bluuebunny/crossref_metadata_2025 huggingface dataset:
A multi‐method field experiment to determine local groundwater flow in a glacier forefield
Authors: Kobierska Florian , Jonas Tobias , Griessinger Nena , Hauck Christian , Huxol Stephan , Bernasconi Stefano M.
Published: February 2014

We implemented multiple independent field techniques to determine the direction and velocity of groundwater flow at a specific stream reach in a glacier forefield. Time‐lapse experiments were conducted using two electrical resistivity tomography (ERT) lines installed in a cross pattern. A circular array of groundwater tubes was also installed to monitor groundwater flow via discrete salt injections. Both inter‐borehole and ERT results confirmed this stream section as a losing reach and enabled quantification of the flow direction. Both techniques yielded advection velocities varying between 5.7 and 21.8 m/day. Estimates of groundwater flow direction and velocity indicated that groundwater infiltrates from the stream nearby and not from the adjacent lateral moraine. Groundwater age estimated from radon concentration measurements supported this hypothesis. Despite uncertainties inherent to each of the methods deployed, the combination of multiple field techniques allowed drawing consistent conclusions about local groundwater flow. We thus regard our multi‐method approach as a reliable way to characterize the two‐dimensional groundwater flow at sites where more invasive groundwater investigation techniques are difficult to carry out and local heterogeneities can make single measurements unreliable. Copyright © 2014 John Wiley & Sons, Ltd.
Dysregulated Fear in Toddlerhood Predicts Kindergarten Social Withdrawal through Protective Parenting
Authors: Kiel Elizabeth J. , Buss Kristin A.
Published: February 2014

Two recent advances in the study of fearful temperament (behavioural inhibition) include the validation of dysregulated fear as a temperamental construct that more specifically predicts later social withdrawal and anxiety, and the use of conceptual and statistical models that place parenting as a mechanism of development from temperament to these outcomes. The current study further advances these areas by examining whether protective parenting mediated the relation between dysregulated fear in toddlerhood and social withdrawal in kindergarten. Participants included 93 toddlers and their mothers, who engaged in laboratory tasks assessing traditional fearful temperament, dysregulated fear, and protective parenting. When children reached kindergarten, they returned to the laboratory for a multimethod assessment of social withdrawal. Results confirmed the hypothesis that dysregulated fear predicted social withdrawal through protective parenting, and this occurred above and beyond the effect of traditional fearful temperament. These findings bolster support for the use of dysregulated fear as a temperamental construct related to, but perhaps more discerning of risk than traditionally measured fearful temperament/behavioural inhibition and highlight the importance of transactional influences between the individual and the caregiving environment in the development of social withdrawal. Copyright © 2014 John Wiley & Sons, Ltd.
Shyness, Child–Teacher Relationships, and Socio‐Emotional Adjustment in a Sample of Italian Preschool‐Aged Children
Authors: Sette Stefania , Baumgartner Emma , Schneider Barry H.
Published: February 2014

The purpose of the present study was to examine the moderating role of child–teacher relationship quality (i.e., closeness, conflict, and dependence) in the association between children's shyness and indices of socio‐emotional adjustment and maladjustment. The participants were Italian preschool children (63 boys; 66 girls) and two lead teachers per classroom (N = 7 classrooms). In each classroom, one teacher, randomly selected, evaluated the quality of the child–teacher relationship; the other evaluated children's social competence and maladjustment. Peer liking was measured using a sociometric procedure. Parents provided an assessment of their children's shyness. Shyness was positively related to teacher‐reported rejection and internalizing problems whereas shyness was negatively associated with closeness and conflict with teachers. Moreover, closeness, conflict, and dependence in the child–teacher relationship moderated the links between children shyness and indices of preschool social competence and maladjustment. For example, among children with low levels of closeness, shyness was negatively associated with teacher‐reported social competence and positively related to teacher‐reported peer rejection. At very high levels of dependence, there was a negative relation between shyness and social competence. The findings suggest that a positive child–teacher relationship may be a protective factor in avoiding social maladjustment in Italian scuole d'infanzia, where most pupils remain with the same teacher for 3 years. Copyright © 2014 John Wiley & Sons, Ltd.
Lack of synergistic interaction between the two mechanisms of action of tapentadol in gastrointestinal transit
Authors: Cowan A. , Raffa R.B. , Tallarida C.S. , Tallarida R.J. , Christoph T. , Schröder W. , Tzschentke T.M.
Published: February 2014

Background

A multi‐mechanistic approach offers potential enhancement of analgesic efficacy, but therapeutic gain could be offset by an increase in adverse events. The centrally acting analgesic tapentadol [(–)‐(1R,2R)‐3‐(3‐dimethylamino‐1‐ethyl‐2‐methyl‐propyl)‐phenol hydrochloride] combines μ‐opioid receptor (MOR) agonism and neuronal noradrenaline reuptake inhibition (NRI), both of which contribute to its analgesic effects. Previously, isobolographic analysis of occupation‐effect data and a theoretically equivalent methodology determining interactions from the effect scale demonstrated pronounced synergistic interaction between the two mechanisms of action of tapentadol in two models of antinociception (low‐intensity tail‐flick and spinal nerve ligation). The present study investigated the nature of interaction of the two mechanisms on a surrogate measure for gastrointestinal adverse effect (inhibition of gastrointestinal transit).

