bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical and magnetic properties of quasi one‐dimensional dilute magnetic ZnMnS and antiferromagnetic MnS
Authors: Chen Limei , Heimbrodt Wolfram , Klar Peter J. , Fröba Michael , Ronning Carsten , von Nidda Hans‐Albrecht Krug
Published: September 2010

We study the optical and magnetic properties of quasi one‐dimensional dilute magnetic Zn1−xMnxS and antiferromagnetic (AF) MnS as a function of size, Mn content x, and sample morphology. On the one hand, we discuss the temporal dynamics of the yellow Mn‐related luminescence of the samples under resonant excitation demonstrating that the non‐exponential behavior of the luminescence decay is an intrinsic feature of such nanostructures and is strongly related to interplay of the characteristic length scales such as the extensions of the sample, the distance between killer centers, and the distance between Mn ions. The transients of the Mn related luminescence can quantitatively be described on the basis of a modified Förster model accounting for killer center statistics and reduced dimensionality. On the other hand, we investigate the paramagnetic to AF phase transition of spherical MnS nanostructures as a function of diameter. The phase transition is gradually suppressed whilst the local magnetic interactions such as the nearest neighbor and next‐nearest neighbor exchange constants remain unaltered, demonstrating that the suppression of the magnetic order is driven by the increasing surface to volume ratio leading to an effective reduction of the numbers of nearest and next‐nearest neighbors.
Mg‐doped Al0.85Ga0.15N layers grown by hot‐wall MOCVD with low resistivity at room temperature
Authors: Kakanakova‐Georgieva A. , Nilsson D. , Stattin M. , Forsberg U. , Haglund Å. , Larsson A. , Janzén E.
Published: September 2010

We report on the hot‐wall MOCVD growth of Mg‐doped Alx Ga1–xN layers with an Al content as high as x ∼ 0.85. After subjecting the layers to post‐growth in‐situ annealing in nitrogen in the growth reactor, a room temperature resistivity of 7 kΩ cm was obtained indicating an enhanced p‐type conductivity compared to published data for Alx Ga1–xN layers with a lower Al content of x ∼ 0.70 and a room temperature resistivity of about 10 kΩ cm. It is believed that the enhanced p‐type conductivity is a result of reduced compensation by native defects through growth conditions enabled by the distinct hot‐wall MOCVD system. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) and UPLC/MSE analysis of RNA oligonucleotides
Authors: Ivleva Vera B. , Yu Ying‐Qing , Gilar Martin
Published: September 2010

Fast and efficient ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) analysis of short interfering RNA oligonucleotides was used for identity confirmation of the target sequence‐related impurities. Multiple truncated oligonucleotides and metabolites were identified based on the accurate mass, and their presumed sequence was confirmed by MS/MS and MSE (alternating low and elevated collision energy scanning modes) methods. Based on the resulting fragmentation of native and chemically modified oligonucleotides, it was found that the MSE technique is as efficient as the traditional MS/MS method, yet MSE is more general, faster, and capable of producing higher signal intensities of fragment ions. Fragmentation patterns of modified oligonucleotides were investigated using RNA 2′‐ribose substitutions, phosphorothioate RNA, and LNA modifications. The developed sequence confirmation method that uses the MSE approach was applied to the analysis of in vitro hydrolyzed RNA oligonucleotide. The target RNA and metabolites, including the structural isomers, were resolved by UPLC, and their identity was confirmed by MSE. Simultaneous RNA truncations from both termini were observed. The UPLC quadrupole time‐of‐flight (QTOF) MS/MS and MSE methods were shown to be an effective tool for the analysis and sequence confirmation of complex oligonucleotide mixtures. Copyright © 2010 John Wiley & Sons, Ltd.
Modelling of Melt Flow and Solidification in the Twin‐Roll Strip Casting Process
Authors: Wang B. , Zhang J.‐Y. , Fan J.‐F. , Zhao S.‐L. , Ren S.‐B. , Chou K.‐C.
Published: September 2010

