bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of the Second Coordination Shell on the XANES Spectra of the Zn2+ Ion in Water and Methanol
Authors: Migliorati Valentina , Zitolo Andrea , Chillemi Giovanni , D'Angelo Paola
Published: January 2012

A quantitative analysis of the X‐ray absorption near‐edge structure (XANES) spectra of the Zn2+ ion in methanol and aqueous solution has been carried out starting from the microscopic description of the systems derived from molecular dynamics (MD) simulations. The different sensitivity of XANES towards the second‐shell solvent molecules in the two solvents has been highlighted: in methanol solution, the Zn2+ second solvation shell was found to provide a negligible contribution to the XANES spectrum, and it has been possible to reproduce the experimental data using a single coordination sphere in the calculation. Conversely, a reliable reproduction of the experimental spectrum of Zn2+ in aqueous solution could be obtained only by including the second‐shell water molecules in the calculation. The combination of MD and XANES was found to be essential to evaluate the contribution of the ion second solvation shell to the XANES spectra of a metal ion in organic solvents.
IVIg‐mediated amelioration of ITP in mice is dependent on sialic acid and SIGNR1
Authors: Schwab Inessa , Biburger Markus , Krönke Gerhard , Schett Georg , Nimmerjahn Falk
Published: January 2012

Intravenous immunoglobulin G (IVIg) therapy is widely used to treat autoimmune and inflammatory diseases. Recent evidence suggests that in mice, splenic resident cells might be important for the anti‐inflammatory activity of IVIg in a model of serum transfer arthritis. Splenectomized human immunothrombocytopenia (ITP) patients, however, still respond to IVIg therapy. To investigate whether the requirement of the spleen is essential for mouse ITP, we used a passive model of induced ITP and demonstrated that IVIg activity was functional in splenectomized animals. Further analysis showed that the IVIg‐mediated amelioration of platelet phagocytosis was fully dependent on terminal sialic acid residues in the IVIg preparation and could be blocked with a specific ICAM3 grabbing nonintegrin‐related 1 (SIGNR1) specific antibody. These results suggest that, similar to the human system, a spleen‐independent but sialic acid‐ and SIGNR1‐dependent pathway is responsible for IVIg‐mediated suppression of autoantibody‐dependent platelet depletion in mice.
Crystal‐Phase‐ and Morphology‐Controlled Synthesis of Fe2O3 Nanomaterials
Authors: Mou Xiaoling , Li Yong , Zhang Bingsen , Yao Lide , Wei Xuejiao , Su Dang Sheng , Shen Wenjie
Published: January 2012

α‐ and γ‐Fe2O3 nanorods have been prepared from a β‐FeOOH precursor that was obtained by aqueous‐phase precipitation of ferric chloride. The oxyhydroxide precursor had a rodlike shape with a diameter of 30–40 nm and a length of 400–500 nm. Calcination at 500 °C of the rod‐shaped oxyhydroxide in air yielded α‐Fe2O3 nanorods, whereas heating to reflux in polyethylene glycol (PEG) at 200 °C resulted in the formation of γ‐Fe2O3 nanorods. Both oxides inherited the rodlike morphology of the precursor but exposed different crystalline facets. When being used to catalyze NO reduction by CO, an environmentally important reaction in NO abatement, the γ‐Fe2O3 nanorods were much more active than the α‐Fe2O3 nanorods and showed an apparent crystal‐phase effect. This was because the γ‐Fe2O3 nanorods simultaneously exposed iron and oxygen ions on their surfaces, which facilitated the adsorption and activation of NO and CO molecules.
Sulfur–Nitrogen and Carbon–Nitrogen Bond Formation by Intermolecular Imination and Amidation without Catalyst
Authors: Ma Wen Bo , Li Sheng Nan , Zhou Zhong Hua , Shen Heng Shui , Li Xue , Sun Qiu , He Ling , Xue Ying
Published: January 2012

Imination and amidation of sulfides, sulfoxides, and olefins using 4H‐1,2,4‐triazole‐4‐amine as a nitrogen source with PhI(OAc)2 as an oxidant were achieved in moderate to high yields without the addition of a catalyst. The carbon–nitrogen and sulfur–nitrogen bond forming reactivity is consistent with a nitrene insertion mechanism in which the reactivity generally increases with decreasing N–H bond dissociation energy of the nitrogen source and increasing oxidation potential of the oxidant.
Controlling the Macroscopic Chirality of Organic Materials Based on 1,3,5‐Trialkynylbenzenes
Authors: Hennrich Gunther , Nieto‐Ortega Belén , Gómez‐Lor Berta , Gutierrez Entique , de Vega Laura , Cavero Emma , Ramírez Francisco J. , López Navarrete Juan T. , Casado Juan
Published: January 2012

By changing the position of the homochiral alkoxy substituents of C3‐symmetric 1,3,5‐trialkynylbenzenes from the center to the periphery, the macroscopic chirality of the resulting aggregates (crystals or fibers), studied by various spectroscopic and microscopic techniques, was inverted, as confirmed by single‐crystal X‐ray diffraction analysis.
Stereoselective Olefination and Regiospecific Vicinal Difunctionalization of Imines with α‐(Benzothiazol‐2‐ylsulfonyl) Carbonyl Compounds
Authors: Shao You‐Dong , Wu Xue‐Song , Tian Shi‐Kai
Published: January 2012

