bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific absorption rates and signal‐to‐noise ratio limitations for MRI in very‐low magnetic fields
Authors: Hayden M. E. , Bidinosti C. P. , Chapple E. M. 
Published: November 2012

AbstractCoil loading experiments were performed to characterize specific absorption rates (SARs) for adult human subjects in uniform linearly‐polarized time‐varying magnetic fields B from 30 kHz to 1.25 MHz, corresponding to a range of Larmor frequencies f that is relevant to MRI in very‐low magnetic fields. For oscillating fields directed perpendicular to the sagittal plane of the human body in the standard anatomical position it was found that
$ {\rm{SAR}} = 4.3(1) \times 10^{ - 7} (M/L)f^2 B^2 $, where M and L are the mass and height of the subject and all quantities are expressed in SI base units. The average linear density M/L appearing in this expression was observed to be an excellent anthropomorphic index for characterizing the manner in which SAR depends on the average transverse dimension of the subject normal to the applied field. As anticipated, SAR values over this frequency range were low compared to those observed at higher frequencies, indicating that emerging applications requiring high duty‐cycle and/or intense radio‐frequency MR tipping pulses will not lead to excessive heating of tissues. Data from these experiments also corroborate and quantify predictions that significant improvements in signal‐to‐noise‐ratios can be achieved through appropriate receive‐antenna design. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 281–294, 2012.
Uncertainty analysis for absorption and first‐derivative electron paramagnetic resonance spectra
Authors: Tseitlin Mark , Eaton Sandra S. , Eaton Gareth R. 
Published: November 2012

AbstractElectron paramagnetic resonance experimental techniques produce absorption or first‐derivative spectra. Uncertainty analysis provides the basis for comparison of spectra obtained by different methods. In this study, it was used to derive analytical equations to relate uncertainties for integrated intensity and line widths obtained from absorption or first‐derivative spectra to the signal‐to‐noise ratio (SNR), with the assumption of white noise. Predicted uncertainties for integrated intensities and line widths are in good agreement with Monte‐Carlo calculations for Lorentzian and Gaussian lineshapes. Conservative low‐pass filtering changes the noise spectrum, which can be modeled in the Monte‐Carlo simulations. When noise is close to white, the analytical equations provide useful estimates of uncertainties. For example, for a Lorentzian line with white noise, the uncertainty in the number of spins obtained from the first‐derivative spectrum is 2.6 times greater than from the absorption spectrum at the same SNR. Uncertainties in line widths obtained from absorption and first‐derivative spectra are similar. The impact of integration or differentiation on SNR and on uncertainties in fitting parameters was analyzed. Although integration of the first‐derivative spectrum improves the apparent smoothness of the spectrum, it also changes the frequency distribution of the noise. If the lineshape of the signal is known, the integrated intensity can be determined more accurately by fitting the first‐derivative spectrum than by first integrating and then fitting the absorption spectrum. Uncertainties in integrated intensities and line widths are less when the parameters are determined from the original data than from spectra that have been either integrated or differentiated. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 295–305, 2012.
The Growth Kinetics of Nickel Aluminide Coatings by the Bi‐velocity Method
Authors: Wierzba Bartek , Danielewski Marek , Tkacz‐Śmiech Katarzyna , Sieniawski Jan 
Published: November 2012

AbstractIn this work we solve the problem of the simultaneous growth and competition of intermediate phases. The crystal lattice as the frame of reference for diffusion is defined, based on the volume continuity equation. It permits the computation of the material velocity in a system in which reactions at several moving interfaces occur. All reactions lead to the lattice shift due to the difference of diffusivities and molar volumes. We simulate the CVD process followed by annealing in a non‐oxidizing atmosphere. The computed kinetics and concentration profiles are compared with experimental results.
Dose–Response Relationship, Acute Toxicity, and Therapeutic Index between the Alkaloid Extract of Mitragyna speciosa and Its Main Active Compound Mitragynine in Mice
Authors: Sabetghadam Azadeh , Navaratnam Visweswaran , Mansor Sharif Mahsufi 
Published: November 2012