A three‐dimensional mathematical model has been developed to simulate turbulent fluid flow, heat transfer and solidification in the pool of a twin‐roll strip caster. A Darcy‐porosity approach was used to study the fluid flow within the mushy solidification zone in the pool. The effect of the heat transfer coefficient and permeability constant on the flow and solidification was also predicted. It was shown that an even flow and temperature distribution of the pool can be obtained by using a suitable feeding system. The heat transfer between the rolls and the solidifying metal has a big influence on the location of the solidification end point. The permeability of the mushy zone is a key factor which affects the flow and solidification in the twin‐roll strip casting process.
Modeling Study of Turbulent Flow Effect on Inclusion Removal in a Tundish with Swirling Ladle Shroud
Authors: Solorio‐Diaz G. , Ramos‐Banderas A. , de J. Barreto J. , Morales R. D.
Published: September 2010

The present study is focused on the assessment of a new concept of ladle shroud capable to control the turbulence promoted by the steel entry jet in a continuous casting tundish; the new proposal is a Swirling Ladle Shroud (SLS). It presumed that the SLS decreases the impact velocities in the tundish bottom close to 1/3 of that provided by a conventional shroud. In this mathematical study an analysis of turbulence control and particle removal is made by comparing the SLS with two different conventional tundish arrangements. Particle sizes included 1, 5, 20, 40, 60, 80, 100, 120, 140 and 160 microns. Simulations also included the effects of the mass flow rate on the removal efficiency of non‐metallic inclusions, considering 3.8 and 7.6 ton/min mass flow rates. It was found that the SLS is capable to handle different mass flow rates, opposite to the conventional arrangements where at any increase of mass flow rate, these devices become inefficient to control turbulence, reducing considerably the inclusion removal efficiency. These results illustrate that using a SLS, the turbulent flow control and the particle removal may be better with this new proposal.
Retrogradation of waxy cornstarch studied by DSC
Authors: Liu Hongsheng , Yu Long , Tong Zhen , Chen Ling
Published: September 2010

The retrogradation process of the biphasic endotherms Gr and M1r for waxy cornstarch was systematically investigated using differential scanning calorimetry (DSC). The high temperature endotherm M1r developed significantly within 2–5 h, while the retrograded endotherm Gr appeared after 5 h storage and increased with time. The single endotherm Gr was separated using an analytical software, and the enthalpy was found to be ∼36% of the total enthalpy of the retrograded starch. Compared to normal cornstarch (∼77% amylopectin content), the final retrogradation ratio of the waxy cornstarch was higher. Both the waxy and normal cornstarches investigated showed a similar pattern of retrogradation process, which developed quickly in the initial stage (up to 1 day) and then gradually came to a near‐constant value in the second stage (from 1 to 20 days).
Accuracy of fetal gender determination in the first trimester using three‐dimensional ultrasound
Authors: Youssef A. , Arcangeli T. , Radico D. , Contro E. , Guasina F. , Bellussi F. , Maroni E. , Morselli‐Labate A. M. , Farina A. , Pilu G. , Pelusi G. , Ghi T.
Published: September 2010

Objectives

To evaluate the accuracy of three‐dimensional (3D) ultrasound in fetal gender assignment in the first trimester.

Methods

A series of pregnant women attending at 11 to 13 + 6 weeks for the nuchal translucency (NT) scan were enrolled into the study. An ultrasound volume of each fetus was obtained and stored for offline analysis. On the reconstructed mid‐sagittal plane, the angle between the genital tubercle and an imaginary line passing tangentially through the fetal back (genital angle) was estimated and a receiver–operating characteristics (ROC) curve was constructed to determine the best cut‐off for genital angle in fetal male gender determination. Fetal gender was subsequently ascertained in all cases. To calculate the interobserver variability, a second operator repeated the measurements.

Results

There were 85 cases included in the study. The genital angle in males was significantly higher than that in females (51.2 ± 11.3° (n = 36) vs. 18.9 ± 4.1 (n = 49), P < 0.001). The ROC curve revealed the estimated genital angle to have a high degree of accuracy in fetal gender determination (area under the curve ± SE = 1.000 ± 0.001). The best cut‐off for male gender determination was found to be between 27° and 29° (sensitivity, 100%; specificity, 98.0%). There was a high degree of correlation between the two operators (r2 = 0.998; coefficient of variation = 5.4%).

