bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance stability of AlGaN/GaN HFET: effect of plasma processing
Authors: Baksht Tamara , Knafo Yaron , Yehuda Ilanit , Bunin Gregory 
Published: April 2008

AbstractEffect of fluoride‐based plasma treatment on performance stability of AlGaN/GaN HFET was systematically investigated. The plasma‐based processes can introduce different type of damage that can be permanent or temporary, depending on electrical field in the device, plasma density, and energy of radicals and total process thermal budget. In order to understand more clearly the mechanism of fluorine based plasma treatment on device performance, we compare the effects of Ar, O2 and CF4 based plasma treatments applied before gate definition. Ar plasma was chosen for comparison with CF4 because of high ionization rate of Ar and chemically neutral behavior of Ar ions. Under the same medium range of 40 V DC bias in RIE system for these two gases, the shift of drain current and threshold voltage was similar that indicate the common mechanism of plasma damage. We supposed that the major effect for this phenomenon is a negative electron charge inserted in semiconductor during plasma treatment, because at the same accelerated field the penetration depth for electrons is higher than the penetration depth for fluoride ions. Devices stressed under impact ionization conditions show an improvement of breakdown voltage (for O2 plasma treatment) and some recovery of threshold voltage similar to “walkout effect”. This performance non‐stability raise the serious concern about application of fluorine based technology for power applications, where large voltage/current swing may push device to the impact ionization region. The experimental results show that the implementation of fluoride based plasma treatment for power device manufacturing can affect the performance stability of AlGaN/GaN power HFET. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High power and high gain AlGaN/GaN MIS‐HEMTs with high‐k dielectric layer
Authors: Kanamura M. , Ohki T. , Imanishi K. , Makiyama K. , Okamoto N. , Kikkawa T. , Hara N. , Joshin K. 
Published: April 2008

AbstractHigh power n‐GaN/n‐AlGaN/GaN metal‐insulator‐semi‐conductor high electron mobility transistors (MIS‐HEMTs) with high‐k Ta2O5 dielectric layer were fabricated on a 3‐inch S.I.‐SiC substrate, for the first time. An n‐GaN/n‐AlGaN/GaN MIS‐HEMTs with 400 V breakdown voltage were obtained by using Ta2O5 insulating layer/n‐GaN capstructure. The single‐chip GaN MIS‐HEMTs amplifier with a Ta2O5 layer operated at 50 V achieve a high output power of 113 W with a linear gain of 16.3 dB at 2.5 GHz. We also investigated the RF stress reliability under the P3dB condition. The fluctuation of output power and drain current was lower than 5% even after 150 h stress test. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cervical length and obstetric history predict spontaneous preterm birth: development and validation of a model to provide individualized risk assessment
Authors: Celik E. , To M. , Gajewska K. , Smith G. C. S. , Nicolaides K. H. 
Published: April 2008

AbstractObjectivesTo evaluate the ability of combinations of cervical length and maternal history to assess the risk of spontaneous preterm birth, and to provide a simple procedure for the optimal estimation of risk.MethodsThis prospective observational study was carried out between January 1998 and May 2006. Transvaginal sonographic measurement of cervical length at 20 + 0 to 24 + 6 weeks of gestation was carried out in 58 807 singleton pregnancies as part of routine antenatal care. The outcome measure was spontaneous extreme (< 28 weeks), early (28–30 weeks), moderate (31–33 weeks) and mild (34–36 weeks) preterm birth. Logistic regression analysis was used to derive models for the prediction of spontaneous preterm birth from the maternal obstetric history, demographic characteristics and cervical length.ResultsThe rates of extreme, early, moderate and mild spontaneous preterm birth were 0.23%, 0.24%, 0.57% and 2.93%, respectively. The best prediction of spontaneous preterm birth was provided by cervical length (area under the receiver–operating characteristics curve (AUC), extreme 0.903, early 0.816, moderate 0.784 and mild 0.617) and this was improved by adding obstetric history (AUC, extreme 0.919, early 0.836, moderate 0.819 and mild 0.650). Addition of other parameters was without material effect. For a 10% screen‐positive rate, models using cervical length and obstetric history had a sensitivity of 80.6%, 58.5%, 53.0% and 28.6% for extreme, early, moderate and mild spontaneous preterm birth, respectively. These models were expressed as tables of adjusted likelihood ratios to allow simple estimation of the risk of spontaneous preterm birth.ConclusionsA model combining cervical length and obstetric history provides a better prediction of spontaneous preterm birth than either factor alone, and the sensitivity of screening improves for increasing degrees of prematurity. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Studies on rheology and morphology of POE/PP thermoplastic elastomer dynamically crosslinked by peroxide
Authors: Yuan Bo , Chen Xian , He Bobing 
Published: April 2008