Abstract

Preclinical Research

Mitragyna speciosa is a widely used medicinal plant that is commonly used for its morphine‐like effect sin folklore medicine in Thailand and Malaysia due to its ability to reduce pain and ameliorate withdrawal signs after cessation of opioid abuse. The aim of the present study was to determine and compare the relative safety and therapeutic indices of M. speciosa alkaloid extract and its major component, mitragynine. An alkaloid extract (20–400 mg/kg) from the leaves of M. speciosa, as well as mitragynine (4.2–84 mg/kg), was orally administered to mice; dose–response relationship, ED50 and LD50 values, as well as the therapeutic index (TI), for the two substances were determined and compared with that of morphine (2.5–10 mg/kg, s.c.). The results showed a significant dose‐dependent response in both extract (50 mg/kg onward) and mitragynine (10.5 mg/kg) with a higher potency of mitragynine than that of the extract. Although the LD50 for the extract (591 mg/kg) was higher than that of mitragynine (477 mg/kg), the TI for mitragynine was wider than that of the extract (21:3). The present study indicated that mitragynine is relatively safer when compared with the alkaloid extract of M. speciosa in mice.
Assessment of early diabetic renal changes with hyperpolarized [1‐13C]pyruvate
Authors: Laustsen Christoffer , Østergaard Jakob Appel , Lauritzen Mette Hauge , Nørregaard Rikke , Bowen Sean , Søgaard Lise Vejby , Flyvbjerg Allan , Pedersen Michael , Ardenkjær‐Larsen Jan Henrik 
Published: November 2012

AbstractBackgroundThis experimental study explores a novel magnetic resonance imaging/spectroscopic (MRI/MRS) method that measures changes in renal metabolism in a diabetic rat model. This hyperpolarized metabolic MRI/MRS method allows monitoring of metabolic processes in seconds by >10 000‐fold enhancement of the MR signal. The method has shown that the conversion of pyruvate to bicarbonate, i.e. pyruvate dehydrogenase (PDH) activity, is significantly altered in the myocardium already at the onset of diabetes, and the predominant Warburg effect is a valuable cancer maker via the lactate dehydrogenase (LDH) activity. We hypothesize that a similar change in PDH and LDH could be found in the early diabetic kidney.MethodsIn a streptozotocin rat model of type 1 diabetes, hyperpolarized 13C‐MRI and blood oxygenation level‐dependent 1H‐MRI was employed to investigate the changes in renal metabolism in the diabetic and the control kidneys in vivo.ResultsThe diabetic kidney showed a 149% increase in the lactate/pyruvate ratio compared with the control rat kidney, whereas the bicarbonate/pyruvate ratio was unchanged between the diabetic and the control rat kidneys, consistent with literature findings. These metabolic findings paralleled a reduced intrarenal oxygen availability as found by blood oxygenation level‐dependent MRI.DiscussionHyperpolarized 13C‐MRI shows promise in the diagnosis and monitoring of early renal changes associated with diabetes, with the pyruvate/lactate ratio as an imaging biomarker for regional renal changes. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of fortified milk on lyso‐platelet‐activating factor acetyltranferase and lipoprotein‐associated phospholipase A2 in hypercholesterolemic adults
Authors: Ntzouvani Agathi , Nomikos Tzortzis , Petrogianni Maria , Dede Vasiliki , Stamatakis George , Manios Yannis 
Published: November 2012

AbstractHypercholesterolemia is associated with subclinical inflammation, characterised by elevated proinflammatory mediators. Lyso‐platelet‐activating factor acetyltransferase (lyso‐PAF AT) and lipoprotein‐associated phospholipase A2 (Lp‐PLA2) are two key metabolic enzymes of platelet‐activating factor (PAF), a potent inflammatory lipid mediator. Little information is available concerning the efficacy of a dietary intervention on the metabolism of PAF. The objective of the study was to evaluate the effect of fortified milk on the activity of these enzymes. Forty‐three adults (mean age 49.8 ± 8.1 years) with body mass index <35 kg/m2, and total cholesterol >200 but <310 mg/dL were randomised to two groups; (i) intervention group received 500 mL/day (two glasses) of a low‐fat milk fortified with phytosterols, linoleic and alpha linolenic acids, vitamin C, vitamin E, vitamin A, vitamin B6, vitamin B12, folic acid, magnesium and selenium (n = 22), and (ii) placebo group received 500 mL/day of a conventional low‐fat milk (n = 21) for 3 months. Outcome measures were the activities of lyso‐PAF AT from leukocytes and serum Lp‐PLA2 determined with established methods. None of the activities changed significantly during the study in the intervention group, lyso‐PAF AT (95% confidence interval: −1.7, 2.3 nmol/min/mg; p = 0.246), and Lp‐PLA2 (−7.8, 5.8 nmol/min/mL, p = 0.591). No difference was observed between the two groups. In conclusion, daily intake of two glasses of phytosterols, antioxidants, linoleic and linolenic acids via fortified milk for three months had no effect on the activity of either lyso‐PAF AT or Lp‐PLA2.Practical applications: Platelet‐activating factor (PAF) was the first intact phospholipid known to have messenger functions in which the signaling results from the molecule binding to specific receptors on the plasma membrane or other membranes of the cell. It has a number of pro‐inflammatory properties, and affects several critical points of atherogenesis including thrombosis, inflammation, and oxidation. Fortification of milk with nutrients that possess anti‐inflammatory properties and administration to adults with elevated blood cholesterol could provide a means to controlling inflammatory process through the synthesis and degradation of PAF in a population group at risk for cardiovascular morbidity and mortality.
Influence of precursors on the formation of 3‐MCPD and glycidyl esters in a model oil under simulated deodorization conditions
Authors: Freudenstein Anne , Weking Julia , Matthäus Bertrand 
Published: November 2012

