plastisch verformen. Da die Prozesstemperaturen deutlich unter dem Schmelzpunkt des jeweiligen Materials liegen und die Prozessdauern sehr kurz sind, eignet sich dieses Verfahren auch für temperatur‐ oder oxidationsempfindliche Werkstoffe. Für die Optimierung der Prozessparameter und Schichteigenschaften ist ein umfassendes Verständnis des Spritzprozesses und der Bindemechanismen notwendig. Diese Arbeit fasst zunächst das aktuelle Modell für die Schichtbildung zusammen, das auf adiabatischen Scherinstabilitäten basiert. Computersimulationen veranschaulichen den Bindeprozess und erlauben die Erfassung kritischer Parameter, die das sogenannte „Spritzfenster”︁ definieren. Für ausgewählte Materialien wird der Zusammenhang zwischen Pulverparametern, Aufprallbedingungen und Schichteigenschaften gezeigt. Darüber hinaus wird der aktuelle Stand der Spritztechnik mit den bisherigen Entwicklungsstufen verglichen, insbesondere in Hinblick auf neuere Entwicklungen, die zu besseren Schichteigenschaften führen und die Palette spritzbarer Werkstoffe erweitern. Abschließend werden verschiedene Anwendungsbeispiele präsentiert, um das Potenzial für eine Vielzahl von Schicht und Substratwerkstoffen zu demonstrieren.
Wear‐protective cermet coatings for forming tools
Authors: Tillmann W. , Vogli E. , Baumann I. , Krebs B. , Nebel J.
Published: July 2010

Two innovative thermal spray techniques have been investigated to manufacture wear protective coatings for forming tools. A Twin Arc Spray process (TWAS), with an AS‐850 cored wire containing fused tungsten carbides (FTC‐FeCCrMnSi), and a High Velocity Oxy‐Fuel (HVOF) spray technique, with fine WC12Co (18 μm) and Cr3C225(Ni20Cr) (28 μm) feedstock powders were employed. Coating characterizations regarding the hardness, roughness, porosity, deposition rate and deposition efficiency were conducted. In addition, the wear and friction behavior of all coatings were analyzed.

Zwei innovative thermische Spritzverfahren wurden untersucht, um Verschleißschutzschichten für Umformwerkzeuge herzustellen. Hierbei wurden ein Zweidraht‐Lichtbogenspritzprozess (TWAS) mit wolframschmelzkarbidhaltigen (WSC‐FeCrSi) AS 850 Fülldrähten und ein Hochgeschwindigkeitsflammspritzprozess mit feinen WC‐12Co (1‐8 μm) und Cr3C225(Ni20Cr) (28 μm) Ausgangspulvern verwendet. Schichtcharakterisierungen hinsichtlich Härte, Rauheit, Porosität, Auftragsrate und Auftragswirkungsgrad wurden durchgeführt. Zusätzlich wurden der Verschleiß und das Reibungsverhalten der Schichten analysiert.
Die Welt im Wandel
Authors: Rings Thomas , Lewe Tobias
Published: July 2010

Natürliche Ressourcen werden knapp, die Globalisierung schreitet voran und die Nachfrage nach Produkten wird vor allem in Asien steigen. Um auch in Zukunft erfolgreich zu sein, muss sich die chemische Industrie darauf einstellen.
Online‐NMR‐Spektroskopie – Mischungen messen im Fluss
Authors: Maiwald Michael , Steinhof Oliver , Hasse Hans
Published: July 2010

Reaktionen im Labor oder Prozesse im Technikum mit Kernresonanzspektroskopie zu verfolgen, ist bislang eher selten. Und das, obwohl die Methode im Durchfluss quantitativ analysiert und dabei technische Bedingungen wie Druck oder Temperatur nicht verändert.
C‐H‐Aktivierung: Neue Wege in der Synthese
Authors: Gräning Timm
Published: July 2010

Unpolare C‐H‐Bindungen in funktionelle Gruppen umzuwandeln – das war bisher mit konventionellen Methoden nur in mehreren Stufen zu erreichen. Die C‐H‐Aktivierung verspricht einen direkten Zugang zu chemischen Grundstoffen aus unreaktiven Alkanen. Sie bietet aber auch strategische Vorteile in der Synthese komplexer organischer Verbindungen.
Allein Herr im Haus
Authors: Guggolz Ernst
Published: July 2010

Chemieparks sind ein deutsches Produkt, ursprünglich entstanden als Reaktion auf zerfallende Chemiestandorte. Aber Park ist nicht gleich Park.
Wein auf Rezept?
Authors: Wamhoff Heinrich
Published: July 2010

Weininhaltsstoffe wie Polyphenole fördern die Gesundheit. Studien dazu versprechen ein langes Leben ohne Karzinome oder Demenz. Immer neue Untersuchungen bringen immer mehr Informationen über Wirkstoffe, nützliche Dosierungen und mögliche Nebenwirkungen.
25 Jahre BUA
Authors: Greim Heidrun
Published: July 2010

Eine Veranstaltung am 20. April in Frankfurt am Main blickte auf die Arbeit des Beratergremiums für Altstoffe zurück, die erfolgreiche Kooperation zwischen Wissenschaft, Industrie und Behörde.