Conclusions

3D ultrasound is a highly accurate and reproducible tool for fetal gender assignment prior to 14 weeks of gestation. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
State of the art: an integrated approach to pelvic floor ultrasonography
Authors: Santoro G. A. , Wieczorek A. P. , Dietz H. P. , Mellgren A. , Sultan A. H. , Shobeiri S. A. , Stankiewicz A. , Bartram C.
Published: September 2010

Surgical management of pelvic floor disorders depends on a comprehensive understanding of the structural integrity and function of the pelvic floor. For visualizing this region, ultrasonography has emerged as a procedure that is relatively easy to perform, cost‐effective and widely available. In this review, pelvic floor ultrasonography, including two‐dimensional (2D), three‐dimensional (3D) and 4D imaging as well as transvaginal, endoanal and transperineal techniques, is discussed from a global and multicompartmental perspective, rather than using a compartmentalized approach. The role of the different sonographic modalities in the major disorders of the pelvic floor—urinary and fecal incontinence, pelvic organ prolapse and obstructed defecation syndrome—is evaluated critically. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Point prevalence of major depression in Estonia. Results from the 2006 Estonian Health Survey
Authors: Kleinberg A. , Aluoja A. , Vasar V.
Published: September 2010

Aim

The study focuses on the point prevalence of major depressive episode in the Estonian population in 2006 and assesses the relationship of sociodemographic factors, health status indicators, alcohol use, and previous depressive episodes to major depression.

Methods

The present major depressive episode was assessed within the nationally representative, cross-sectional 2006 Estonian Health Survey (EHIS 2006), in which non-institutionalized individuals aged 18–84 years (n = 6105) were interviewed using the Mini-International Neuropsychiatric Interview (MINI).

Results

The point prevalence of major depressive episode in the Estonian population was 5.6%. Depression was higher among females, in the non-Estonian ethnic group, among people older than 40 years, and in the lower-income group.

Conclusions

The point prevalence of major depressive episodes was comparable with the results of other population surveys, being a little higher than the average. Age, income, ethnicity, health status, self-rated health, and previous depressive episode were independent associates of depression.
Heart rate measured in the acute aftermath of trauma can predict post-traumatic stress disorder: A prospective study in motor vehicle accident survivors
Authors: Coronas R. , Gallardo O. , Moreno M.J. , Suárez D. , García-Parés G. , Menchón J.M.
Published: September 2010

Objective

To determine whether increased physiological arousal immediately after trauma or at emergency admission can predict post-traumatic stress disorder (PTSD) in motor vehicle accident (MVA) survivors with physical injuries.

Methods

We included 119 MVA survivors with physical injuries. In this prospective cohort study, heart rate (HR) and blood pressure (BP) were assessed during ambulance transport (T1) and at hospital admission (T2). One and four months after the accident, we assessed patients for PTSD (Davidson trauma scale, confirmed with the structured clinical interview for DSM-IV axis I disorders). Multivariate logistic regression models assessed the relationship between HR or BP and PTSD.

Results

PTSD was diagnosed in 54 (45.4%) patients at 1 month and in 39 (32.8%) at 4 months. In the multivariate analysis, HR at T1 or at T2 predicted PTSD at 1 month (OR=1.156, 95% CI [1.094;1.221] p < 0.0001). Only HR at T1 (not at T2) predicted PTSD at 4 months (OR=1.059, 95% CI [1.013; 1.108] p = 0.012). Injury severity predicted PTSD at 4 months (OR=1.207, 95% CI [1.085; 1.342] p = 0.001). A cut-off of 84 beats per minute yielded a sensitivity of 62.5% and a specificity of 75.0% for PTSD.

Conclusions

HR measured at the scene of MVA and severity of injury predicted PTSD 4 months later.
Clinical significance of obstructive defecatory symptoms in women with pelvic organ prolapse
Authors: Saks Emily K. , Harvie Heidi S. , Asfaw Tirsit S. , Arya Lily A.
Published: September 2010

Objective

To determine whether the presence of obstructive defecatory symptoms is associated with the site and severity of pelvic organ prolapse. Methods: A cross‐sectional study was performed of women with pelvic organ prolapse of grade 2 or greater who had completed a validated questionnaire that surveyed pelvic floor symptoms. Associations between patient characteristics, site and severity of prolapse, and obstructive bowel symptoms were investigated.

Results

Among 260 women with pelvic organ prolapse, women with posterior vaginal wall prolapse were more likely to report obstructive symptoms, such as incomplete emptying (41% vs 21%, P = 0.003), straining at defecation (39% vs 19%, P = 0.002), and splinting with defecation (36% vs 14%, P < 0.001) compared with women without posterior vaginal wall prolapse. There was no significant association between any bowel symptom and increasing severity of prolapse.