Depending on their structures, imines are able to undergo either olefination or vicinal difunctionalization with various α‐(benzothiazol‐2‐ylsulfonyl) carbonyl compounds in the absence of external bases. The olefination reaction of aromatic imines with α‐(benzothiazol‐2‐ylsulfonyl) carbonyl compounds proceeds smoothly in tetrahydrofuran at 70 °C to give structurally diverse α,β‐unsaturated esters, amides, and ketones in good to excellent yields and with extremely high (E) selectivity. In contrast, the carbon–nitrogen double bonds of cyclic imines and the carbon–carbon double bonds of α,β‐unsaturated imines are subjected to regiospecific vicinal difunctionalization with α‐(benzothiazol‐2‐ylsulfonyl) carbonyl compounds under the same reaction conditions to give a variety of benzothiazole derivatives in good to excellent yields. It is noteworthy that the benzothiazole moiety is present in a number of antitumor agents and bioluminescent molecules. In addition, plausible reaction pathways have been proposed to account for these transformations, and these are substantially supported by ESI‐MS analysis of the reaction mixtures.
Stereocontrolled Synthesis of the cis‐Hydroxydecalin System: Towards Biologically Active 19‐nor‐Clerodanes
Authors: Mirzayans Paul Malek , Pouwer Rebecca H. , Williams Craig M. , Bernhardt Paul V.
Published: January 2012

The 19‐nor‐clerodanes are compact, densely functionalized diterpenes based on a stereocentre‐rich decalin scaffold. To date only a few examples of the 19‐nor‐clerodanes have been synthesized, hence new flexible strategies are required. We herein describe the stereocontrolled construction of the cis‐hydroxy decalin core in a concise fashion.
Modified Screen‐Printed Electrodes Based on Oxidized Graphene Nanoribbons for the Selective Electrochemical Detection of Several Molecules
Authors: Valentini F. , Romanazzo D. , Carbone M. , Palleschi G.
Published: January 2012

An electrochemical study of several molecules has been carried out, using novel graphene‐modified screen printed electrodes (GN‐SPEs). Different analytical parameters have been optimized, as: the graphene concentration for a homogeneous coating of the electrode surfaces, the scan rates and the potential window for the electrochemical detection of potassium ferricyanide, catechol, hexaammineruthenium(III) chloride, sodium hexachloroiridate‐(III) hydrate, dopamine, epinephrine, L‐tyrosine, 3,4‐dihydroxyphenylacetic acid (DOPAC), ascorbic acid, uric acid, 4‐acetamidophenol (acetaminophen), NADH, H2O2, caffeic acid, guanine, and serotonin (5‐HT) hydrochloride. In addition, different experimental conditions were tested, especially the solvents used to obtain a stable graphene nanoribbon dispersion. Among these various analytes, especially good results were obtained with NADH which was detected at an applied potential of +0.44 V, vs.Ag/AgCl, compared to the +0.55 V at pristine SWCNT paste electrodes, [7]), and with a detection limit (of 200 µM), good sensitivity (1.70 µA/mM mm2), and good reproducibility (RSD% ranging from 3 to 20 for different SPEs used for each single point of calibration plot). Also dopamine, has been successfully detected at GN‐ SPEs even in the presence of an electrochemical interfering compound. Results for dopamine showed a good detection limit (of 4 µM), sensitivity (17.70 µA/mM mm2) and reproducibility (RSD% ranging from 7 to 20 for different SPEs used for each single point of calibration plot).
Goal‐oriented space–time adaptivity in the finite element Galerkin method for the computation of nonstationary incompressible flow
Authors: Besier Michael , Rannacher Rolf
Published: January 2012

This paper presents a general strategy for designing adaptive space–time finite element discretizations of the nonstationary Navier–Stokes equations. The underlying framework is that of the dual weighted residual method for goal‐oriented a posteriori error estimation and automatic mesh adaptation. In this approach, the error in the approximation of certain quantities of physical interest, such as the drag coefficient, is estimated in terms of local residuals of the computed solution multiplied by sensitivity factors, which are obtained by numerically solving an associated dual problem. In the resulting local error indicators, the effects of spatial and temporal discretization are separated, which allows for the simultaneous adjustment of time step and spatial mesh size. The efficiency of the proposed method for the construction of economical meshes and the quantitative assessment of the error is illustrated by several test examples. Copyright © 2012 John Wiley & Sons, Ltd.
Rab4 and Rab5 GTPase are required for directional mobility of endocytic vesicles in astrocytes
Authors: Potokar Maja , Lacovich Valentina , Chowdhury Helena H. , Kreft Marko , Zorec Robert
Published: January 2012