AbstractAn ethylene‐octene copolymer (POE)/polypropylene (PP) thermoplastic elastomer was prepared through dynamically crosslinking by 2,5‐dimethyl‐2,5‐dilbuty (Peroxy) hexane (DHBP). The effects of DHBP concentration, POE/PP ratio, melt flow index (MFI) of PP, and mixer rotation on rheology and morphology of the thermoplastic elastomer were studied. The results showed that with increasing DHBP concentration or POE content, the size of crosslinked particles as well as the melt viscosity increased. Furthermore, agglomerates or a network structure formed as the size of crosslinked particles increased. The melt viscosity also increased as MFI of PP decreased, while the size of crosslinked particles decreased under the same condition. Research on the morphology of dynamically crosslinked POE/PP thermoplastic elastomer flowing through a capillary rheometer at different shear rates show that the reprocessing had little effect on the morphology of dynamically crosslinked elastomer. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.
Influence of third component on mechanical properties and thermal stability of polypropylene/(regenerated polyurethane) blends
Authors: Zhang Shu Ling , Zhang Zhen Xiu , Kim Jin Kuk 
Published: April 2008

AbstractThe possibility of polypropylene (PP) modification by regenerated polyurethane (PU), obtained after partial thermochemical decomposition of waste PU, has been studied. The degradation product was a thermoplastic mixture, applicable for reuse without any purification and fractionation. It was proved that regenerated PU could be reused as an effective polymeric plasticizer for PP and that the addition of regenerated PU did not decrease the thermal stability of PP. In order to improve further the elongation at break of PP modified by regenerated PU, a third component was added to the PP/(regenerated PU) blend. The influence of the third component on the mechanical properties and thermal stability of the blends was evaluated by using a universal testing machine (UTM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The data showed that the elongations of PP/(regenerated PU) blends with styrene‐ethylene‐butylene‐styrene polymer (SEBS) were obviously better than those of the PP/(regenerated PU) blend without the third component and with PP‐g‐MA or SEBS‐g‐MA (MA = maleic anhydride). In addition, the thermal stability of PP/(regenerated PU) blends with a third component was almost same as that of the PP/(regenerated PU) blend without a third component. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.
Myasthenia gravis in a patient affected by glycogen storage disease type Ib: A further manifestation of an increased risk for autoimmune disorders?
Authors: Melis D. , Balivo F. , Della Casa R. , Romano A. , Taurisano R. , Capaldo B. , Riccardi G. , Monsurrò M. R. , Parenti G. , Andria G. 
Published: April 2008

SummaryGlycogen storage disease type Ib (GSD Ib, OMIM 232220) is an inborn disorder of glucose metabolism, caused by mutations in the G6PT gene, encoding a glucose 6‐phosphate transporter (G6PT). GSD Ib is mainly associated with fasting hypoglycaemia and hepatomegaly. Most GSD Ib patients also show neutropenia and neutrophil dysfunction and therefore are at risk of developing severe infections and inflammatory bowel disease (IBD). An increased risk for autoimmune disorders, such as thyroid autoimmunity and Crohn‐like disease, has also been demonstrated, but no systematic study on the prevalence of autoimmune disorders in GSD Ib patients has ever been performed. We describe a 25‐year‐old patient affected by GSD Ib who developed ‘seronegative’ myasthenia gravis (MG), presenting with bilateral eyelid ptosis, diplopia, dysarthria, severe dysphagia, dyspnoea and fatigue. The repetitive stimulation of peripheral nerves test showed signs of exhaustion of neuromuscular transmission, particularly evident in the cranial area. Even in the absence of identifiable anti‐acetylcholine receptor antibodies, seronegative MG is considered an autoimmune disorder and may be related to the disturbed immune function observed in GSD Ib patients.
Fractal Dimensions of Simulated and Real Fat Crystal Networks in 3D Space
Authors: Tang Dongming , Marangoni Alejandro G. 
Published: April 2008