Conclusions

Obstructive bowel symptoms are significantly associated with the presence of posterior vaginal wall prolapse, but not with the severity of prolapse.
Prenatal anxiety associated with male child preference among expectant mothers at 10–20 weeks of pregnancy in Xiangyun County, China
Authors: Loo Kek Khee , Li Yan , Tan Ying , Luo Xiying , Presson Angela , Shih Wendy
Published: September 2010

Objective

To examine the relationship between male child preference and maternal prenatal psychological distress among expectant mothers from Xiangyun County, Yunnan Province, China.

Methods

Child gender preference, state‐trait anxiety and depression, relationships with the husband and mother‐in‐law, and self‐esteem were measured in a sample of 198 women between 10 and 20 weeks of pregnancy. Multivariate logistic regression analysis was used to identify risk factors for prenatal anxiety.

Results

Prenatal anxiety was correlated with male child preference (r = 0.15, P < 0.05), maternal age (r = –0.17, P < 0.05), level of education (r = –0.23, P < 0.01), self‐esteem (r = –0.36, P < 0.01), relationship with mother‐in‐law (r = –0.34, P < 0.01), and relationship with husband (r = –0.35, P < 0.01). Significant relationships were maintained in multivariate analysis that included gender preference, maternal education, pregnancy anxiety, self‐esteem, number of people in the household, and relationship with husband as predictors (adjusted r2 = 0.28, P < 0.001).

Conclusion

Male child preference was associated with prenatal anxiety in this sample. Younger maternal age, lower self‐esteem, lower level of education, worse relationship with husband, and less family cohesiveness were also related to prenatal anxiety. Expectant mothers experienced prenatal anxiety when there was strong family preference for sons.
Richard Greenham and the Calvinist Construction of God
Authors: DIXON LEIF
Published: September 2010

Richard Greenham has traditionally been depicted as a ‘comfortable’ or ‘affectionate’ divine, and in recent years it has even been suggested that he was not predestinarian in his theology at all. This article seeks to show that not only was he indeed predestinarian in his theology of salvation, but that the concept of an all-powerful, all-determining deity was central to his pastoral method. Greenham is used as an example in demonstrating that English Calvinism could be pastorally adaptive and successful, not by softening its core ideas, but by strongly emphasising man's inability to earn his own salvation and God's power over both heaven and hell.
Discerning the Spirit: ambivalent assurance in the soteriology of Jonathan Edwards and Barthian correctives
Authors: Hastings W. Ross
Published: September 2010

Assurance of salvation is a matter of perennial pastoral concern and theological controversy. After the Great Awakening, Jonathan Edwards developed a doctrine of assurance based largely on discerning the work of the Spirit in the affections and actions of the professed believer. One might have expected from this theocentric, trinitarian and surprisingly participational theologian a robust doctrine of assurance and a joyful, other-centred spirituality. Ironically, however, profound ambiguities persisted within it which will be shown to arise from the predominantly pneumatic nature of his version oftheosis, a blurring of the distinction between justification and sanctification, and the power of his predominantly psychological analogy of the Trinity. This article will therefore first present the main features of Jonathan Edwards’ doctrine of the assurance of salvation. The second section will evaluate it by outlining factors in Edwards’ theology which might have been expected to produce a high level of certainty concerning assurance, and then those which might militate against this certainty. Whilst Edwards did at times espouse the social analogy of the Trinity, histheosisis constructed predominantly within the psychological analogy. Innovatively modified though it was, because Edwards works within this framework, he overemphasises the pneumatological union of the saints with God, at the expense of the incarnational union of God with and for humanity in Christ. This results correspondingly in an inordinate reliance for assurance on the Spirit's work within the realm of human subjectivity, over against objective christological realities. In short, Edwards’ theology of assurance is, in the end, individualistic and anthropocentric.
The influence of dietary protein and energy intake on the performance, body composition and energy utilization of pigs growing from 7 to 19 kg
Authors: Campbell R. G. , Dunkin A. C.
Published: September 2010

Thirty-six entire male pigs were used to investigate the effects of two levels of dietary crude protein (150 and 220 g/kg) each in combination with four levels of feeding (1·0, 1·32, 1·64 MJ digestible energy/kg M0·73per day andad libitum) on growth, body composition and energy utilization over the live-weight range 7 to 19 kg.

Growth rate responded linearly (P< 0·001) to increasing energy intake but was depressed (P< 0·05) when dietary crude protein was reduced from 220 to 150 g/kg.