Rab4 and Rab5 GTPases are key players in the regulation of endocytosis. Although their role has been studied intensively in the past, it is still unclear how they regulate vesicle mobility. In particular, in astrocytes, the most abundant glial cells in the brain, vesicles have been shown to exhibit nondirectional and directional mobility, which can be intermittent, but the underlying switching mechanisms are not known. By using quantitative imaging, we studied the dynamics of single vesicle movements in astrocytes in real time, by transfecting them with different GDP‐ and GTP‐locked mutants of Rab4 and Rab5. Along with the localization of Rab4 and Rab5 on early and late endocytic compartments, we measured the apparent vesicle size by monitoring the area of fluorescent puncta and determined the patterns of vesicle mobility in the presence of wild‐type and Rab mutants. Dominant‐negative and dominant‐positive mutants, Rab4 S22N, Rab5 S34N and Rab4 Q67L, Rab5 Q79L, induced an increase in the apparent vesicle size, especially Rab5 mutants. These mutants also significantly reduced vesicle mobility in terms of vesicle track length, maximal displacement, and speed. In addition, significant reductions in the fraction of vesicles exhibiting directional mobility were observed in cells expressing Rab4 S22N, Rab4 Q67L, Rab5 S34N, and Rab5 Q79L. Our data indicate that changes in the GDP‐GTP switch apparently not only affect fusion events in endocytosis and recycling, as already proposed, but also affect the molecular interactions determining directional vesicle mobility, likely involving motor proteins and the cytoskeleton. © 2012 Wiley Periodicals, Inc.
The moderating effects of organizational context on the relationship between voluntary turnover and organizational performance: Evidence from Korea
Authors: Kwon Kiwook , Chung Kweontaek , Roh Hyuntak , Chadwick Clint , Lawler John J.
Published: January 2012

Scholars have suggested that the relationship between voluntary turnover and organizational performance can be moderated by the organizational context in which turnover occurs. However, there are few empirical studies that examine such moderating effects. Using a sample of 161 firms in South Korea, this study investigates how the relationship between voluntary turnover and organizational performance is moderated by three context variables: (1) the degree of organizational usage of employee involvement practices, (2) the degree of organizational investment in employee training and development, and (3) the availability of potential workers. The results demonstrate that employee involvement practices significantly amplify the negative relationship between voluntary turnover and organizational performance, give marginal support for moderation from the availability of potential workers, and provide no support for moderation from the degree of organizational investment in employee training and development. We discuss theoretical and practical implications of this study for enriching our understanding of the relationship between voluntary turnover and organizational performance. © 2012 Wiley Periodicals, Inc.
Theory‐driven development of a comprehensive turnover‐attachment motive survey
Authors: Maertz Carl P. , Boyar Scott L.
Published: January 2012

Recent studies propose a theoretical framework of “eight forces” that purportedly captures all the distinct motives causing voluntary turnover decisions. Based on this framework, we develop the Turnover‐Attachment Motive Survey (TAMS) consisting of 18 scales, the most comprehensive model‐based turnover antecedent survey to date, facilitating more fully specified research models and more systematic diagnoses of turnover causes. Moreover, findings support behavioral inertia against quitting, psychological dissonance costs of quitting, supervisor continuance attachment, and coworker continuance attachment as significant predictors of turnover behavior for the first time in the literature. Overall, findings do suggest that our 18‐scale survey demonstrated adequate psychometric properties to justify its further use and development. We finally discuss the many uses of the TAMS for both turnover researchers and practitioners. © 2012 Wiley Periodicals, Inc.
Small is beautiful: Implications of reliability and statistical power for testing the efficacy of HR interventions
Authors: Horwitz Sujin K. , Horwitz Irwin B.
Published: January 2012

The development of optimal human resource practices is often contingent on the accurate statistical testing of potential interventions. Testing the efficacy of HR interventions can be enhanced by taking additional measures to improve statistical power, but the traditional means of increasing power through sample size are often beyond the cost and ability of HR professionals to pursue. This article, therefore, focuses on measurement procedures as an alternative way to increase statistical power for detecting HR intervention effects. Selection of reliable and appropriate measures and subsequent instrumentation are examined as efficacious and cost‐beneficial techniques that can be employed during the planning and designing stage of a study for augmenting statistical power to optimize business decision making. © 2012 Wiley Periodicals, Inc.
Shocks and final straws: Using exit‐interview data to examine the unfolding model's decision paths
Authors: Kulik Carol T. , Treuren Gerry , Bordia Prashant
Published: January 2012

The unfolding model emphasizes the role of shocks (jarring events that initiate exit cognitions) in the turnover process. In contrast to earlier survey‐based research, we used exit interviews to classify organizational leavers along the model's paths. The data provide support for the model but highlight several aspects of shocks not addressed by previous research. Employees on the same path may experience distinctly different shock subgroups (e.g., work or nonwork), some employees require shock combinations (e.g., push and pull shocks) to motivate leaving, and some dissatisfied employees experience shock‐like events (final straws) that confirm previous exit cognitions rather than initiate them. The research demonstrates how organizations can use exit interviews to better understand their employee exit patterns. © 2012 Wiley Periodicals, Inc.
Increasing HR's strategic participation: The effect of HR service quality and contribution expectations
Authors: Uen Jin Feng , Ahlstrom David , Chen Shu‐Yuan , Tseng Pai‐Wei
Published: January 2012

Strategic participation is important for HR professionals who wish to have increased influence in their organizations. While a number of previous studies have suggested a link between strategic human resource management and firm performance, few have explored the specific factors enabling HR strategic participation. This study examines the impact of HR service quality and expectations of HR contributions on HR strategic participation. A total of 244 survey responses were received from 42 companies in Taiwan. All hypotheses were supported, thus signifying significant relationships between HR service quality, expectations of HR contributions, and HR strategic participation. The study results also indicate that HR professionals are able to proactively increase the value of HR in organizations by enhancing HR service quality and addressing potential internal customers' needs accordingly. © 2012 Wiley Periodicals, Inc.
Why does firm reputation in human resource policies influence college students? The mechanisms underlying job pursuit intentions
Authors: Wayne Julie Holliday , Casper Wendy J.
Published: January 2012