Methods

Dose–response curves were generated in rats for tapentadol alone or in combination with the opioid receptor antagonist, naloxone, or the α2‐adrenoceptor antagonist, yohimbine, to reveal the effect of tapentadol based upon MOR agonism, NRI, and combined mechanisms.

Results

The dose–effect curve of tapentadol was shifted to the right by both antagonists, thereby providing data to distinguish between MOR agonism and NRI. Analysis revealed a simple additive interaction between the two mechanisms on this endpoint, in contrast to the synergistic interaction previously demonstrated for antinociception.

Conclusions

We believe this is the first published evaluation of mechanistic interaction for a surrogate measure of adverse effect of a single compound with two mechanisms of action, and the results suggest that there is a greater separation between the analgesic and gastrointestinal effects of tapentadol than expected based upon its analgesic efficacy.
A flexible wide‐field FLIM endoscope utilising blue excitation light for label‐free contrast of tissue
Authors: Sparks Hugh , Warren Sean , Guedes Joana , Yoshida Nagisa , Charn Tze Choong , Guerra Nadia , Tatla Taranjit , Dunsby Christopher , French Paul
Published: February 2014

Fluorescence lifetime imaging (FLIM) has previously been shown to provide contrast between normal and diseased tissue. Here we present progress towards clinical and preclinical FLIM endoscopy of tissue autofluorescence, demonstrating a flexible wide‐field endoscope that utilised a low average power blue picosecond laser diode excitation source and was able to acquire ∼mm‐scale spatial maps of autofluorescence lifetimes from fresh ex vivo diseased human larynx biopsies in ∼8 seconds using an average excitation power of ∼0.5 mW at the specimen. To illustrate its potential for FLIM at higher acquisition rates, a higher power mode‐locked frequency doubled Ti:Sapphire laser was used to demonstrate FLIM of ex vivo mouse bowel at up to 2.5 Hz using 10 mW of average excitation power at the specimen. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)
Fabrication of a heparin–PVA complex hydrogel for application as a vascular access
Authors: Negishi Jun , Nam Kwangwoo , Kimura Tsuyoshi , Hashimoto Yoshihide , Funamoto Seiichi , Higami Tetsuya , Fujisato Toshiya , Kishida Akio
Published: February 2014

A high hydrostatic pressure method, which can apply over 600 MPa pressure was employed for preparing a hydrogel of poly(vinyl alcohol) (PVA) loaded with heparin. The aim of this study was to fabricate a heparin–PVA hydrogel conduit and evaluate its potential for vascular access. Heparin–PVA complex hydrogel showed suppressed heparin release and prevented clot formation, depending on the molecular weight of the PVA. Strength of the hydrogel conduit was increased by embedding a Dacron® mesh between two PVA layers. The tubular heparin–PVA complex hydrogel displayed a burst pressure of 750 mmHg. The tubular heparin–PVA complex hydrogel did not show any occlusion or burst for 2 weeks after implantation, implying that this heparin–PVA complex hydrogel shows high potential for use as a vascular access. This is the first report on the preparation of a multilayered PVA hydrogel with heparin embedded on one side only. The proposed approach could be expanded to the fabrication of various biomaterials for specific purposes. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1426–1433, 2014.
Metabolic Pathways Related to Oxidative Stress in Patients With Hemoglobin H Disease and Iron Overload
Authors: Chiou Shyh‐Shin , Tsao Chao‐Jung , Tsai Shih‐Meng , Wu Ye‐Ru , Liao Yu‐Mei , Lin Pei‐Chin , Tsai Li‐Yu
Published: February 2014

Background

Iron overload is a major complication in patients with hemoglobin H (Hb H) disease and causes damage of tissues.

Methods

We investigated 26 Hb H patients and 75 controls to evaluate their oxidative stress and antioxidant statuses.

Results

There were significantly increased levels of superoxide anion in leucocytes, nitrite (N), and malondialdehyde (MDA) in plasma, and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx) and oxidized glutathione (GSSG) in erythrocytes, decreased levels of nitrate (N) and vitamin C in plasma, and reduced glutathione (GSH) in erythrocytes, in addition to the abnormal iron status in the patients when compared with those in the controls. Meanwhile, levels of serum ferritin were positively correlated with serum iron, plasma MDA, and erythrocyte SOD in the patients. In addition, the activities of SOD were positively correlated with those of GPx and GRx, and the levels of GSSG and MDA, but negatively correlated with those of GSH. Furthermore, the levels of MDA were negatively correlated those of vitamin C.

Conclusions

These results demonstrate the presence of oxidative stress and decreased levels of antioxidants; moreover, the related metabolic antioxidant pathway is active in Hb H patients with iron overload.
Complement‐Dependent Cytotoxicity (CDC) to Detect Anti‐HLA Antibodies: Old but Gold
Authors: Saito Patrícia Keiko , Yamakawa Roger Haruki , da Silva Pereira Lucieni Christina Marques , da Silva Junior Waldir Veríssimo , Borelli Sueli Donizete
Published: February 2014

Background

The criterion (gold) standard to detect anti‐human leukocyte antigen (HLA) antibodies is the complement‐dependent cytotoxicity (CDC) assay. Recently, more sensitive methods have been used for the same purpose.

Methods

This study analyzed 70 serum samples of patients with end‐stage renal disease using CDC, CDC with the addition of anti‐human globulin (CDC‐AHG), CDC with the addition of dithiothreitol (CDC‐DTT), and the recent solid‐phase immunoassay (SPI; Labscreen PRA) to detect anti‐HLA antibodies.