Raising digestible energy intake increased and decreased respectively the proportions of fat and protein in the empty body at 19 kg live weight. However, the magnitude of the response of both components to change in digestible energy intake was reduced in the case of pigs fed the lower protein diet.

Total energy retained and that retained as fat and as protein responded linearly (P< 0·001) to change in digestible energy intake of either diet. Extrapolation of the regression of total energy retained on digestible energy intake yielded a digestible energy requirement for maintenance of 510 kJ/kg M0·75per day, which was unaffected by level of dietary protein.

The partial efficiencies of protein utilization, estimated from the regressions of protein deposition (g/day) on protein intake (g/day), were 0·616 and 0·411 for pigs given the diets containing 150 and 220 g crude protein per kg respectively.
A note on in vivo comparison of a urea-formaldehyde-molasses complex and urea molasses mixes as sole nitrogen supplements to a wheat chaff ration for steers
Authors: Lall D. , Makkar H. P. S. , Negi S. S.
Published: September 2010

A urfia-formaldehyde-molasses complex appeared to be a promising slow ammonia-releasing urea derivative in in vitro studies. It was compared with urea-molasses mixtures as a non-protein nitrogen supplement to an ad libitum wheat chaff ration for steers. The significantly lower (P < 0·01) crude protein digestibility and intake of digestible crude protein, and the non-significantly lower nitrogen retention on the urea-formaldehyde-molasses complex ration revealed the superiority of simple urea-molasses mixtures as a non-protein nitrogen supplement.
A Review of the Evidence of Third Sector Performance and Its Relevance for a Universal Comprehensive Health System
Authors: Heins Elke , Price David , Pollock Allyson M. , Miller Emma , Mohan John , Shaoul Jean
Published: September 2010

UK policy promotes third sector organisations as providers of NHS funded health and social care. We examine the evidence for this policy through a systematic literature review. Our results highlight several problems of studies comparing non-profits with other provider forms, questioning their usefulness for drawing lessons outside the place of study. Most studies deem contextual factors and the regulatory framework in which providers operate as much more important than ownership form. We conclude that the literature does not support the policy of a larger role for the third sector in healthcare, let alone a switch to a market-based system.
Das kommt ganz drauf an ...
Authors: Schulze Beate , Janeiro Maya , Kiss Helena
Published: September 2010

Hintergrund: Die psychiatrische Stigmaforschung hat sich bislang auf spezifische Patientengruppen konzentriert, während andere weitgehend ausgeblendet blieben. Diese Arbeit untersucht die persönlichen Stigma-Coping-Strategien von Menschen mit Schizophrenie (n = 31) und Borderline-Persönlichkeitsstörung (n = 50) im Hinblick auf ihre störungsspezifischen Stigma-Erfahrungen. Methode: Im Rahmen einer Mixed-Method-Studie wurden psychisch erkrankte Menschen (n = 100) verschiedener Diagnosegruppen befragt. Stigma-Erfahrungen und Coping-Strategien wurden mittels der deutschen Version des Inventory of Stigmatising Experiences (ISE; Schulze et al., 2009 ; Stuart et al., 2005 ) im Rahmen persönlicher Interviews erhoben. Ergebnisse: Menschen mit Borderline-Syndrom sehen sich häufiger (67 %) mit Stigma konfrontiert als schizophren erkrankte Menschen (54 %). Borderline-Patienten erlebten Stigma häufig im Zusammenhang mit sichtbaren Zeichen ihrer Erkrankungen und litten darunter, über ihre Krankheit definiert zu werden. Für Schizophren Erkrankte hingegen bestand der schlimmste Aspekt ihrer Stigmaerfahrung darin, dass ihre Symptome bzw. ihr Leid von anderen oft nicht ernst genommen werden. Im Umgang mit Stigma nutzen beide Gruppen Geheimhaltung, selektive Vermeidung und Aufklärung. Zusätzlich zu diesen von der Stigma-Forschung vornehmlich untersuchten Strategien setzen die Befragten situationsabhängig ein breites Repertoire an persönlichen Coping-Strategien ein, was dem Bild vom passiven «Stigma-Empfänger» klar widerspricht. Diskussion: Die Ergebnisse verweisen auf die Rolle sichtbarer Krankheitsanzeichen für das Risiko, stigmatisierenden Umweltreaktionen ausgesetzt zu sein. Menschen mit Borderline-Persönlichkeitsstörung scheinen, im Sinne Goffmans, zu den «Diskreditierten» zu gehören, da ihnen wichtige Coping-Strategien wie Geheimhaltung oder selektive Vermeidung nur eingeschränkt zur Verfügung stehen. Effektive Programme zum Stigma-Management müssen auf die bestehenden Coping-Ressourcen der Patienten aufbauen sowie die positiven wie negativen Konsequenzen eines offenen Umgangs mit der eigenen Diagnose realistisch diskutieren.
Source, attenuation, and site parameters of the 1997 Umbria‐Marche seismic sequence from the inversion of P wave spectra: A comparison between constant QP and frequency‐dependent QP models
Authors: de Lorenzo Salvatore , Zollo Aldo , Zito Giammaria
Published: September 2010

