bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple method for the separation and quantification of neutral lipid species using GC‐MS
Authors: Borrull Anna , López‐Martínez Gema , Poblet Montse , Cordero‐Otero Ricardo , Rozès Nicolas 
Published: August 2014

A simple gas chromatography‐mass spectrometry (GC‐MS) method has been developed for the determination of neutral lipids in yeast. This method was compared to the conventional thin‐layer chromatography (TLC) method used in our laboratory. The new method enabled the measurement of molecular species of diacylglycerols, triacylglycerols, and sterol esters (SE). With a classic lipid extraction, samples can be injected directly into the GC‐MS without any previous derivatization procedure. However, the main characteristic of this new method is its versatility because GC parameters can be modified based on the biological samples analyzed: volume and injection modes, derivatization of samples, etc. In order to validate the method, yeast lipid extracts from two distinct culture growth conditions were compared, the first in presence of oxygen and the second in its absence. Although the lipid profile of both yeast samples is qualitatively similar, the use of the GC‐MS method rather than the TLC method enables the identification of a sterol, neoergosterol, in yeast cells grown in absence of oxygen. Moreover, this method enables phospholipid detection in samples but their identification is difficult.GC‐MS total ion chromatogram of full chromatogram of yeast lipid extracts (positive values represent cells grown in the presence of oxygen while negative values represent cells grown without oxygen). STs: sterols; PLs: phospholipids; DAGs: diglycerides; SEs: sterol esters; TAGs: triglycerides.
Oil composition in stored walnut cultivars—quality and nutritional value
Authors: Christopoulos Miltiadis V. , Tsantili Eleni 
Published: August 2014

The effects of temperature and O2 availability on quality attributes and nutritional value of oil in four walnut (Juglans regia L.) cultivars (Chandler, Hartley, Franquette, and Ioli) were investigated. Dried kernels, all of initial high quality, were packaged under air or N2 or CO2 and stored at 1 °C or 20 °C for 12 months. Results showed that the saturated fatty acids (SFA) myristic, palmitic, stearic, and arachidic remained stable during storage, whereas the unsaturated palmitoleic, oleic (OL), gondoic, linoleic (LL) and linolenic (LN) decreased, with the stable vaccenic being the exception. Rancidity, assessed as free fatty acids and peroxide value, increased after 12 months, and rancidity evolution found to be correlated with LL and LN, but not with OL. In all cultivars, low temperature and N2 or CO2 prevented additively the fatty acid (FA) losses and rancidity increases. The best results were obtained in walnuts stored at 1 °C under N2 or CO2, while storage at 20 °C under air led to the greatest product deterioration. However, storage at 20 °C under N2 or CO2 and at 1 °C under air showed intermediate results and similar among them. The cultivar affected the kernel oil content and FA profile initially, as well as, the FA decreases and rancidity development during storage. The omega‐6/omega‐3 ratio largely depended on cultivar and was affected by storage conditions. Overall, the storability of the studied cultivars in descending order was Chandler > Hartley, Franquette > Ioli.Practical applications: Storage at 1 °C under N2 or CO2 for 12 months retained the peroxide value (PV) lower than 3 meq O2 kg−1 oil and the free fatty acids (FFA) up to 0.6%, cut‐off values for acceptable walnuts, as suggested by the walnut industry in California. Storage at 20 °C under N2 or CO2 increased the PV value up to 10 meq O2 kg−1 oil, being the upper acceptable limit according to panel tests in studies. For energy savings, the 12‐months storage at 20 °C with low O2 availability can substitute the storage at 1 °C under air. Rancidity development and nutritional value related to fatty acids largely depended on cultivar. Thus, the cultivar factor should also be considered for storage purposes and according to the destination markets.Effects of temperature and packaging atmosphere on rancidity and nutritional value related to oil composition in stored dried kernels of walnut (Juglans regia L.) cultivars. The present results are summarized in the bi‐plot (combination of score and load plots) of Principal Component Analysis. Each color corresponds to each cultivar. Rhombuses, circles, squares, and triangles, corresponding to different storage conditions, indicate the position of each walnut sample in score plot. Daggers indicate the position of major fatty acids and indicators of rancidity in load plot.
Raman spectroscopy study of edible oils and determination of the oxidative stability at frying temperatures
Authors: Carmona María Á. , Lafont Fernando , Jiménez‐Sanchidrián César , Ruiz José R. 
Published: August 2014