Results

Mean percent panel reactive antibodies (PRA) detected by SPI was 37.5% (±34.2) higher than the values detected by the other methods. Comparative analyses revealed significant difference between CDC and CDC‐AHG, and between CDC and SPI (P< 0.0001), but not between CDC‐AHG and SPI (P= 0.8026).

Conclusion

Although the CDC‐AHG method is “old,” its performance to detect anti‐HLA antibodies in the samples analyzed was comparable to the SPI in the evaluation of percent class I PRA.
Association of Novel Gene Polymorphisms RRM1 −756T>C and −269 C>A With Breast Cancer
Authors: Chen Dar‐Ren , Chuang Chun‐Yi , Wu Buor‐Chang , Yang Shun‐Fa , Peng Yu‐Hsien , Tsai Hsiu‐Ting
Published: February 2014

Background

Genetic variants are reported to play an important role in the susceptibility of breast cancer. Ribonucleotide reductase 1 (RRM1) is suggested to play an essential role in the regulation of cancer development. The purpose of this study was to identify novel gene polymorphisms of RRM1 −756T>C and RRM1 −269 C>A specific to patients with breast cancer and healthy controls.

Methods

A total of 833 subjects, including 321 healthy controls and 512 patients with breast cancer, were recruited in this study. Allelic discrimination of RRM1 −756T>C (rs11030919) and RRM1 −269C>A (rs12806698) polymorphisms of the RRM1 gene was assessed with the real‐time polymerase chain reaction.

Results

The adjusted odds ratios and 95% confidence intervals were 1.20 (0.71–2.04) and 1.10 (0.65–1.86) to have breast cancer among individuals with CC alleles of RRM1 −756T>C and individuals with AA alleles of RRM1 −269C>A gene polymorphism, respectively, compared to individuals having wild type of RRM1 gene polymorphisms. Also, there was no significant genetic interaction effect on the susceptibility of breast cancer and nonassociation between genetic polymorphisms and clinical statuses of breast cancer.

Conclusion

Gene polymorphisms of RRM1 −756T>C and RRM1 −269C>A may be not an important factor for the susceptibility of breast cancer.
Fluorescence Immunoassay of Human D‐dimer in Whole Blood
Authors: Kim Tae Kyum , Oh Sang Wook , Mok Young Joon , Choi Eui Yul
Published: February 2014

Background

D‐dimer is a widely used biomarker for the initial clinical assessment of suspected deep vein thrombosis and pulmonary embolism. Here, we presented a new fluorescence (FL) D‐dimer assay system, which was developed with a platform of point‐of‐care test (POCT) for clinical applications.

Methods

Whole blood was mixed with FL‐labeled anti‐D‐dimer detector antibody, and then loaded onto a disposable cartridge. After 12 min of incubation, the FL intensity was acquired by scanning of test cartridge and converted as level of D‐dimer in a laser FL scanner. The analytical performance of FL immunoassay was evaluated by linearity, recovery, and precision tests. The comparability of the developed assay was examined with automated reference methods.

Results

The FL assay system showed a good linearity, and the analytical mean recovery of control was 103% in a dynamic working range. The imprecision of intra‐ and inter‐as‐say of coefficient of variations from assay system was less than 8%. The developed FL assay system showed strong correlation with two automated reference assays, Vidas D‐dimer (r = 0.973) and Stalia D‐dimer (r = 0.971).

Conclusion

The new FL immunoassay for D‐dimer is a user‐friendly, precise, and reproducible platform of POCT in whole blood.
A new strategy for enhancement of poly‐γ‐glutamic acid production by multiple physicochemical stresses in Bacillus licheniformis
Authors: Wei Xuetuan , Tian Guangming , Ji Zhixia , Chen Shouwen
Published: February 2014

BACKGROUND

The physicochemical stress‐induced bioprocess is an efficient strategy for enhancement of the production of microbial metabolites, but multiple physicochemical stresses have not applied in poly‐γ‐glutamic acid (γ‐PGA) production.

RESULTS

The effects of multiple physicochemical stresses on the production and synthetase genes transcription of γ‐PGA were investigated in Bacillus licheniformis WX‐02. Under heat stress stimulated at 50 °C, osmotic stress induced by 3% KCl, and alkaline stress mediated by pH 8.5, γ‐PGA yields increased by 66%, 106% and 133%, respectively, and the transcription levels of γ‐PGA synthetase gene PgsC were improved 3.1‐fold, 3.6‐fold and 5.4‐fold compared with the control. Heat and osmotic stress also induced the up‐regulation of another γ‐PGA synthetase gene of PgsB with 1.4‐fold and 4.3‐fold increase, respectively. By combined application of heat and pH stress, the maximum γ‐PGA yield reached 29.34 g L−1, 185% higher than the control.

CONCLUSION

This study provided a novel strategy to enhance γ‐PGA yield by physicochemical stresses treatment, and the possible mechanism was also determined. The stress‐mediated strategy can be easily applied in γ‐PGA production at large scale. © 2014 Society of Chemical Industry
MRI of the carotid artery at 7 Tesla: Quantitative comparison with 3 Tesla
Authors: Koning Wouter , de Rotte Alexandra A.J. , Bluemink Johanna J. , van der Velden Tijl A. , Luijten Peter R. , Klomp Dennis W.J. , Zwanenburg Jaco J.M.
Published: February 2014

Purpose

To evaluate the 7 Tesla (T) MRI of the carotid arteries, as quantitatively compared with 3T.