AbstractTo find new ways for reducing the potential of palm oil to form 3‐monochloropropane‐1,2‐diol (3‐MCPD) and glycidyl esters during refining it is helpful to know more about the influence of different precursors like diacylglycerols (DAGs) and monoacylglycerols (MAGs), lecithin, and chlorine containing compounds. After adding increasing amounts of the different precursors to a model oil obtained by removal of polar compounds from crude palm oil and heating the mixture under standardized conditions to 240°C for 2 h the contents of 3‐MCPD and glycidyl esters were analyzed according to the standard procedure of DGF C‐VI 18 (10). DAGs and MAGs were found to increase the potential of palm oil to form 3‐MCPD and glycidyl esters, but refined lecithin showed no influence. Sodium chloride as well as tetra‐n‐butylammoniumchloride (TBAC) led to higher contents of the esters. Whereas the addition of TBAC raised the amount of glycidyl esters as well as 3‐MCPD esters, sodium chloride largely raised the amount of 3‐MCPD esters. An addition of 5 mmol of sodium carbonate/kg model oil spiked with sodium chloride reduced the amount of glycidyl esters almost completely; the 3‐MCPD esters were reduced by 50%. About 1 mmol sodium hydrogen carbonate/kg oil reduced both 3‐MCPD and glycidyl esters almost completely.Practical applications: For the mitigation of the formation of 3‐MCPD esters and related compounds in refined edible oils, it is helpful to know more about the effect of different possible precursors. Using a broader data basis, it is possible to adopt the oil processing but especially the choice of the raw material to the demands of the market for lower contents of the esters in the refined products.
Silver‐Catalyzed Cyclization of N‐(Prop‐2‐yn‐1‐yl)pyridin‐2‐amines
Authors: Chioua Mourad , Soriano Elena , Infantes Lourdes , Jimeno M. Luisa , Marco‐Contelles José , Samadi Abdelouahid 
Published: November 2012

AbstractWe report herein the silver‐catalyzed cycloisomerization of readily available N‐(prop‐2‐yn‐1‐yl)pyridine‐2‐amines as a new and practical method for the synthesis of differently substituted 3‐methylimidazo[1,2‐a]pyridines. The isomerization reactions proceeded under mild reactions conditions to give good yields and excellent regioselectivity. A DFT‐based mechanistic analysis is also reported.
Dust emission in northern China: atmospheric emission–dispersion modelling of a major dust event
Authors: Pasqui Massimiliano , Taramelli Andrea , Barbour Jonathan , Kirschbaum Dalia , Bottai Lorenzo , Busillo Caterina , Calastrini Francesca , Gualtieri Giovanni , Guarnieri Francesca , Small Chris 
Published: November 2012

ABSTRACTComprehensive modelling of dust events requires a full physical representation of small‐scale emission mechanisms and description of long‐range transport dynamic. In this paper we propose a simulation system that integrates three different models in order to represent the whole dust cycle. The RAMS atmospheric model configuration has two nested grids, at 50 km and 10 km horizontal resolution, and is used to force both the dust emission model DUSTEM, and the transport model CAMx. The performance of the three‐model simulation system was evaluated using a major dust storm that occurred in March 2002 in the desert of the Alashan Prefecture (Inner Mongolia, China) and which had a significant impact over a large area in northern China. In order to identify potential active dust sources, a specific remote sensed analysis, calibrated through a field campaign in the Alashan Prefecture region, has been assimilated in the modelling system. Simulated dust storm features, from the higher resolution grid, are in good agreement with observed data: surface wind values discrepancies are less than 2 m/s in the Alashan area and less than 5 m/s along the dust storm track. In comparison to ground observations, the modelled dust surface concentration peaks in Beijing differ by only 2 mg/m3 although the timing of dust peaks is delayed in the model. As a consequence this integrated numerical model, along with the remote sensed land surface characterization, is suggested to be a practical and flexible tool for simulating and analysing the whole dust storm dynamics. Copyright © 2013 John Wiley & Sons, Ltd.
Application of Digital Manuals with a Retinal Imaging Display in Manufacturing: Behavioral, Physiological, and Psychological Effects on Workers
Authors: Nakanishi Miwa , Sato Tomohiro 
Published: November 2012