Samples of edible oils of different degrees of unsaturation were studied by Raman spectroscopy. We demonstrate the potential of this technique for discriminating these oils. In addition, the Raman spectra for the macadamia, pecan, and Brazil nut oils are for the first time reported here. The fatty acid profile of each type of oil was established by GC. The analytical results obtained from the spectra were highly correlated with those provided by GC as regards the contents in monounsaturated and PUFA of each oil type. Spectra were examined separately in the wavenumber zones 2800–3100 and 800–1800 cm−1, which were those exhibiting the greater differences between oils. Also, as shown in this work, Raman spectroscopy is an effective tool for assessing oxidation in various grades of olive oils. Based on the results, extra virgin olive oil efficiently resists oxidation in the short term by virtue of its increased antioxidant contents.Practical applications: In this paper we show the usefulness of Raman spectroscopy to distinguish between edible oils. Similarly, the technique also allows us to discriminate between different heat‐treated olive oils. At the industrial level Raman spectroscopy can be a useful tool to detect adulteration related to the oxidation of fat. Its ease of use and the absence of sample handling make it very effective for use in production systems on‐line.Raman spectroscopy allows to distinguish oils with different unsaturation level and also allows us to discriminate between different heat‐treated oils.
Platinum‐Decorated Nitrogen‐Doped Graphene Foam Electrocatalysts
Authors: Liu J. , Takeshi D. , Sasaki K. , Lyth S. M. 
Published: August 2014

AbstractLarge‐scale, facile synthesis of nitrogen‐doped graphene foam (GF) from low cost precursors is reported as a support material for platinum in fuel cell cathodes. The nitrogen‐doped GF was produced by combustion of nitrogen‐containing sodium alkoxide, followed by washing and heat treatment in various gases. A nitrogen‐free reference sample was also synthesized. The BET surface area is higher than 700 m2 g−1, and the material is highly defective, partly due to the inclusion of nitrogen, and partly due to the low temperature, catalyst‐free synthesis method. These defects result in an excellent distribution of platinum nanoparticles on the surface. The electrochemical performance of the resulting electrocatalysts was characterized using cyclic voltammetry and linear sweep voltammetry, revealing that nitrogen doping has potential to increase the durability of graphene‐based catalysts. Therefore, this material is a potentially useful catalyst support for use in polymer electrolyte membrane fuel cells.
Effects of Carbonization Temperature and Time during Carbon Riveting Process on the Stability of Pt/C Catalyst
Authors: Jiang Z.‐Z. , Wang Z.‐B. , Rivera H. , Qu W.‐L. , Gu D.‐M. 
Published: August 2014

AbstractEffects of carbonization temperature and time during carbon riveting process on the stability of Pt/C catalysts have been investigated systematically. X‐ray diffraction, transmission electron microscopy, cyclic voltammograms, and accelerated potential cycling tests have been performed to characterize the catalysts. The experimental results show that the activity of the riveted Pt/C catalyst decreases with the increasing of the heat‐treated temperature and the extension of heat‐treated time due to sintering of Pt nanoparticles. The stability of the carbon riveted Pt/C catalysts exhibits the increasing trend with the increase of the carbonization time and temperature. Considering both of the activity and stability of the riveted Pt/C catalysts, the optimized carbonization temperature and time are 400 °C and 60 min for a Pt/VulcanXC‐72 catalyst with starting particle size before carbonization of 2.2 nm and 20 wt% platinum loading, respectively.
MOTHER–CHILD AND FATHER–CHILD INTERACTION WITH THEIR 24‐MONTH‐OLD CHILDREN DURING FEEDING, CONSIDERING PATERNAL INVOLVEMENT AND THE CHILD'S TEMPERAMENT IN A COMMUNITY SAMPLE
Authors: Cerniglia Luca , Cimino Silvia , Ballarotto Giulia 
Published: August 2014