Materials and Methods

The 7T MRI of the carotid arteries was performed in six healthy subjects and in two patients with carotid stenosis. The healthy group was scanned at 3T and at 7T, using current coil setups at both field strengths. T1 and T2 values of the normal carotid vessel wall were assessed at both field strengths. B1+ maps and signal to noise ratio (SNR) maps were obtained, as well as T1 weighted images with a resolution as high as 0.4 × 0.4 × 1.5 mm3.

Results

The T1 of the normal carotid vessel wall was found to be 1227 ± 47 ms at 3T and 1628 ± 130 ms at 7T, while a T2 of 55 ± 11 ms at 3T and 46 ± 4 ms at 7T was found. A twofold average gain in SNR at the carotid arteries was found with 7T. T1 weighted images showed an increased SNR at 7T for all subjects.

Conclusion

Evaluation between 3T and 7T carotid MRI with optimized setups at both field strengths showed improved SNR at 7T, an increase in vessel wall T1 and a decrease in vessel wall T2. J. Magn. Reson. Imaging 2015;41:773–780. © 2014 Wiley Periodicals, Inc.
Highly efficient respiratory motion compensated free‐breathing coronary mra using golden‐step Cartesian acquisition
Authors: Prieto Claudia , Doneva Mariya , Usman Muhammad , Henningsson Markus , Greil Gerald , Schaeffter Tobias , Botnar Rene M.
Published: February 2014

Purpose

To develop an efficient 3D affine respiratory motion compensation framework for Cartesian whole‐heart coronary magnetic resonance angiography (MRA).

Materials and Methods

The proposed method achieves 100% scan efficiency by estimating the affine respiratory motion from the data itself and correcting the acquired data in the reconstruction process. For this, a golden‐step Cartesian sampling with spiral profile ordering was performed to enable reconstruction of respiratory resolved images at any breathing position and with different respiratory window size. Affine motion parameters were estimated from image‐based registration of 3D undersampled respiratory resolved images reconstructed with iterative SENSE and motion correction was performed directly in the reconstruction using a multiple‐coils generalized matrix formulation method. This approach was tested on healthy volunteers and compared against a conventional diaphragmatic navigator‐gated acquisition using quantitative and qualitative image quality assessment.

Results

The proposed approach achieved 47 ± 12% and 59 ± 6% vessel sharpness for the right (RCA) and left (LAD) coronary arteries, respectively. Also, good quality visual scores of 2.4 ± 0.74 and 2.44 ± 0.86 were observed for the RCA and LAD (scores from 0, no to 4, excellent coronary vessel delineation). A not statically significant difference (P = 0.05) was found between the proposed method and an 8‐mm navigator‐gated and tracked scan, although scan efficiency increased from 61 ± 10% to 100%.

Conclusion

We demonstrate the feasibility of a new 3D affine respiratory motion correction technique for Cartesian whole‐heart CMRA that achieves 100% scan efficiency and therefore a predictable acquisition time. This approach yields image quality comparable to that of an 8‐mm navigator‐gated acquisition with lower scan efficiency. Further evaluation of this technique in patients is now warranted to determine its clinical use. J. Magn. Reson. Imaging 2015;41:738–746. © 2014 Wiley Periodicals, Inc.
The effect of image‐guided radiation therapy on the margin between the clinical target volume and planning target volume in lung cancer
Authors: Liang Jun , Li Minghui , Zhang Tao , Han Wei , Chen Dongfu , Hui Zhouguang , Lv Jima , Zhang Zhong , Zhang Yin , Zhang Liansheng , Zheng Rong , Dai Jianrong , Wang Luhua
Published: February 2014

Introduction

This study aimed to evaluate the effect of image‐guided radiation therapy (IGRT) on the margin between the clinical target volume (CTV) and planning target volume (PTV) in lung cancer.

Methods

The CTV and PTV margin were determined in three dimensions by four radiation oncologists using a standard method in 10 lung cancer patients, and compared to consensus values. Transfer error was measured using a rigid phantom containing gold markers. Systematic error () and random error () set up errors were calculated in three dimensions from pre‐treatment and post‐treatment cone beam CT scans. Finally, the margin between the CTV and PTV was corrected for set up error and calculated.

Results

The margins between the CTV and PTV with IGRT (and without IGRT) were 0.88 cm (0.96 cm), 0.99 cm (1.08 cm) and 1.28 cm (1.82 cm) in the anterior and posterior (AP), left and right (LR) and superior and inferior (SI) directions, respectively. Images from two other patients verified the validity of the corrected margin. The target delineation errors of the radiation oncologists are considered to be the largest compared with the set up errors. The application of IGRT reduced the set up errors and the margins between CTV and PTV.