Business periodicals, such as Fortune magazine, rank organizations in lists such as the “Best Companies to Work For,” providing applicants with information about firms' human resource practices, including pay, benefits, work‐life, and diversity practices. It is not clear what influence this reputational information about HR practices has on applicant interest in pursuing employment or, more important, why it does so. Given that firms invest substantial resources in HR practices to vie for positions on these lists, the current study sought to fill these gaps in the literature. In the 2 (compensation) × 2 (work‐family) × 2 (diversity) factorial design, 232 college students read about magazine rankings in which a firm's reputation in each HR practice was manipulated as ranking either high or low relative to competitors. We examined perceptions of organizational prestige, anticipated organizational support, and anticipated role performance as mechanisms that explain the influence of HR practice reputation on job pursuit intentions. Our results indicate that a firm's reputation in compensation, work‐family, and diversity efforts increase college students' intentions to pursue employment with a firm. They do so because college students perceive that the organization is prestigious, will be supportive, and will foster their job performance. Our results suggest that a strong employer brand derived from employee‐centered HR practices is important for recruiting college students. © 2012 Wiley Periodicals, Inc.
EFFECTS OF IRRIGATION ON SOIL PHYSICO‐CHEMISTRY: A CASE STUDY OF THE TRIFFA PLAIN (MOROCCO)
Authors: Bendra Brahim , Fetouani Sanaa , Laffray Xavier , Vanclooster Marnik , Sbaa Mohamed , Aleya Lotfi
Published: January 2012

The Triffa Plain is the most productive irrigated agricultural zone in north‐eastern Morocco. Irrigated agriculture in (semi‐)arid regions may exert different pressures on soil resources, but in northern Africa these are often poorly documented. A field survey conducted in 2005 to assess soil quality in the region focuses on the soil's physico‐chemical parameters and analyses their spatial dependency on a regional scale. As most of the soils are light‐textured, with poor organic matter content and slightly basic pH, they are vulnerable to soil nutrient depletion. Multivariate analysis shows that organic matter content is well correlated to the soil's P and K content, while the total and active lime correlate well with the alkalinity and pH, which in turn correlate negatively with nitrate content and soil electrical conductivity. The spatial structure of the soil parameters can be modelled using Gaussian semi‐variograms, suggesting consistent spatial structuring of the parameters. The low nutritional status of the soils is compensated by important fertiliser supplements, leading to nutrient imbalances and further environmental deterioration. Copyright © 2012 John Wiley & Sons, Ltd.
Block copolymer arrangement and composition effects on protein conformation using atomic force microscope‐based antigen–antibody adhesion
Authors: Palacio M. L. B. , Schricker S. R. , Bhushan B.
Published: January 2012

The conformational changes of fibronectin (FN) deposited on various block copolymers where one block is composed of poly(methyl methacrylate) (PMMA) and the other block is either poly(acrylic acid) (PAA) or poly(2‐hydroxyethyl methacrylate) (PHEMA) were investigated using a functionalized atomic force microscope (AFM) tip. The tip was modified with an antibody sensitive to the exposure of the arginine–glycine–aspartic acid (RGD) groups in FN. By studying the adhesive interactions between the antibody and the proteins adsorbed on the block copolymer surface and phase imaging, it was found that the triblock copolymers PAA‐b‐PMMA‐b‐PAA and PMMA‐b‐PHEMA‐b‐PMMA, which both have large domain sizes, are conducive to the exposure of the FN RGD groups on the surface. On the basis of these results, it is concluded that the surface chemistry as well as the nanomorphology dictated by the block copolymer arrangement could both tune protein conformation and orientation and optimize cell adhesion to the biomaterial surface. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Collaboration in Multicultural Therapy: Establishing a Strong Therapeutic Alliance Across Cultural Lines
Authors: Asnaani Anu , Hofmann Stefan G.
Published: January 2012

Achieving effectiveness of psychotherapy across a diversity of patients continues to be a foremost concern, and the therapy alliance remains a critical component of such favorable outcome across theoretical orientations and treatment formats. This article offers concrete guidance grounded in empirical research on therapist behaviors and treatment features to enhance collaboration in multicultural therapy. This is followed by a multicultural case study of a patient presenting with several co‐morbid disorders to exemplify the application of these guidelines over the course of therapy.
Collaboration in Family Therapy
Authors: Tuerk Elena Hontoria , McCart Michael R. , Henggeler Scott W.
Published: January 2012

This article summarizes and illustrates the collaboration strategies used by several family therapies. The strategies used within multisystemic therapy (MST) are emphasized because it has demonstrated high rates of treatment completion and favorable outcomes in multiple clinical trials. Many of the collaboration strategies in family work are common to other forms of evidence‐based psychotherapy (e.g., reflective listening, empathy, reframing, and displays of authenticity and flexibility); however, some strategies are unique to family systems treatments, such as the identification of strengths across multiple systems in the youth's social ecology and the maintenance of a family (versus a child) focus during treatment. A case example illustrates collaboration and engagement in the context of MST.
Downstream of downstream processing: development of recycling strategies for biopharmaceutical processes
Authors: Grote Florian , Ditz Reinhard , Strube Jochen
Published: January 2012

BACKGROUND: Downstream processing plays a crucial role in biotechnological production processes. Product concentration and purification require complex, multi‐step operations, using significant amounts of chemical and auxiliary material. Today, design and optimization is important because the process development of biotechnological products is becoming more and more expensive. It is of great importance to improve sustainable development of eco‐efficient products and processes. Integrated process and product development leads to more efficient use of raw materials.