AbstractThis study analyses the behavioral, physiological, and psychological effects of digital manuals presented by a retinal imaging display (RID) on workers in the manufacturing industry. An RID consists of wearable glasses that enable users to view a digital image overlaying the real world. We conducted an experiment in which subjects assembled an object by referring to different types of manuals. The experimental results suggest that an RID enables users to conveniently examine real objects against information in the manual, reduces the information‐processing load while performing tasks, and supports effortless performance of tasks. However, using a monochrome picture manual with an RID increases the information‐processing load. On the other hand, a full‐color RID movie manual generates additional responses in users, such as psychological satisfaction.
Synthesis and Reactions of 2‐[1‐Methyl‐1‐(pyrrolidin‐2‐yl)ethyl]‐1H‐pyrrole and Some Derivatives with Aldehydes: Chiral Structures Combining a Secondary‐Amine Group with an 1H‐Pyrrole Moiety as Excellent H‐Bond Donor
Authors: Pordea Anca , Stoeckli‐Evans Helen , Dalvit Claudio , Neier Reinhard 
Published: November 2012

AbstractThe synthesis of compound 2 and its derivatives 6 and 8 combining a pyrrolidine ring with an 1H‐pyrrole unit is described (Scheme 2). Their attempted usability as organocatalysts was not successful. Reacting these simple pyrrolidine derivatives with cinnamaldehyde led to the tricyclic products 3b, 9b, and 10b first (Scheme 1, Fig. 2). The final, major products were the pyrrolo‐indolizidine tricycles 3a, 9a, and 10a obtained via the iminium ion reacting intramolecularly with the nucleophilic β‐position of the 1H‐pyrrole moiety (cf. Scheme 1).
“Being‐Imitated” Strategy at Home‐Based Intervention for Young Children with Autism
Authors: Sanefuji Wakako , Ohgami Hidehiro 
Published: November 2012

AbstractPrevious studies have consistently shown that simply imitating children with autism will help to promote amount of gaze and to decrease distance to others. However, whether the “being‐imitated” strategy also affects the development of social cognition has not been clarified. We conducted a 2‐month researcher‐guided and home‐based intervention. Mothers were randomly assigned to two groups: One group was coached to engage the child using imitation, and the other was coached simply to respond contingently to bids. Before and after the 2‐month intervention, imitation skills, understanding the intentions of others’ acts, and gaze toward mothers were measured. Two months of being‐imitated enables the children to raise the general amount of their gaze interaction. The imitation skills also were promoted. On the other hand, the development of understanding others’ intentions was not observed, irrespective of condition. The increase of attention to others, which is facilitated by the accumulation of the being‐imitated experiences, can be generalized to the nonimitating person and results in the imitation of others by the child. Alternatively, the developmental linkages between the being‐imitated strategy and understanding of others’ intentions should be an important research task. The present study also indicates that caretakers can play a significant role in the intervention for a child with autism.
Cost-effectiveness of bazedoxifene compared with raloxifene in the treatment of postmenopausal osteoporotic women
Authors: Hiligsmann Mickael , Sedrine Wafa Ben , Reginster Jean-Yves 
Published: November 2012