Conclusions

The delineation errors of radiation oncologists are the most important factor to consider for the margin between CTV and PTV for lung cancer. IGRT can reduce the margins by reducing the set up errors, especially in the SI direction. Further research is required to assess whether the reduction in the margin is solely based on set up errors.
A comparison of intravenous and intradiscal delivery of multipotential stem cells on the healing of injured intervertebral disk
Authors: Tam Vivian , Rogers Ian , Chan Danny , Leung Victor Y. L. , Cheung Kenneth M. C.
Published: February 2014

A major hurdle of cellular therapy for biological treatment of intervertebral disk (IVD) degeneration is the delivery method where current delivery methods are limited to intradiscal injection which can potentially cause further degeneration. Recent studies indicated that multipotential stem cells (MPSCs) from human umbilical cord blood home to injured sites and induce local therapeutic changes, thereby potentially addressing the drawbacks of direct delivery. We tested the effects of these cells on injured IVD using a mouse model of puncture‐induced degeneration via two delivery methods. Caudal IVD underwent needle puncture, and MPSCs were injected indirectly (intravenously), or directly (intradiscally) into the nucleus pulposus. IVD were harvested for histological, gene and protein analysis after 14 weeks. Our finding showed limited homing ability of the MPSCs. However, regardless of delivery method, no engraftment or expansion of MPSCs was observed at the injured site. Contrasting to direct injection, intravenous injection neither improved the degeneration status, nor preserve disk height, however, both delivery methods increased glycosaminoglycan (GAG) protein and Acan gene expression relative to controls, suggesting possible paracrine effects. Identifying the mechanisms by which MPSCs act on endogenous IVD cells would provide insights into the potential of these cells to treat IVD injuries and degeneration. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:819–825, 2014.
A multivariate model for the meta‐analysis of study level survival data at multiple times
Authors: Jackson Dan , Rollins Katie , Coughlin Patrick
Published: February 2014

Motivated by our meta‐analytic dataset involving survival rates after treatment for critical leg ischemia, we develop and apply a new multivariate model for the meta‐analysis of study level survival data at multiple times. Our data set involves 50 studies that provide mortality rates at up to seven time points, which we model simultaneously, and we compare the results to those obtained from standard methodologies. Our method uses exact binomial within‐study distributions and enforces the constraints that both the study specific and the overall mortality rates must not decrease over time. We directly model the probabilities of mortality at each time point, which are the quantities of primary clinical interest. We also present I2 statistics that quantify the impact of the between‐study heterogeneity, which is very considerable in our data set. © 2014 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.
Māori Traditional Knowledge and New Zealand Patent Law: The 2013 Act and the Dawn of a New Era?
Authors: Lai Jessica C.
Published: February 2014

In August 2013, New Zealand passed a new Patents Act that codified the ability of the Commissioner to refuse to grant patents for inventions which are: (1) derived from Māori TK or indigenous plants or animals; and (2) the commercial exploitation of which is likely to be contrary to Māori values. As discussed in this article, for many reasons patents are seldom of interest to indigenous peoples as a means to protect their traditional knowledge (TK). On the contrary, the patent system has predominantly been viewed by indigenous peoples as a means for third parties to propertise their TK. The new mechanism in the 2013 Act may not make patents more attractive for Māori TK, but addresses concerns regarding third‐party patenting of inventions related to Māori TK and indigenous species. This article examines this new mechanism and compares it to the situation under the prior 1953 Act. It concludes that, while many questions remain open regarding the exact application of the 2013 Act, together with the Trade Marks Act 2002 (which contains similar provisions preventing the registration of marks offensive to the Māori), New Zealand has shown that it is willing to be innovative with its intellectual property laws in order to address the concerns of its indigenous peoples.
Complete 1H NMR assignments of pyrrolizidine alkaloids and a new eudesmanoid from Senecio polypodioides
Authors: Villanueva‐Cañongo Claudia , Pérez‐Hernández Nury , Hernández‐Carlos Beatriz , Cedillo‐Portugal Ernestina , Joseph‐Nathan Pedro , Burgueño‐Tapia Eleuterio
Published: February 2014

Chemical investigation of the aerial parts of Senecio polypodioides lead to the isolation of the new eudesmanoid 1β‐angeloyloxyeudesm‐7‐ene‐4β,9α‐diol (1) and the known dirhamnosyl flavonoid lespidin (3), while from roots, the known 7β‐angeloyloxy‐1‐methylene‐8α‐pyrrolizidine (5) and sarracine N‐oxide (6), as well as the new neosarracine N‐oxide (8), were obtained. The structure of 1 and 8 was elucidated by spectral means. Complete assignments of the 1H NMR data for 5, 6, sarracine (7), and 8 were made using one‐dimensional and two‐dimensional NMR experiments and by application of the iterative full spin analysis of the PERCH NMR software. Copyright © 2014 John Wiley & Sons, Ltd.
On the accuracy of the GIAO‐DFT calculation of 15N NMR chemical shifts of the nitrogen‐containing heterocycles – a gateway to better agreement with experiment at lower computational cost
Authors: Samultsev Dmitry O. , Semenov Valentin A. , Krivdin Leonid B.
Published: February 2014

The main factors affecting the accuracy and computational cost of the gauge‐independent atomic orbital density functional theory (GIAO‐DFT) calculation of 15N NMR chemical shifts in the representative series of key nitrogen‐containing heterocycles – azoles and azines – have been systematically analyzed. In the calculation of 15N NMR chemical shifts, the best result has been achieved with the KT3 functional used in combination with Jensen's pcS‐3 basis set (GIAO‐DFT‐KT3/pcS‐3) resulting in the value of mean absolute error as small as 5 ppm for a range exceeding 270 ppm in a benchmark series of 23 compounds with an overall number of 41 different 15N NMR chemical shifts. Another essential finding is that basically, the application of the locally dense basis set approach is justified in the calculation of 15N NMR chemical shifts within the 3–4 ppm error that results in a dramatic decrease in computational cost. Based on the present data, we recommend GIAO‐DFT‐KT3/pcS‐3//pc‐2 as one of the most effective locally dense basis set schemes for the calculation of 15N NMR chemical shifts. Copyright © 2014 John Wiley & Sons, Ltd.
On the accuracy of T1 mapping: Searching for common ground
Authors: Stikov Nikola , Boudreau Mathieu , Levesque Ives R. , Tardif Christine L. , Barral Joëlle K. , Pike G. Bruce
Published: February 2014

Purpose

There are many T1 mapping methods available, each of them validated in phantoms and reporting excellent agreement with literature. However, values in literature vary greatly, with T1 in white matter ranging from 690 to 1100 ms at 3 Tesla. This brings into question the accuracy of one of the most fundamental measurements in quantitative MRI. Our goal was to explain these variations and look into ways of mitigating them.