RESULTS: A new stepwise approach is proposed to develop recycling strategies for biopharmaceutical products, which can be implemented within an existing and approved process environment. This article describes the approach in detail and exemplifies the methodical procedure for characteristic reference processes. The theoretical recycling and separation tasks as well as possible strategies are defined and evaluated experimentally. An experimental model parameter determination in small scale is shown. In addition, concrete solutions are discussed due to solving regulatory constraints addressing comparability studies.

CONCLUSION: It is shown that development with the aim of intensification and full integration of the individual steps of bioprocess production (modules, unit operations) leads to an improvement in every single step at the same time. It follows clearly that consistent implementation represents a meaningful contribution to next generation bioproduction design. Copyright © 2012 Society of Chemical Industry
Improved B1 homogeneity of 3 tesla breast MRI using dual‐source parallel radiofrequency excitation
Authors: Rahbar Habib , Partridge Savannah C. , DeMartini Wendy B. , Gutierrez Robert L. , Parsian Sana , Lehman Constance D.
Published: January 2012

Purpose:

To compare breast MRI B1 homogeneity at 3 Tesla (T) with and without dual‐source parallel radiofrequency (RF) excitation.

Materials and Methods:

After institutional review board approval, we evaluated 14 consecutive breast MR examinations performed at 3T that included three‐dimensional B1 maps created separately with conventional single‐source and dual‐source parallel RF excitation techniques. We measured B1 values (expressed as % of intended B1) on each B1 map at nipple level in multiple bilateral locations: anterior, lateral, central, medial, and posterior. Mean whole breast and location specific B1 values were calculated and compared between right and left breasts using paired t‐test.

Results:

Mean whole breast B1 values differed significantly between right and left breasts with standard single‐source RF excitation (difference L‐R, Δ = 9.2%; P < 0.001) but not with dual‐source parallel RF excitation (Δ = 2.3%; P = 0.085). Location specific B1 values differed significantly between right and left on single‐source in the lateral (P = 0.014), central (P = 0.0001), medial (P = 0.0013), and posterior (P < 0.0001) locations. Conversely, mean B1 values differed significantly on dual‐source parallel RF excitation for only the anterior (P = 0.030) and lateral (P = 0.0003) locations.

Conclusion:

B1 homogeneity is improved with dual‐source parallel RF excitation on 3T breast MRI when compared with standard single‐source RF excitation technique. J. Magn. Reson. Imaging 2012;35:1222‐1226. © 2012 Wiley Periodicals, Inc.
Four‐dimensional phase contrast MRI with accelerated dual velocity encoding
Authors: Nett Elizabeth J. , Johnson Kevin M. , Frydrychowicz Alex , Del Rio Alejandro Munoz , Schrauben Eric , Francois Christopher J. , Wieben Oliver
Published: January 2012

Purpose:

To validate a novel approach for accelerated four‐dimensional phase contrast MR imaging (4D PC‐MRI) with an extended range of velocity sensitivity.

Materials and Methods:

4D PC‐MRI data were acquired with a radially undersampled trajectory (PC‐VIPR). A dual Venc (dVenc) processing algorithm was implemented to investigate the potential for scan time savings while providing an improved velocity‐to‐noise ratio. Flow and velocity measurements were compared with a flow pump, conventional 2D PC MR, and single Venc 4D PC‐MRI in the chest of 10 volunteers.

Results:

Phantom measurements showed excellent agreement between accelerated dVenc 4D PC‐MRI and the pump flow rate (R2 ≥ 0.97) with a three‐fold increase in measured velocity‐to‐noise ratio (VNR) and a 5% increase in scan time. In volunteers, reasonable agreement was found when combining 100% of data acquired with Venc = 80 cm/s and 25% of the high Venc data, providing the VNR of a 80 cm/s acquisition with a wider velocity range of 160 cm/s at the expense of a 25% longer scan.

Conclusion:

Accelerated dual Venc 4D PC‐MRI was demonstrated in vitro and in vivo. This acquisition scheme is well suited for vascular territories with wide ranges of flow velocities such as congenital heart disease, the hepatic vasculature, and others. J. Magn. Reson. Imaging 2012;35:1462–1471. © 2012 Wiley Periodicals, Inc.
Quantification of holmium‐166 loaded microspheres: Estimating high local concentrations using a conventional multiple gradient echo sequence with S0‐fitting
Authors: van de Maat Gerrit H. , Seevinck Peter R. , Bos Clemens , Bakker Chris J.G.
Published: January 2012

Purpose:

To provide a best estimate of the R value and hence of the local concentration of highly paramagnetic holmium‐166 loaded microspheres (HoMS) in voxels for which R cannot be characterized by conventional fitting of multigradient echo (MGE) data because of fast signal decay due to high local concentrations.

Materials and Methods:

A postprocessing method, S0‐fitting, was implemented in a conventional R fitting method that is used for quantification of HoMS. S0‐fitting incorporates the estimated initial amplitude of the free induction decay (FID) curve, S0, of neighboring voxels into the fitting procedure for voxels for which the conventional algorithm failed. The method was applied to HoMS in vitro and ex vivo in a rabbit liver. The performance of the S0‐fitting method was evaluated by comparing results qualitatively and quantitatively with results obtained with quantitative ultrashort TE imaging (qUTE).