ABSTRACTThe article aims to study mother–child and father–child interactions with 24‐month‐old children during feeding, considering the possible influence of time spent by the parent with the child, the infantile temperament, and the parental psychological profile. The families were recruited from 12 preschools in Italy (N= 77 families). Through an observation of the feeding [Scala di Valutazione dell'Interazione Alimentare (SVIA – Feeding Scale; I. Chatoor et al.,; L. Lucarelli et al.,)], self‐reporting [Symptom Checklist‐90‐Revised (SCL‐90‐R; L.R. Derogatis,), and report‐form questionnaires [Italian Questionnaires on Temperament (QUIT; G. Axia,)], and information provided by the parents about the amount of time spent with their children, results showed that the overall quality of father–child interactions during feeding is lower than that of mother–child interactions. Fathers showed higher psychological symptoms than did mothers. No associations were found between the fathers’ psychopathological risk and the quality of interactions with their children during feeding. Mothers’ psychopathological risks predicted less contingent exchanges interactions with their children during feeding. Children's temperaments significantly influence mother–child interactions, but no association exists between maternal involvement and the quality of interactions with their children. Paternal involvement predicts a better quality of father–infant interactions when associated with a child's higher scores on Social Orientation. The quality of parents’ interactions with their children during feeding are impacted by different issues originating from the parent's psychological profile, the degree of involvement, and from the child's temperament.
Measuring the tribological performance of all the tappets in a production engine using magnetometer sensors and the effect of lubricant rheology
Authors: Mufti Riaz Ahmad , Zahid Rehan , Qureshi Farrukh , Aslam Jawad , Afzal Naqash , Bhutta Muhammad Usman 
Published: August 2014

AbstractTappet rotation is one of the key tribological parameters that play an important role in component wear. Lack of available techniques has discouraged researchers from performing such studies on real production engines. In this research work, a novel experimental technique has been developed that allows the measurement of tappet rotation speed on any engine having direct acting tappets. This unique method does not require any changes or modifications to the components or engine itself. Using this innovative technique, for the first time, all the tappets of a single camshaft have been instrumented, and tappet speed was measured at different operating conditions verifying that not all the tappets behave in the same way. Experimental results clearly showed that all tappets do not respond to the change in lubricant viscosity and the direction of tappet rotation may be one of the factors influencing the performance. Copyright © 2014 John Wiley & Sons, Ltd.
Convergence of FFT‐based homogenization for strongly heterogeneous media
Authors: Schneider Matti 
Published: August 2014

The FFT‐based homogenization method of Moulinec–Suquet has recently attracted attention because of its wide range of applicability and short computational time. In this article, we deduce an optimal a priori error estimate for the homogenization method of Moulinec–Suquet, which can be interpreted as a spectral collocation method. Such methods are well‐known to converge for sufficiently smooth coefficients. We extend this result to rough coefficients. More precisely, we prove convergence of the fields involved for Riemann‐integrable coercive coefficients without the need for an a priori regularization.We show that our L2 estimates are optimal and extend to mildly nonlinear situations and Lp estimates for p in the vicinity of 2. The results carry over to the case of scalar elliptic and curl − curl‐type equations, encountered, for instance, in stationary electromagnetism. Copyright © 2014 John Wiley & Sons, Ltd.
Quantitative susceptibility mapping (QSM) of white matter multiple sclerosis lesions: Interpreting positive susceptibility and the presence of iron
Authors: Wisnieff Cynthia , Ramanan Sriram , Olesik John , Gauthier Susan , Wang Yi , Pitt David 
Published: August 2014

PurposeWithin multiple sclerosis (MS) lesions iron is present in chronically activated microglia. Thus, iron detection with MRI might provide a biomarker for chronic inflammation within lesions. Here, we examine contributions of iron and myelin to magnetic susceptibility of lesions on quantitative susceptibility mapping (QSM).MethodsFixed MS brain tissue was assessed with MRI including gradient echo data, which was processed to generate field (phase), R2* and QSM. Five lesions were sectioned and evaluated by immunohistochemistry for presence of myelin, iron and microglia/macrophages. Two of the lesions had an elemental analysis for iron concentration mapping, and their phospholipid content was estimated from the difference in the iron and QSM data.ResultsThree of the five lesions had substantial iron deposition that was associated with microglia and positive susceptibility values. For the two lesions with elemental analysis, the QSM derived phospholipid content maps were consistent with myelin labeled histology.ConclusionPositive susceptibility values with respect to water indicate the presence of iron in MS lesions, although both demyelination and iron deposition contribute to QSM. Magn Reson Med 74:564–570, 2015. © 2014 Wiley Periodicals, Inc.
Association between right ventricular dysfunction and restrictive lung disease in childhood cancer survivors as measured by quantitative echocardiography
Authors: Patel Amee , Weismann Constance , Weiss Pnina , Russell Kerry , Bazzy‐Asaad Alia , Kadan‐Lottick Nina S. 
Published: August 2014