Theory and Methods

We evaluated the three most common T1 mapping methods (inversion recovery, Look‐Locker, and variable flip angle) through Bloch simulations, a white matter phantom and the brains of 10 healthy subjects (single‐slice). We pooled the T1 histograms of the subjects to determine whether there is a sequence‐dependent bias and whether it is reproducible across subjects.

Results

We found good agreement between the three methods in phantoms, but poor agreement in vivo, with the white matter T1 histogram peak in healthy subjects varying by more than 30% depending on the method used. We also found that the pooled brain histograms displayed three distinct white matter peaks, with Look‐Locker consistently underestimating, and variable flip angle overestimating the inversion recovery T1 values. The Bloch simulations indicated that incomplete spoiling and inaccurate B1 mapping could account for the observed differences.

Conclusion

We conclude that the three most common T1 mapping protocols produce stable T1 values in phantoms, but not in vivo. To improve the accuracy of T1 mapping, we recommend that sites perform in vivo validation of their T1 mapping method against the inversion recovery reference method, as the first step toward developing a robust calibration scheme. Magn Reson Med 73:514–522, 2015. © 2014 Wiley Periodicals, Inc.
A randomized trial of a prenatal genetic testing interactive computerized information aid
Authors: Yee Lynn M. , Wolf Michael , Mullen Rebecca , Bergeron Ashley R. , Cooper Bailey Stacy , Levine Robert , Grobman William A.
Published: February 2014

Objective

The aim of this study was to determine whether an interactive computer program could improve patient knowledge regarding genetic screening and diagnostic concepts.

Methods

In this randomized trial, women 6–26 weeks' gestation were assigned to standard care with provider‐based counseling or to augmented counseling with an interactive computer program. The computer‐based tool conveyed information about genetic testing options. Women were administered a 23‐item test of content knowledge immediately and 2–4 weeks after exposure. Test scores were compared between groups at both points using T‐tests.

Results

A total of 150 women were randomized equally between groups. Groups were similar with regard to demographic characteristics. Women randomized to the interactive tool correctly answered a significantly greater proportion of questions than those who received standard counseling (69.4% ± 14.2% vs. 46.0% ± 15.2%, p < 0.001) on the immediate questionnaire. One hundred and twenty‐three (82%) participants participated in the follow‐up test. Women randomized to the tool continued to correctly answer a significantly greater proportion of questions (60.6% ± 16% vs. 49.7% ± 18.9%, p = 0.001). Education, health literacy, electronic health literacy, and other discussions with providers were not associated with a differential benefit from the educational intervention.

Conclusion

A patient‐directed interactive computer program may help providers to convey relevant information about genetic screening and diagnostic concepts. © 2014 John Wiley & Sons, Ltd.
Surface topology caused by dislocations in polar, semipolar, and nonpolar InGaN/GaN heterostructures
Authors: Schade L. , Wernicke T. , Raß J. , Ploch S. , Weyers M. , Kneissl M. , Schwarz U. T.
Published: February 2014

The impact of dislocations on surface topology as well as on quantum well emission in c‐plane, semipolar, and nonpolar InGaN/GaN heterostructures is being analyzed by micro‐photoluminescence and white‐light‐interferometry. V‐pits with (101) and (10) side facets are identified in a (102) semipolar heterostructure. Hillocks formed by spiral growth around screw dislocations change from hexagonal to triangular to rectangular shape in polar, semipolar, and nonpolar heterostructures, respectively, reflecting the symmetry of the individual surface. The emission in semipolar quantum wells, grown homoepitaxially on bulk GaN substrates, show dark stripes aligned with misfit dislocations. For (112) and (201) orientation, these dark stripes are perpendicular and parallel, respectively, to surface striation.
Thermodynamic and kinetic aspects of AlN crystal formation on (0001)Al2O3 surface by ammonia MBE
Authors: Malin Timur , Mansurov Vladimir , Galitsyn Yury , Zhuravlev Konstantin
Published: February 2014

Influence of temperature on AlN formation on (0001) Al2O3 surface under ammonia flux (nitridation process) has been investigated by high‐energy electron diffraction. A significant temperature dependence of AlN formation rate in the temperature range of 850‐940 °C has been found whereas the formation rate is almost constant at temperatures higher than 940 °C. A kinetic scheme of the surface reactions is developed. The values of kinetic constants for the scheme at the low temperature range are found: k1P=6×104exp(‐1.5eV/kT), k2=7×1019exp (‐5.3eV/kT), k3=3×1013exp(‐4eV/kT). For the high temperature range the AlN formation process is described as a surface phase transition in AlN lattice gas. Parameters of lateral interaction between filled AlN cells are determined and the critical temperature of the phase transition is found (Tc=795 °C). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐resolved electroabsorption measurement of carrier velocity in inverted polarity In1‐xGax N/GaN heterostructures due to internal electric fields
Authors: Connelly Blair C. , Gallinat Chad S. , Woodward Nathaniel T. , Enck Ryan W. , Metcalfe Grace D. , Tompkins Randy , Jones Kenneth A. , Shen Hongen , Wraback Michael
Published: February 2014