Abstract
Bazedoxifene is a novel selective estrogen receptor modulator (SERM) for the prevention and treatment of osteoporosis. In addition to the therapeutic value of a new agent, evaluation of the cost-effectiveness compared with relevant alternative treatment(s) is an important consideration to facilitate healthcare decision making. This study evaluated the cost-effectiveness of bazedoxifene compared with raloxifene for the treatment of postmenopausal women with osteoporosis. The cost-effectiveness of treatment for 3 years with bazedoxifene was compared with raloxifene using an updated version of a previously validated Markov microsimulation model. Analyses were conducted from a Belgian healthcare payer perspective and, the base-case population was women (aged 70 years) with bone mineral density T-score ≤ −2.5. The effects of bazedoxifene and raloxifene on fracture risk were derived from the 3-year results of a randomized, double-blind, placebo-controlled and active-controlled study, including postmenopausal women with osteoporosis. The cost-effectiveness analysis based on efficacy data from the overall clinical trial indicated that bazedoxifene and raloxifene were equally cost-effective. When the results were examined based on the subgroup analysis of women at higher risk of fractures, bazedoxifene was dominant (lower cost for higher effectiveness) compared with raloxifene in most of the simulations. Sensitivity analyses confirmed the robustness of the results, which were largely independent of starting age of treatment, fracture risk, cost, and disutility. In addition, when the cost of raloxifene was reduced by one-half or when incorporating the raloxifene effects on reducing breast cancer, bazedoxifene remained cost-effective, at a threshold of €35,000 per quality-adjusted life-years gained, in 85% and 68% of the simulations, respectively. Under the assumption of improved antifracture efficacy of bazedoxifene over raloxifene in women with high risk of fractures, this study suggests that bazedoxifene can be considered cost-effective, and even dominant, when compared with raloxifene in the treatment of postmenopausal osteoporotic women. © 2013 American Society for Bone and Mineral Research.
Acid Denaturation and Refolding of Cytochrome c on Silica Surface
Authors: Campbell Christopher M. J. , Fontana Matthew T. , Taggart Benjamin C. , Su Meng‐Chih , Lin Chung‐Lu , Chang Huan‐Cheng , Chen Hui‐Jung 
Published: November 2012

AbstractDenaturation of oxidized cytochrome c (cyt c) adsorbed to a hydrophilic fused silica surface was studied by UV‐VIS attenuated total reflection (ATR) spectroscopy using a multiple optical pass system newly developed by this lab. Cyt c surface adsorption at neutral pH gave an adsorption equilibrium constant of Ka = 2 × 105 M−1 and a surface coverage at 63% of a monolayer saturation. Protein unfolding by acid denaturation was studied by equilibrating surface bound cyt c with acid buffers ranging in pH from 5 to 2. Protein orientation and surface coverage were calculated based on a theoretical model developed in previous work. The average heme tilt angle (44°) was found to be independent of pH, implicating protein‐surface interactions as the dominant factor governing adsorption. A non‐random molecular orientation distribution of cyt c on the surface was observed, providing further support for the dominance of protein‐surface interactions. It was shown that when denaturing acid buffers were removed and replaced with a neutral buffer cyt c refolded, assuming their original conformation. The combination of unique, yet applicable, science and laboratory skills involved in this project had a tremendous impact on the authors‘ undergraduate curriculum, making it ideal for capstone project development.
Assessment of myelination in hypomyelinating disorders by quantitative MRI
Authors: Dreha‐Kulaczewski Steffi F. , Brockmann Knut , Henneke Marco , Dechent Peter , Wilken Bernd , Gärtner Jutta , Helms G. 
Published: November 2012

AbstractPurpose:To apply myelin‐sensitive quantitative magnetic resonance imaging (MRI) techniques in defined hypomyelinating conditions and to identify spatial patterns of myelination as criteria for characterization of undefined disorders.Materials and Methods:Seven patients were included, based on the diagnosis of mitochondrial cytopathy, Pelizaeus‐Merzbacher disease, GJA12/GJC2‐related Pelizaeus‐Merzbacher‐like disease, hypomyelination with atrophy of the basal ganglia and cerebellum, and leukoencephalopathy with ataxia, delayed dentition, and hypomyelination. The control group comprised 23 children and adolescents (age range 2.6–22.4 years). The 3T MRI protocol consisted of high‐resolution T1‐ and T2‐weighted 3D MRI, diffusion tensor (DTI), and magnetization transfer (MT) imaging. Parameter maps of mean diffusivity, fractional anisotropy, and MT saturation were displayed as pseudocolor overlays and assessed by region‐of‐interest and histogram analysis.Results:Structural MRI revealed widespread signal alterations in white matter, but were hampered by signal heterogeneity. Quantitative DTI and MT reflected the degree of hypomyelination and discriminative patterns of myelination emerged on MT saturation maps.Conclusion:The quantitative parameters in the defined hypomyelination conditions provide additional criteria to further classify undefined white matter disorders. J. Magn. Reson. Imaging 2012; 36:1329–1338. © 2012 Wiley Periodicals, Inc.