The attenuation of P waves, the site responses, and the source parameters (seismic moment, corner frequency, source dimension) of 490 seismic events that occurred during the 1997 Colfiorito, Umbria‐Marche seismic sequence have been inferred from the inversion of P wave velocity spectra. The Boatwright source model has been assumed to model the source spectra. A global nonlinear inversion scheme was developed to avoid any a priori selection of the initial QP and the corner frequency. To establish if a frequency‐dependent QP model fits the data better than a constant QP model, two inversion results have been compared. Application of the Akaike information criterion indicates that the constant QP model represents the best compromise between model simplicity and data misfit. The station QP values are small: in the range of 50 to 200. A one‐dimensional QP model is obtained by back projecting the inverted t*. Our results indicate both well‐defined near‐site attenuation effects at some sites and heterogeneity in the inelastic properties of the crust. With the exception of the amplification response at five seismic stations, most of the recording sites did not show amplification peaks at particular frequencies. The stress drop clearly increases as a function of the seismic moment, which indicates a deviation from self‐similarity, whereas it does not show an increase with depth, probably owing to the effects of fluid pressurization in the crust. A stress drop of about 39 MPa is inferred. The relationship between the seismic moment and the local magnitude for P waves has been calibrated.
Regulation of the tumour suppressor Fbw7α by PKC-dependent phosphorylation and cancer-associated mutations
Authors: Durgan Joanne , Parker Peter J.
Published: September 2010

Fbw7 (F-box WD40 protein 7) is a major tumour suppressor, which mediates the degradation of several potent oncogenes. PKC (protein kinase C) comprises a serine/threonine kinase family that can promote transformation when dysregulated. In the present study, we investigated the relationship between Fbw7 and PKC. Multiple members of the PKC superfamily interact with the substrate-binding domain of Fbw7. However, we find no evidence for Fbw7-mediated degradation of PKC. Instead, we demonstrate that Fbw7 is a novel substrate for PKC. Two residues within the isoform-specific N-terminus of Fbw7α are phosphorylated in a PKC-dependent manner, both in vitro and in mammalian cells (Ser10 and Ser18). Mutational analyses reveal that phosphorylation of Fbw7α at Ser10 can regulate its nuclear localization. Cancer-associated mutations in nearby residues (K11R and the addition of a proline residue at position 16) influence Fbw7α localization in a comparable manner, suggesting that mislocalization of this protein may be of pathological significance. Together these results provide evidence for both physical and functional interactions between the PKC and Fbw7 families, and yield insights into the isoform-specific regulation of Fbw7α.
Gender differences in vascular function and insulin sensitivity in young adults
Authors: Dengel Donald R. , Jacobs David R. , Steinberger Julia , Moran Antoinette M. , Sinaiko Alan R.
Published: September 2010