Carrier transport measurements were made in a c ‐plane inverted‐polarity n ‐GaN/i ‐In1–xGax N/p ‐GaN heterostructure with a 200 nm thick In1–xGax N layer using ultrafast spectroscopy techniques. Time‐domain THz measurements indicate that the direction of electron transport is dominated by drift towards the n ‐GaN layer. Time‐resolved electroabsorption measurements were used to determine carrier velocities by monitoring the change in transmission of a probe beam tuned to the In1‐xGax N absorption edge due to the transport of photogenerated carriers under the built‐in internal electric field. Carrier transit times associated with screening of the electroabsorption are resolved at the lowest injection level. The signal rise time shows two distinct time scales, which correspond to an electron velocity of 3.3 ± 0.5 x 107 cm/s and a hole velocity of 6.7 ± 0.3 x 106 cm/s in an internal electric field of ∼150 kV/cm. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier trapping induced abnormal temperature dependent photoluminescence properties of novel sandwiched structure InGaN quantum wells
Authors: He Juan , Li Ding , Rajabi K. , Yang Wei , Liu Lei , Hu Xiaodong
Published: February 2014

A dual‐wavelength LED sample with novel sandwiched structure in high‐In‐content MQWs is studied by temperature dependent photoluminescence (TDPL) and the abnormal temperature dependence of emission intensity is obtained. The novel MQWs structure which contains staggered quantum wells and an ultra‐thin InN interlayer in the wells shows better luminescence property than the reference sample which has conventional quantum wells. Under 325 nm continuous wave laser excitation the LED sample of novel structure exhibits unexpected increasing luminescence intensity as temperature goes up from 140 K to 220 K and reaches its maximum at 220 K. This could be attributed to (1) the carrier redistribution and the novel sandwiched MQWs' high carrier trapping capability; (2) the intrinsic emission property of the MQWs enhanced by improvement of electron‐hole overlap and reduction of quantum confined Stark effect (QCSE) and compositional fluctuation. TDPL under 405 nm laser excitation is also measured to support this view. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Guest–host interaction in an aza crown analog
Authors: Das Ranjita , Chattaraj Pratim Kumar
Published: February 2014

Host–guest interactions in a new aza crown analog
with alkali and alkaline earth metal ions are studied at different levels of theory. All the compounds are optimized at B3LYP/6‐311+G(d) level of theory. To build the general idea about the consequence of methods of computation on the interaction energy of metal ions with the ligand, geometry optimization of some selected planar systems are carried out at the M05‐2X, PBE0, wB97XD, and B3LYP‐D levels. Calculated geometrical parameters, interaction energies, nucleus‐independent chemical shift values, and thermodynamic properties highlight the selectivity associated with these interactions. Further insights into the nature of the bonding in these ion‐macrocyclic supramolecular units are obtained through the natural bond orbital, atoms‐in‐molecules, bond energy decomposition, and electron localization function analyses. © 2014 Wiley Periodicals, Inc.
Scanning electron microscope image signal‐to‐noise ratio monitoring for micro‐nanomanipulation
Authors: Marturi Naresh , Dembélé Sounkalo , Piat Nadine
Published: February 2014

As an imaging system, scanning electron microscope (SEM) performs an important role in autonomous micro‐nanomanipulation applications. When it comes to the sub micrometer range and at high scanning speeds, the images produced by the SEM are noisy and need to be evaluated or corrected beforehand. In this article, the quality of images produced by a tungsten gun SEM has been evaluated by quantifying the level of image signal‐to‐noise ratio (SNR). In order to determine the SNR, an efficient and online monitoring method is developed based on the nonlinear filtering using a single image. Using this method, the quality of images produced by a tungsten gun SEM is monitored at different experimental conditions. The derived results demonstrate the developed method's efficiency in SNR quantification and illustrate the imaging quality evolution in SEM. SCANNING 36:419–429, 2014. © 2014 Wiley Periodicals, Inc.
Confined Iron Fluoride@CMK‐3 Nanocomposite as an Ultrahigh Rate Capability Cathode for Li‐Ion Batteries
Authors: Li Bingjiang , Zhang Naiqing , Sun Kening
Published: February 2014

A facile and advanced architecture design of FeF3·0.33H2O impregnated CMK‐3 nanocomposite (FeF3·0.33H2O@CMK‐3) is presented. In the FeF3·0.33H2O@CMK‐3 nanocomposite, mesoporous carbon CMK‐3 can provide enough passageways for electron and Li+ transport to the confined nanosized FeF3·0.33H2O. The intimate conductive contact between the FeF3·0.33H2O nanoparticles and the carbon framework not only provides an expressway of electron transfer for Li+ insertion/extraction but also suppresses the growth and agglomeration of FeF3·0.33H2O during the crystallization process. As expected, the nanostructured materials exhibit impressive rate capability and excellent cyclicity. Remarkably, even under an ultrahigh charge/discharge rate of 50 C (the charge or discharge process takes a mere 72 s), the confined FeF3·0.33H2O@CMK‐3 still shows a high specific capacity of 78 mAh g−1. By combining confined nanosized active material, high electron conductivity, and open framework, the FeF3·0.33H2O@CMK‐3 nanocomposite demonstrates excellent high‐rate capability and good cycling properties.
Nitrogen‐Doped Graphene/Carbon Nanotube Hybrids: In Situ Formation on Bifunctional Catalysts and Their Superior Electrocatalytic Activity for Oxygen Evolution/Reduction Reaction
Authors: Tian Gui‐Li , Zhao Meng‐Qiang , Yu Dingshan , Kong Xiang‐Yi , Huang Jia‐Qi , Zhang Qiang , Wei Fei
Published: February 2014