Results:

Applying S0‐fitting provided a best estimate for R up to a value of about 2300 s−1 compared with a maximum value of about 1000 s−1 that could be characterized using conventional fitting. A good agreement was observed both qualitatively and quantitatively for in vitro experiments as well as for ex vivo rabbit liver experiments between results obtained with S0‐fitting and results obtained with qUTE imaging.

Conclusion:

S0‐fitting is a postprocessing method that can provide a best estimate of high R values that cannot be characterized by conventional relaxometry. The method can be applied to conventional MGE datasets and was shown to be beneficial for quantification of high local concentrations of holmium‐loaded microspheres. J. Magn. Reson. Imaging 2012;35:1453–1461. © 2012 Wiley Periodicals, Inc.
Comparison between intensity normalization techniques for dynamic susceptibility contrast (DSC)‐MRI estimates of cerebral blood volume (CBV) in human gliomas
Authors: Ellingson Benjamin M. , Zaw Taryar , Cloughesy Timothy F. , Naeini Kourosh M. , Lalezari Shadi , Mong Sandy , Lai Albert , Nghiemphu Phioanh L. , Pope Whitney B.
Published: January 2012

Purpose:

To compare “standardization,” “Gaussian normalization,” and “Z‐score normalization” intensity transformation techniques in dynamic susceptibility contrast magnetic resonance imaging (DSC‐MRI) estimates of cerebral blood volume (CBV) in human gliomas. DSC‐MRI is a well‐established biomarker for CBV in brain tumors; however, DSC‐MRI estimates of CBV are semiquantitative. The use of image intensity transformation algorithms provides a mechanism for obtaining quantitatively similar CBV maps with the same intensity scaling.

Materials and Methods:

The coefficient of variance (CV) in normal‐appearing white matter and relative contrast between tumor regions and normal tissue was compared between the three CBV transformations across five different MR scanners in 96 patients with gliomas.

Results:

The results suggest all normalization techniques improved variability and relative tumor contrast of CBV measurements compared with nonnormalized CBV maps. The results suggest Gaussian normalization of CBV maps provided slightly lower CV in normal white matter and provided slightly higher tumor contrast for glioblastomas (WHO grade IV) compared with other techniques.

Conclusion:

The results suggest Gaussian normalization of leakage‐corrected CBV maps may be the best choice for image intensity correction for use in large‐scale, multicenter clinical trials where MR scanners and protocols vary widely due to ease of implementation, lowest variability, and highest tumor to normal tissue contrast. J. Magn. Reson. Imaging 2012;35:1472–1477. © 2012 Wiley Periodicals, Inc.
Exploring the frontiers of synthetic eumelanin polymers by high‐resolution matrix‐assisted laser/desorption ionization mass spectrometry
Authors: Reale Samantha , Crucianelli Marcello , Pezzella Alessandro , d'Ischia Marco , De Angelis Francesco
Published: January 2012

New trends in material science and nanotechnologies have spurred growing interest in eumelanins black insoluble biopolymers derived by tyrosinase‐catalysed oxidation of tyrosine via 5,6‐dihydroxyindole (DHI) and its 2‐carboxylic acid (DHICA). Efficient antioxidant and photoprotective actions, associated with peculiar optoelectronic properties, are recognised as prominent functions of eumelanin macromolecules within the human and mammalian pigmentary system, making them unique candidates for the realisation of innovative bio‐inspired functional soft materials, with structure‐based physical–chemical properties. An unprecedented breakthrough into the mechanism of synthetic eumelanin buildup has derived from a detailed investigation of the oxidative polymerization of DHI and its N‐methyl derivative (NMDHI) by linear and reflectron matrix‐assisted laser/desorption ionization mass spectrometry. Regular collections of oligomers of increasing masses, spanning the entire m/z ranges up to 5000 Da (>30‐mer) and 8000 Da (> 50‐mer) for the two building blocks, respectively, were disclosed. It is the first time that the in vitro polymerisation of dihydroxyindoles to form synthetic eumelanins is explored up to its high mass limits, giving at the same time information on the polymerisation mode, whether it follows a stepwise pattern (being this the conclusion in our case) or a staking sequencing of small‐sized entities. It also highlighted the influence of the N‐methyl substituent on the polymerization process; this opens the way to the production of N‐functionalized, synthetic eumelanin‐inspired soft materials, for possible future technological applications. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of the major urinary metabolites in man of seven synthetic cannabinoids of the aminoalkylindole type present as adulterants in ‘herbal mixtures’ using LC‐MS/MS techniques
Authors: Hutter M. , Broecker S. , Kneisel S. , Auwärter V.
Published: January 2012