BackgroundRestrictive lung disease is a complication in childhood cancer survivors who received lung‐toxic chemotherapy and/or thoracic radiation. Left ventricular dysfunction is documented in these survivors, but less is known about right ventricular (RV) function. Quantitative echocardiography may help detect subclinical RV dysfunction. The aim of this study was to assess RV function quantitatively in childhood cancer survivors after lung‐toxic therapy.ProceduresWe identified records of 33 childhood cancer survivors who (1) were treated with lung‐toxic therapy and/or radiation, (2) were cancer‐free for ≥ one year after therapy, and (3) had pulmonary function tests and echocardiograms from their most recent follow‐up visit.ResultsParticipants' mean age was 11.6 ± 4.5 years at cancer diagnosis and 23 ± 8.6 years at evaluation. The most common diagnosis was lymphoma/leukemia (n = 27). Twenty‐nine subjects had anthracycline exposure. Eleven of the 33 subjects demonstrated restrictive pulmonary impairment (total lung capacity 3.69 ± 1.5 L [69.3 ± 22.4% predicted]). Among quantitative measures of RV function, isovolumetric acceleration (IVA), a measure of contractility, was significantly lower in the group with restrictive lung disease (2.42 ± 0.56 vs. 1.83 ± 0.78 m/sec2; P < 0.05). There was a trend towards lower tissue Doppler derived S' and tricuspid annular plane systolic excursion in the group with restrictive lung disease. Subjects with restrictive lung disease were found to have ≥ 2 abnormal parameters (P < 0.01).ConclusionIVA may detect early RV dysfunction in childhood cancer survivors with restrictive lung disease. Our findings require confirmation in a larger study population and validation by cardiac MRI. Pediatr Blood Cancer 2014;61:2059–2064. © 2014 Wiley Periodicals, Inc.
Improved hydroxyurea effect with the use of text messaging in children with sickle cell anemia
Authors: Estepp Jeremie H. , Winter Bryan , Johnson Margery , Smeltzer Matthew P. , Howard Scott C. , Hankins Jane S. 
Published: August 2014

BackgroundIn children with sickle cell anemia (SCA), hydroxyurea reduces morbidity, but adherence is frequently suboptimal. Because most families of children with SCA have access to cellular telephone services, we assessed the impact of text messaged reminders as a tool to improve adherence to hydroxyurea.ProcedureAll patients <19 years of age with HbSS or HbSβ0thalassemia who were treated with hydroxyurea at a maximal tolerated dosage (MTD) at St. Jude Children's Research Hospital Comprehensive Pediatric Sickle Cell Program and who received automated text message reminders (SIMON®) were retrospectively identified. Laboratory parameters, hospitalizations, and medication possession ratios (MPR) prior to and after initiation of SIMON® were compared to assess the impact of SIMON®.ResultsOf the 97.3% of families with access to a cell phone, 91% elected to receive text message reminders. Among 55 children receiving hydroxyurea at MTD, laboratory parameters reflected waning medication compliance during the 12 months prior to SIMON®. Following initiation of SIMON®, children had higher mean corpuscular volumes, hemoglobin levels and fetal hemoglobin percentages and lower absolute reticulocyte counts and bilirubin levels, suggesting improved medication adherence. Hospitalizations were uncommon before and after SIMON®, and medication possession ratios (MPRs) were high before and after SIMON®, neither was significantly changed.ConclusionsSIMON® was feasible and improved hematologic parameters in children with SCA receiving hydroxyurea at a MTD. Future work will include extension of this technology to children with other chronic medical conditions who require daily use of medication. Pediatr Blood Cancer 2014;61:2031–2036. © 2014 Wiley Periodicals, Inc.
High strain‐rate response of spiropyran mechanophores in PMMA
Authors: Hemmer James R. , Smith Patrick D. , van Horn Matt , Alnemrat Sufian , Mason Brian P. , de Alaniz Javier Read , Osswald Sebastian , Hooper Joseph P. 
Published: August 2014