There is a growing interest in oxygen electrode catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), as they play a key role in a wide range of renewable energy technologies such as fuel cells, metal‐air batteries, and water splitting. Nevertheless, the development of highly‐active bifunctional catalysts at low cost for both ORR and OER still remains a huge challenge. Herein, we report a new N‐doped graphene/single‐walled carbon nanotube (SWCNT) hybrid (NGSH) material as an efficient noble‐metal‐free bifunctional electrocatalyst for both ORR and OER. NGSHs were fabricated by in situ doping during chemical vapor deposition growth on layered double hydroxide derived bifunctional catalysts. Our one‐step approach not only provides simultaneous growth of graphene and SWCNTs, leading to the formation of three dimensional interconnected network, but also brings the intrinsic dispersion of graphene and carbon nanotubes and the dispersion of N‐containing functional groups within a highly conductive scaffold. Thus, the NGSHs possess a large specific surface area of 812.9 m2 g−1 and high electrical conductivity of 53.8 S cm−1. Despite of relatively low nitrogen content (0.53 at%), the NGSHs demonstrate a high ORR activity, much superior to two constituent components and even comparable to the commercial 20 wt% Pt/C catalysts with much better durability and resistance to crossover effect. The same hybrid material also presents high catalytic activity towards OER, rendering them high‐performance cheap catalysts for both ORR and OER. Our result opens up new avenues for energy conversion technologies based on earth‐abundant, scalable, noble‐metal‐free catalysts.
Graphenal Polymers for Energy Storage
Authors: Li Xianglong , Song Qi , Hao Long , Zhi Linjie
Published: February 2014

A key to improve the electrochemical performance of energy storage systems (e.g., lithium ion batteries and supercapacitors) is to develop advanced electrode materials. In the last few years, although originating from the unique structure and property of graphene, interest has expanded beyond the originally literally defined graphene into versatile integration of numerous intermediate structures lying between graphene and organic polymer, particularly for the development of new electrode materials for energy storage devices. Notably, diverse designations have shaded common characteristics of the molecular configurations of these newly‐emerging materials, severely impeding the design, synthesis, tailoring, functionalization, and control of functional electrode materials in a rational and systematical manner. This concept paper highlights all these intermediate materials, specifically comprising graphene subunits intrinsically interconnected by organic linkers or fractions, following a general concept of graphenal polymers. Combined with recent advances made by our group and others, two representative synthesis approaches (bottom‐up and top‐down) for graphenal polymers are outlined, as well as the structure‐property relationships of these graphenal polymers as energy storage electrode materials are discussed.
Ethical Tax Corporate Governance of State‐owned Enterprises
Authors: Hauptman Lidija , Belak Jernej
Published: February 2014

European Union no longer considers social responsibility (defined as responsibility for one's influences over society) a private affair of companies but requires member states to promote social responsibility and be its role model. Taxes may belong in this model, so do state‐owned enterprises (SOEs). Given the importance of SOEs and recognizing the different practices of (tax) corporate governance, the article focuses on two objectives: firstly, the importance of the impact of the enterprise's key stakeholders in the business ethics planning, and secondly, the role of planning and implementation of tax accounting that will foster enterprises' long‐term development and success based on the enterprise's ethical behavior. The article argues and suggests the ways in which business ethics and tax accounting could helpfully develop Ethical Tax Corporate Governance of SOEs. Copyright © 2014 John Wiley & Sons, Ltd.
Thymol, a monoterpene phenolic derivative of cymene, abrogates mercury‐induced oxidative stress resultant cytotoxicity and genotoxicity in hepatocarcinoma cells
Authors: Shettigar Nishan B. , Das Shubhankar , Rao Nageshwar B. , Rao Satish B. S.
Published: February 2014

Thymol (TOH) was investigated for its ability to protect against mercuric chloride (HgCl2)‐induced cytotoxicity and genotoxicity using human hepatocarcinoma (HepG2) cell line. 3‐(4,5‐Dimethylthiazol‐2‐yl)−2,5‐diphenyl tetrazolium bromide assay confirmed the efficacy of TOH pretreatment in attenuating HgCl2‐induced cytotoxicity. Pretreatment with TOH inhibited HgCl2‐induced genotoxicity, depolarization of mitochondrial membrane, oxidative stress, and mitochondrial superoxide levels. Interestingly, TOH (100 µM) alone elevated the intracellular basal glutathione S‐transferase (GST) levels and TOH pretreatment abrogated the decrease in glutathione, GST, superoxide dismutase, and catalase levels even after HgCl2 intoxication. Furthermore, TOH was also capable of inhibiting HgCl2‐induced apoptotic as well as necrotic cell death analyzed by flowcytometric analysis of cells dual stained with Annexin‐FITC/propidium iodide. The present findings clearly indicate the cytoprotective potential of TOH against HgCl2‐induced toxicity, which may be attributed to its free radical scavenging ability which facilitated in reducing oxidative stress and mitochondrial damage thereby inhibiting cell death. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 968–980, 2015.