To examine influence of insulin resistance and other clinical risk factors for the MetS (metabolic syndrome) on vascular structure and function in young adults. This cross-sectional study was conducted in a cohort of young adults (mean age 22 years) and their siblings participating in a longitudinal study of cardiovascular risk (n=370). Insulin sensitivity was determined by euglycaemic insulin clamp. EDD (endothelium-dependent dilation) was determined by flow-mediated dilation using high-resolution ultrasound imaging of the brachial artery. EID (endothelium-independent dilation) was determined by NTG (nitroglycerine)-mediated dilation. The diameter and cIMT (intima–media thickness) of the carotid artery were also measured. There was no significant difference between males and females for age or body mass index. However, males had significantly higher glucose and triacylglycerol (triglyceride) levels, while the females had significantly higher HDL-C (high-density lipoprotein-cholesterol) and insulin sensitivity (13.00±0.33 compared with 10.71±0.31 mg·kg−1 of lean body mass·min−1, P<0.0001). Although peak EDD was significantly lower (6.28±0.26 compared with 8.50±0.28%, P<0.0001) in males than females, this difference was largely explained by adjustment for brachial artery diameter (P=0.15). Peak EID also was significantly lower in males than females (20.26±0.44 compared with 28.64±0.47%, P<0.0001), a difference that remained significantly lower after adjustment for brachial artery diameter. Males had a significantly greater cIMT compared with females (females 0.420±0.004 compared with males 0.444±0.004 mm, P=0.01), but when adjusted for carotid diameter, there was no significant difference (P=0.163). Although there were gender differences in vascular function and structure in the young adult population examined in this study, many of the differences were eliminated simply by adjusting for artery diameter. However, the lower EID observed in males could not be explained by artery diameter. Future studies need to continue to examine influence of gender on EID and other measures of vascular function.
SU(N) irreducible Schwinger bosons
Authors: Mathur Manu , Raychowdhury Indrakshi , Anishetty Ramesh
Published: September 2010

We construct SU(N) irreducible Schwinger bosons satisfying certain U(N-1) constraints which implement the symmetries of SU(N) Young tableaues. As a result all SU(N) irreducible representations are simple monomials of (N−1) types of SU(N) irreducible Schwinger bosons. Further, we show that these representations are free of multiplicity problems. Thus, all SU(N) representations are made as simple as SU(2).
The nonlinear coupling between gyroradius scale turbulence and mesoscale magnetic islands in fusion plasmas
Authors: Hornsby W. A. , Peeters A. G. , Snodin A. P. , Casson F. J. , Camenen Y. , Szepesi G. , Siccinio M. , Poli E.
Published: September 2010

The interaction between small scale turbulence (of the order of the ion Larmor radius) and mesoscale magnetic islands is investigated within the gyrokinetic framework. Turbulence, driven by background temperature and density gradients, over nonlinear mode coupling, pumps energy into long wavelength modes, and can result in an electrostatic vortex mode that coincides with the magnetic island. The strength of the vortex is strongly enhanced by the modified plasma flow response connected with the change in topology, and the transport it generates can compete with the parallel motion along the perturbed magnetic field. Despite the stabilizing effect of sheared plasma flows in and around the island, the net effect of the island is a degradation of the confinement. When density and temperature gradients inside the island are below the threshold for turbulence generation, turbulent fluctuations still persist through turbulence convection and spreading. The latter mechanisms then generate a finite transport flux and, consequently, a finite pressure gradient in the island. A finite radial temperature gradient inside the island is also shown to persist due to the trapped particles, which do not move along the field around the island. In the low collisionality regime, the finite gradient in the trapped population leads to the generation of a bootstrap current, which reduces the neoclassical drive.
Correlation of mass fractal dimension and cluster size of silica in styrene butadiene rubber composites
Authors: Schneider Gerald Johannes , Vollnhals V. , Brandt K. , Roth S. V. , Göritz D.
Published: September 2010

The morphology of the precipitated silica VN3 filled in styrene butadiene rubber was studied as a function of the volume fraction Φ by means of small-angle X-ray scattering experiments. The wide q-range of 0.008 nm−1<q<1 nm−1 probes the structures of the primary particles, the clusters, and resolves a part of the larger clusters of the silica. The diameter of the primary particles and their surface roughness are independent from the silica concentration. The size of the clusters and the corresponding aggregation number depend on Φ. This observation could be ascribed to external mechanical forces because of the mixing process and to growing cluster-cluster interactions with increasing filler fraction. In contrast the mass fractal dimension does not depend on Φ, and by that means experimentally proving that there is not necessarily a correlation between the mass fractal dimension and the cluster size.
Calculation of ground state rotational populations for kinetic gas homonuclear diatomic molecules including electron-impact excitation and wall collisions
Authors: Farley David R.
Published: September 2010

A model has been developed to calculate the ground state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with nonequilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N≥3, with a rotational temperature between the wall and feed gas temperatures. The N=0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.
Polarization of molecular targets using infrared stimulated Raman adiabatic passage
Authors: Mukherjee Nandini , Zare Richard N.
Published: September 2010