ABSTRACTWe report the high strain‐rate response of a spiropyran (SP) mechanophore in poly(methylmethacrylate). Previous work on this system has demonstrated a reversible bond scission in the SP under local tensile force, converting it to a fluorescent merocyanine form. A Hopkinson bar was used to apply fast compressive loads at rates from 102 to 104 s−1, resulting in significant activation of the SP near fracture surfaces. However, comparison with a similar thermochromic SP reveals that much of the observed activation likely arises from thermal effects during high‐rate fracture. These results show the importance of a thermally active control system in distinguishing mechanochromic response during high‐rate loading. Microscale fluorescence mapping of the fracture surfaces using a confocal Raman microspectrometer suggests that some distinct mechanical activation may be occurring in craze‐like regions during fibril rupture. The thermal response of the SP is useful in its own right for characterizing plastic heating regions during dynamic fracture. Published 2014. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1347–1356
Reactive Species from Cold Atmospheric Plasma: Implications for Cancer Therapy
Authors: Graves David B. 
Published: August 2014

AbstractCold atmospheric plasmas (CAP) formed in air generate reactive oxygen and nitrogen species (RONS). RONS are biologically and therapeutically active agents and experimental evidence suggests that air plasmas shrink tumors by increasing oxidative and nitrosative stress on neoplastic tissue. Most mainline anti‐cancer therapies – including ionizing radiation and chemotherapies – also operate primarily via this pro‐oxidant, oxidative, and nitrosative stress mechanism. The main disadvantage of these conventional therapies is the development of treatment‐resistant cells. A key question for plasma cancer therapies is therefore whether or not cold plasma will lead to similar oxidative stress resistance. However, there are hints that combining nitrosative stress with oxidative stress via air plasma might avoid this problem. Plasma‐based cancer treatment may be a powerful and practical anti‐cancer agent, acting either alone or in combination with other therapies.
Biofilm Responses to Flow Regulation by Dams in Mediterranean Rivers
Authors: Ponsatí L. , Acuña V. , Aristi I. , Arroita M. , García‐Berthou E. , von Schiller D. , Elosegi A. , Sabater S. 
Published: August 2014

AbstractDams regulate downstream hydrology and modify water quality, which in turn can impinge on the biota, especially in rivers naturally subject to large hydrological variability, such as those under Mediterranean climate. The effect of dams on biofilms was analysed in three tributaries (Cinca, Siurana and Montsant) of the Ebro River (NE Spain). We hypothesized that flow regulation would lead to lower spatial variability of biofilms on the streambed and to a decrease in their metabolic rate per unit biomass, especially during low flow periods. Biofilm characteristics were studied in five transects evenly spaced along river reaches upstream (control) and downstream (impact) of dams in each river, along with riverbed granulometry, hydraulics and water chemistry. Chlorophyll‐a, respiratory activity, photosynthetic capacity and efficiency, and extracellular enzymatic activities (β‐d‐glucosidase, alkaline phosphatase and leucine‐amino‐peptidase) of epilithic biofilms were measured in different seasons. Spatial variability of chemical and biological variables was reduced downstream of the dams. Chlorophyll‐a concentration, photosynthetic efficiency and respiration capacity were higher in impact than in control reaches, but generally, low inorganic phosphorus concentrations resulted in comparable phosphatase activities downstream and upstream of dams. On the other hand, β‐d‐glucosidase and leucine‐amino‐peptidase activities were higher at impact reaches. Biofilms were thicker and metabolically more active at the impact reaches, with higher ability to transform dissolved organic matter. Overall, results from this study provide evidence that dams can largely affect the structure and activity of river biofilms, with foreseeable important consequences for river ecosystem functioning. Copyright © 2014 John Wiley & Sons, Ltd.