AbstractThe microstructure of fat crystal networks is closely related to rheological properties of fat products, and thus is of particular interest to food scientists. The fractal dimensions of fat crystal networks calculated by microscopy methods such as box‐counting, Db, particle‐counting, Df, and mass fractal dimension, Dm, have been extensively employed to quantify the microstructure of fats. This work revealed the microstructural basis of Db, Df, and Dm in 3D space through both computer simulation and experiments on the high melting fraction of milk fat crystal networks. Similar to our previous simulation study on the fractal dimensions of fat crystal networks in 2D space, Db is sensitive to crystal size, area fraction, and not sensitive to distribution orderliness of crystals, which is the percentage of evenly distributed fat crystals within the simulated fat crystal networks. Df and Dm were not affected by any of the microstructural factors studied in the simulation.
Effect of atorvastatin on plasma levels of asymmetric dimethylarginine in patients with non‐ischaemic heart failure
Authors: Young Joanna M. , Strey Christopher H. , George Peter M. , Florkowski Christopher M. , Sies Christiaan W. , Frampton Christopher M. , Scott Russell S. 
Published: April 2008

AbstractBackground:Elevated plasma levels of asymmetric dimethylarginine (ADMA), an endothelial nitric oxide synthase (eNOS) inhibitor, may contribute to endothelial dysfunction in chronic heart failure (CHF). Since statins upregulate eNOS and ameliorate endothelial dysfunction in non‐ischaemic CHF, we hypothesized that this may be in part through modification of ADMA.Aim:To evaluate the effect of atorvastatin on the relationship between ADMA and endothelial function in non‐ischaemic CHF.Methods:Twenty‐four patients with CHF (ejection fraction <40%, New York Heart Association Functional Classes II and III) were randomised to atorvastatin treatment (40 mg) or placebo once daily for 6 weeks in a double‐blinded, placebo‐controlled crossover study. Plasma ADMA and L‐arginine levels were measured by HPLC. Endothelial function was assessed by flow‐mediated dilatation and invasive forearm plethysmography.Results:Post‐statin therapy, endothelial function was improved (p<0.05) independent of LDL‐cholesterol reductions, but no changes were observed in ADMA levels or the L‐arginine to ADMA ratio. There was a trend for ADMA to inversely correlate with endothelial function at baseline.Conclusions:Short‐term atorvastatin treatment in non‐ischaemic CHF improves endothelial function but has no effect on ADMA or the L‐arginine to ADMA ratio. Our finding suggests that the observed statin‐induced improvements in endothelial function are likely mediated via alternative pathways.
More is not always better: Cost‐effectiveness analysis of combined, single behavioral and single physical rehabilitation programs for chronic low back pain
Authors: Smeets Rob J. , Severens Johan L. , Beelen Saskia , Vlaeyen Johan W. , Knottnerus J. André 
Published: April 2008

ABSTRACTSeveral treatment principles for the reduction of chronic low back pain associated disability have been postulated. To examine whether a combination of a physical training and operant‐behavioral graded activity with problem solving training is cost‐effective compared to either alone one year post‐treatment, a full economic analysis alongside a randomized controlled trial was conducted. In total 172 patients with chronic disabling non‐specific low back pain referred for rehabilitation treatment, were randomized to 10 weeks of aerobic training and muscle strengthening of back extensors (active physical treatment; APT), 10 weeks of gradual assumption of patient relevant activities based on operant‐behavioral principles and problem solving training (graded activity plus problem solving training; GAP), or APT combined with GAP (combination treatment; CT). Total costs, existing of direct health and non‐health costs and indirect costs due to absence of paid work were calculated by using cost diaries and treatment attendance lists. The Roland Disability Questionnaire was used to calculate the cost‐effectiveness to reduce disability and the gain in quality adjusted life year (QALY) by using the EuroQol‐5D. APT, followed by CT showed, although not significant, higher total costs than GAP. Reduction of disability and gain in QALY did not differ significantly between CT and the single treatment modalities. Based on the incremental cost effectiveness ratios (ICERs) and cost‐effectiveness acceptability curves CT is not cost‐effective at all. However, GAP is cost‐effective regarding the reduction of disability and gain in QALY, and to a lesser degree APT is more cost‐effective than CT in reducing disability.
Effect of the form of the sesame-based diet on the absorption of lignans
Authors: Papadakis Emmanouil N. , Lazarou Despina , Grougnet Raphael , Magiatis Prokopios , Skaltsounis Alexios L. , Papadopoulou-Mourkidou Euphemia , Papadopoulos Athanasios I. 
Published: April 2008