Herbal mixtures, such as ‘Spice’, containing cannabimimetic compounds are easily available on the Internet and have become increasingly popular among people having to undergo urine drug testing, as these compounds are not detected by current immunochemical tests. For analysis of urine samples, knowledge of the main metabolites is necessary as the unchanged compounds are usually not found in urine after consumption. In this paper, the identification of the major metabolites of the currently most common seven synthetic cannabinoids is presented. Urine samples from patients of psychiatric facilities known to have consumed synthetic cannabinoids were screened by LC‐MS/MS and HR‐MS/MS techniques, and the major metabolites for each of the following synthetic cannabinoids were identified by their enhanced product ion spectra and accurate mass measurement: JWH‐018, JWH‐073, JWH‐081, JWH‐122, JWH‐210, JWH‐250 and RCS‐4. The major metabolic pathway is monohydroxylation either at the N‐alkyl side chain, the naphthyl moiety or the indole moiety. In addition, metabolites with carboxylated alkyl chains were identified for some of the compounds. These results facilitate the design of urine screening methods for detecting consumption of synthetic cannabinoids. Copyright © 2012 John Wiley & Sons, Ltd.
Towards a universal LC–MS screening procedure – can an LIT LC–MSn screening approach and reference library be used on a quadrupole‐LIT hybrid instrument?
Authors: Wissenbach Dirk K. , Meyer Markus R. , Weber Armin A. , Remane Daniela , Ewald Andreas H. , Peters Frank T. , Maurer Hans H.
Published: January 2012

In contrast to libraries with highly reproducible gas chromatography electron ionization mass spectra, current liquid chromatography (LC–MS) libraries are limited to specific instrument types. Therefore, the aim of the study was to prove whether a recently developed linear ion trap (LIT) LC–MSn screening approach and reference library can be transferred to an LC–MS/MS system with a quadrupole‐LIT hybrid mass analyzer using SmileMS, a sophisticated search algorithm. The LIT reference library was built with MS² and MS³ wideband spectra recorded on a ThermoFisher LXQ LIT with electrospray ionization in positive mode and full‐scan data‐dependent acquisition (DDA). Collision parameter optimizations, including different scan types and energies, were performed on an Applied Biosystems QTRAP 4000 system using electrospray ionization in positive mode and full‐scan DDA. Modified library sets were generated to improve the detection of a compound by the used search algorithm. Additionally, 100 authentic human urine samples were screened by both systems for proof of applicability. In the applicability study, 533 compounds were detected by the LXQ and 477 by the QTRAP system using enhanced product ion scan and a modified database. The presented data showed that the LIT screening approach and reference library could be used successfully on a QTRAP instrument with some limitations. These should be overcome by further optimizations regarding DDA settings for better sensitivity and further library modifications to reduce spectra mismatches. Copyright © 2012 John Wiley & Sons, Ltd.
Characterization of amino acid‐derived betaines by electrospray ionization tandem mass spectrometry
Authors: Naresh Chary V. , Dinesh Kumar Ch. , Vairamani M. , Prabhakar S.
Published: January 2012

Betaines belong to the naturally occurring osmoprotectants or compatible solutes present in a variety of plants, animals and microorganisms. In recent years, metabolomic techniques have been emerging as a fundamental tool for biologists because the constellation of these molecules and their relative proportions provide with information about the actual biochemical condition of a biological system. Therefore, identification and characterization of biologically important betaines are crucial, especially for metabolomic studies. Most of the natural betaines are derived from amino acids and related homologues. Although, theoretically, all the amino acids can be converted to corresponding betaines by simple methylation of the amine group, only a few of the amino acid‐derived betaines were fully characterized in the literature. Here, we report a combined electrospray ionization tandem and high‐resolution mass spectrometry study of all the betaines derived from amino acids, including the isomeric betaines. The decomposition pathway of protonated, sodiated and potassiated molecule ions that enable unambiguous characterization of the betaines including the isomeric betaines and overlapping ionic species of different betaines is distinctive. Copyright © 2012 John Wiley & Sons, Ltd.
Tandem mass spectrometry of poly(ethylene imine)s by electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI)
Authors: Altuntaş Esra , Knop Katrin , Tauhardt Lutz , Kempe Kristian , Crecelius Anna C. , Jäger Michael , Hager Martin D. , Schubert Ulrich S.
Published: January 2012

In this contribution, linear poly(ethylene imine) (PEI) polymers, which are of importance in gene delivery, are investigated in detail by using electrospray ionization‐quadrupole‐time of flight (ESI‐Q‐TOF) and matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF) mass spectrometry (MS). The analyzed PEIs with different end groups were synthesized using the polymerization of substituted 2‐oxazoline via a living cationic ring‐opening polymerization (CROP) and a subsequent hydrolysis under acidic conditions. The main goal of this study was to identify linear PEI polymers in a detailed way to gain information about their fragmentation pathways. For this purpose, a detailed characterization of three different linear PEIs was performed by using ESI‐Q‐TOF and MALDI‐TOF MS in combination with collision‐induced dissociation (CID) experiments. In ESI‐MS as well as MALDI‐MS analysis, the obtained spectra of PEIs resulted in fitting mass distributions for the investigated PEIs. In the tandem MS analysis, a 1,2‐hydride shift with a charge‐remote rearrangement via a four‐membered cyclic transition state, as well as charge‐induced fragmentation reactions, was proposed as the main fragmentation mechanisms according to the obtained fragmentation products from the protonated parent peaks. In addition, heterolytic and homolytic cleavages were proposed as alternative fragmentation pathways. Moreover, a 1,4‐hydrogen elimination was proposed to explain different fragmentation products obtained from the sodiated parent peaks. Copyright © 2012 John Wiley & Sons, Ltd.
Structural elucidation of diglycosyl diacylglycerol and monoglycosyl diacylglycerol from Streptococcus pneumoniae by multiple‐stage linear ion‐trap mass spectrometry with electrospray ionization
Authors: Tatituri Raju Venkata Veera , Brenner Michael B. , Turk John , Hsu Fong‐Fu
Published: January 2012