The effect of different forms of sesame-based diets on the concentration of plasma lignans was assayed by estimating the levels of certain lignans (sesame lignans and enterolignans) in the plasma of experimental animals. In a series of experiments, male Wistar rats were fed either a raw sesame-enriched diet or a tahini-enriched diet. The plasma concentration of the lignans (sesame lignans and enterolignans) was determined at various time intervals over a 24 h period after a single administration. Enterodiol and enterolactone concentration in the tahini-treated group was significantly higher than in the raw sesame-treated group. In another series of experiments, male Wistar rats were fed, for 15 d, diets enriched in raw dehulled sesame, sesame perisperm, sesame oil, tahini and a polyphenolic extract derived from the seed perisperm. Enterodiol and enterolactone plasma concentration was high in the case of the sesame perisperm in spite of its low concentration in the assessed sesame lignans. Overall, the levels of the sesame lignans and enterolignans present in plasma seem to be influenced not only by the amount of lignan intake but also by other factors such as the form of the sesame-based diet.
UNTANGLING THE MANY ROOTS OF WEST AFRICAN MANGROVE RICE FARMING: RICE TECHNOLOGY IN THE RIO NUNEZ REGION, EARLIEST TIMES TO c. 1800
Authors: FIELDS-BLACK EDDA L. 
Published: April 2008

ABSTRACTThis study focuses on the ancient past of coastal Guinea's Rio Nunez region, a coastal rice-growing region virtually unexplored by studies of West African rice and rice farmers. It argues that coastal cultivators have adapted mangrove rice-farming systems in situ for approximately the past 1,000 years, a historical period pre-dating the European travelers' accounts on which the current literature heavily relies. Rather than diffusing from the interior, these specialized farming systems grew organically out of land-use systems. Using the comparative method of historical linguistics and cultural vocabulary, the study establishes different stages in coastal farmers' experimentation, adaptation and specialization in the coastal environment and approximates historical dates when the different stages occurred. And with botanical and biological studies of mangrove vegetation, the study distinguishes between the softer, spongy roots of white mangroves and hard, twisted roots of red mangroves. The interdisciplinary evidence reveals that knowledge of white mangroves was an early formative stage in cultivators' fabrication of coastal land-use systems. Lastly, from an examination of loanwords, the study discusses the important contributions made by Mande groups, who speak the Susu language in the Rio Nunez region, in intensifying mangrove rice-farming systems indigenous to the coast and extending them from zones of white to those of red mangroves. The interdisciplinary methods and sources enable the study to capture localized experimentation and innovation as continuous processes, thereby breaking with the current literature's emphasis on diffusion from the interior to the coast.
OIL, BRITISH INTERESTS AND THE NIGERIAN CIVIL WAR
Authors: UCHE CHIBUIKE 
Published: April 2008

ABSTRACTUsing newly available evidence, mainly from the Public Records Office (now the National Archive) in London, this article attempts to unravel the true extent of the role that British oil interests played in the decision of the British government to insist on a ‘One Nigeria’ solution in the Nigeria/Biafra conflict. While the official position of the British government was that its main interest in the Nigeria conflict was to prevent the break-up of the country along tribal lines, the true position was more complex. Evidence in this paper suggests that British oil interests played a much more important role in the determination of the British attitude to the war than is usually conceded. Specifically, Britain was interested in protecting the investments of Shell-BP in Nigerian oil. Furthermore, Britain was also at the time desperate to keep Nigerian oil flowing in order to mitigate the impact of its domestic oil shortfalls caused by the Middle East Six Day War. Supporting a ‘One Nigeria’ solution was considered its safest bet in order to achieve the above objectives.
A Satisfaction Enhancement Intervention for Long‐Term Weight Loss
Authors: Jeffery Robert W. , Linde Jennifer A. , Finch Emily A. , Rothman Alexander J. , King Christie M. 
Published: April 2008