The cell wall of the pathogenic bacterium Streptococcus pneumoniae contains glucopyranosyl diacylglycerol (GlcDAG) and galactoglucopyranosyldiacylglycerol (GalGlcDAG). The specific GlcDAG consisting of vaccenic acid substituent at sn‐2 was recently identified as another glycolipid antigen family recognized by invariant natural killer T‐cells. Here, we describe a linear ion‐trap multiple‐stage (MSn) mass spectrometric approach towards structural analysis of GalGlcDAG and GlcDAG. Structural information derived from MSn (n = 2, 3) on the [M + Li]+ adduct ions desorbed by electrospray ionization affords identification of the fatty acid substituents, assignment of the fatty acyl groups on the glycerol backbone, as well as the location of double bond along the fatty acyl chain. The identification of the fatty acyl groups and determination of their regio‐specificity were confirmed by MSn (n = 2, 3) on the [M + NH4]+ ions. We establish the structures of GalGlcDAG and GlcDAG isolated from S. pneumoniae, in which the major species consists of a 16:1‐ or 18:1‐fatty acid substituent mainly at sn‐2, and the double bond of the fatty acid is located at ω‐7 (n‐7). More than one isomers were found for each mass in the family. This mass spectrometric approach provides a simple method to achieve structure identification of this important lipid family that would be very difficult to define using the traditional method. Copyright © 2012 John Wiley & Sons, Ltd.
Direct screening of herbal blends for new synthetic cannabinoids by MALDI‐TOF MS
Authors: Gottardo Rossella , Chiarini Anna , Dal Prà Ilaria , Seri Catia , Rimondo Claudia , Serpelloni Giovanni , Armato Ubaldo , Tagliaro Franco
Published: January 2012

Since 2004, a number of herbal blends containing different synthetic compounds mimicking the pharmacological activity of cannabinoids and displaying a high toxicological potential have appeared in the market. Their availability is mainly based on the so‐called “e‐commerce”, being sold as legal alternatives to cannabis and cannabis derivatives. Although highly selective, sensitive, accurate, and quantitative methods based on GC–MS and LC–MS are available, they lack simplicity, rapidity, versatility and throughput, which are required for product monitoring. In this context, matrix‐assisted laser desorption ionization‐time of flight mass spectrometry (MALDI‐TOF MS) offers a simple and rapid operation with high throughput. Thus, the aim of the present work was to develop a MALDI‐TOF MS method for the rapid qualitative direct analysis of herbal blend preparations for synthetic cannabinoids to be used as front screening of confiscated clandestine preparations. The sample preparation was limited to herbal blend leaves finely grinding in a mortar and loading onto the MALDI plate followed by addition of 2 µl of the matrix/surfactant mixture [α‐cyano‐4‐hydroxy‐cinnamic acid/cetyltrimethylammonium bromide (CTAB)]. After drying, the sample plate was introduced into the ion source for analysis. MALDI‐TOF conditions were as follows: mass spectra were analyzed in the range m/z 150–550 by averaging the data from 50 laser shots and using an accelerating voltage of 20 kV.

The described method was successfully applied to the screening of 31 commercial herbal blends, previously analyzed by GC–MS. Among the samples analyzed, 21 contained synthetic cannabinoids (namely JWH‐018, JWH‐073, JWH‐081, JWH‐250, JWH‐210, JWH‐019, and AM‐694).

All the results were in agreement with GC–MS, which was used as the reference technique. Copyright © 2012 John Wiley & Sons, Ltd.
Dial M for mentor: Reflections on mentoring in film, television, and literature
Authors: Schuttler Richard
Published: January 2012

By Jonathan Gravells and Susan Wallace

Charlotte, NC: Information Age Publishing Company. 2011. 148 pp. ISBN: 978‐1‐6173‐5429‐8. $85.99 Hardcover, $45.99 Paperback

Reviewed by Richard Schuttler, PhD
Diversity: A normative study for education, health care, administrative, and manufacturing industries
Authors: Andrulis Richard S. , Ligon Ginamarie S. , Zongrone Bianca M.
Published: January 2012

An organization that encourages diversity through its practices and policies creates a favorable climate affecting a broad range of organizational attitudes, perceptions, and performance. This study provides insight into where organizations are today in achieving diversity in their workforce.
Organizational cultures: Obstacles to women in the UK construction industry
Authors: Worrall Lisa
Published: January 2012

The global economic downturn coupled with recent changes in UK law have led to a sizable reduction in public sector funding. As a result, both public and private sector organizations are under greater pressure to provide evidence of their activities in promoting equality and diversity in their use of public sector funds. This requirement poses a particular challenge for the UK construction industry, which remains largely White male dominated. Empirical data gathered from a series of semistructured questionnaires and focus groups that have received managerial and soft skills training are analyzed and discussed in this article in an effort to establish the organizational cultural obstacles that women face in working in the UK construction industry. The findings outline that White male‐dominated organizational cultures, inflexible work practices, and a lack of supportive networks serve as obstacles to women in the UK construction industry. This study concludes with recommendations for the expansion of training opportunities for women to encourage workforce diversity within the UK construction industry.