AbstractObjective: To compare the effects of two satisfaction enhancement interventions for weight control on behavioral and weight changes among individuals in a 15‐month weight loss program. The primary hypothesis was that long‐term weight loss would be improved by an intervention that enhances perceived satisfaction with achieved outcomes.Research Methods and Procedures: Men and women (331) were randomized to weight control programs comprised of diet and exercise counseling and a cognitive intervention that emphasized either comparing experienced outcomes with expectation of ideal outcomes or comparing experienced outcomes with pretreatment status. The latter was expected to cause greater satisfaction with weight loss progress.Results: The intervention manipulation was not successful in influencing cognitions, satisfaction, or weight change.Discussion: The potential for intervening on satisfaction per se for the purpose of achieving greater or more sustained weight loss remains to be demonstrated.
Ethnic and Sex Variations in Overweight Self‐perception: Relationship to Sedentariness
Authors: Yancey Antronette K. , Simon Paul A. , McCarthy William J. , Lightstone Amy S. , Fielding Jonathan E. 
Published: April 2008

AbstractObjective: With increasing frequency, health promotion messages advocating physical activity are claiming weight loss as a benefit. However, messages promoting physical activity as a weight loss strategy may have limited effectiveness and cross‐cultural relevance. We recently found self‐perceived overweight to be a more robust correlate of sedentary behavior than BMI in Los Angeles County adults. In this study, we examined ethnic and sex differences in overweight self‐perception and their association with sedentariness in this sample.Research Methods and Procedures: We conducted bivariate and multivariate analyses of cross‐sectional survey data from a representative sample of Los Angeles County adults.Results: Women were more likely to perceive themselves to be overweight than men overall (73.2% of overweight/non‐obese and 24.1% of average weight women vs. 44.5% of overweight/non‐obese and 5.6% of average weight men) and within each ethnic group. African‐Americans were least likely (41.3% of overweight/non‐obese African‐Americans self‐identified as overweight) and whites were most likely to consider themselves overweight (60.6% of overweight/non‐obese whites self‐identified as overweight). Overweight (vs. average weight) self‐perception was correlated with sedentariness among average weight adults (45.3% vs. 33.0%, p < 0.001), overweight adults (43.4% vs. 33.6%, p < 0.001), men (average and overweight: 38.4% vs. 27.8%, p < 0.001), overweight whites (41.9% vs. 29.7%, p = 0.0012), and African‐Americans and Latinos (41.6% vs. 33.9%, p = 0.005).Discussion: These data suggest that our society's emphasis on weight loss rather than lifestyle change may inadvertently discourage physical activity adoption/maintenance among non‐obese individuals. However, further research is needed, particularly from prospective cohort and intervention studies, to elucidate the relationship between overweight self‐perception and healthy lifestyle change.
Low Dairy Intake in Early Childhood Predicts Excess Body Fat Gain
Authors: Moore Lynn L. , Bradlee M. Loring , Gao Di , Singer Martha R. 
Published: April 2008

AbstractObjective: To estimate the effect of dairy intake in early childhood on the acquisition of body fat throughout childhood.Research Methods and Procedures: Ninety‐nine of the original 106 families enrolled in the Framingham Children's Study with a child age to 6 years at baseline were followed into adolescence through yearly clinic visits and periodic data collection throughout each year. Dairy intake for these analyses was derived from a mean of 15 days of diet records per subject collected before age 6. A trained examiner took two measurements each year of height, weight, and triceps, subscapular, suprailiac, and abdominal skinfolds using a standardized protocol. Yearly change in body fat was estimated as the slope of these anthropometry measures from ages 5 to 13 years. Early adolescent body fat was estimated as the mean of all available measurements from 10 to 13 years of age.Results: Children in the lowest sex‐specific tertile of dairy intake during preschool (i.e., <1.25 servings per day for girls and <1.70 servings per day for boys) had significantly greater gains in body fat during childhood. These children with low dairy intakes gained more than 3 additional mm of subcutaneous fat per year in the sum of four skinfold measures. By the time of early adolescence, those in the lowest tertile of dairy intake had a BMI that was approximately two units higher and an extra 25 mm of subcutaneous fat.Discussion: Suboptimal dairy intakes during preschool in this cohort were associated with greater gains in body fat throughout childhood.