We suggest that infrared stimulated Raman adiabatic passage, a coherent multiple excitation process, can be used to create a superposition of (2J+1) highly correlated M-state sublevels of a rigid rotor molecule with vibrational level v and rotational level J. This method employs the (v=0,J−2) to (v=2,J) S-branch transition, which is carried out in a counterintuitive manner in which the v=1 to v=2 transition is pumped prior to the v=0 to v=1 transition, causing nearly complete population transfer to the v=2 final level. We use perpendicular and parallel linearly polarized infrared excitation (biaxial excitation). Specifically, the perpendicular polarization connects the v=1 intermediate level to the final vibrational level v=2, and the parallel polarization connects the initial level v=0 to the intermediate level v=1. By this means we break the cylindrical symmetry for an ensemble of vibrationally excited molecules in a rovibrational eigenstate (v=2,J). The angular momentum polarization is determined by the relative phases rather than by the populations of the magnetic M-sublevels. For the phase correlated ensemble, the angular momentum polarization can be considered as a purely quantum mechanical effect. Using a fully general density matrix treatment, we illustrate this approach by considering a beam of carbon monoxide (CO) molecules. We find that significant polarization for J=2, 5, and 10 can be achieved with a cw infrared laser source having modest power (∼100 mW/mm2). We believe that this technique is a general one and may offer an experimentally accessible new platform for different applications, from scattering studies with M-state entangled ensembles of molecules to logic gate operations of a quantum computer.
Thermal conductivity measurement of individual CdS nanowires using microphotoluminescence spectroscopy
Authors: Liu X. F. , Wang R. , Jiang Y. P. , Zhang Q. , Shan X. Y. , Qiu X. H.
Published: September 2010

We present a scheme to measure the thermal conductivity of individual nanowires using temperature-dependent and microphotoluminescence spectroscopy. The CdS nanowires suspended over trenches in silicon substrate were excited with a focused laser beam in confocal configuration. The photoluminescence at the laser spot gave a measure of the local temperature rise determined by the excitation laser intensity and the thermal conductance of the nanowires. By obtaining the temperature gradient across the nanowire and the length of the suspended segment, the thermal conductivity of CdS nanowires with diameters in the range of 200–400 nm was extracted to be in the range of 4.9–6.2 W/m K.
Vortex ring with swirl: A numerical study
Authors: Cheng M. , Lou J. , Lim T. T.
Published: September 2010

In this paper, we use a lattice Boltzmann method to study the effect of swirl on the dynamics of an isolated three-dimensional vortex ring in a viscous incompressible fluid. We focus on a fixed Reynolds number of 800 and vary swirl magnitude and vortex core size. Results show that increasing swirl for a fixed core size or increasing core size for a fixed swirl causes vortex ring to slow down or even travel backward initially. A simplified physical explanation for this dynamic behavior is proposed. Our results further show that while a weak swirl causes vortex filaments to undergo helical winding, a sufficiently strong swirl transforms these windings into convoluted three-dimensional vortex structure with vortex loops trailing behind it. Each of these vortex loops may reconnect with itself, through the process of vortex reconnection, to form a ringlet.
Nondisturbing quantum measurements
Authors: Heinosaari Teiko , Wolf Michael M.
Published: September 2010

We consider pairs of discrete quantum observables (POVMs) and analyze the relation between the notions of nondisturbance, joint measurability, and commutativity. We specify conditions under which these properties coincide or differ—depending, for instance, on the interplay between the number of outcomes and the Hilbert space dimension or on algebraic properties of the effect operators. We also show that (non-)disturbance is, in general, not a symmetric relation and that it can be decided and quantified by means of a semidefinite program.
Communication: Resolving the vibrational and configurational contributions to thermal expansion in isobaric glass-forming systems
Authors: Potuzak Marcel , Mauro John C. , Kiczenski T. J. , Ellison Adam J. , Allan Douglas C.
Published: September 2010

A fundamental understanding of isobaric thermal expansion behavior is critical in all areas of glass science and technology. Current models of glass transition and relaxation behavior implicitly assume that the thermal expansion coefficient of glass-forming systems can be expressed as a sum of vibrational and configurational contributions. However, this assumption is made without rigorous theoretical or experimental justification. Here we present a detailed statistical mechanical analysis resolving the vibrational and configurational contributions to isobaric thermal expansion and show experimental proof of the separability of thermal expansion into vibrational and configurational components for Corning Jade® glass.
Orientation-dependent charge carrier confinement in a nanopatterned silicon film
Authors: Liu Zheng , Duan Wenhui , Gu Bing-Lin , Wu Jian
Published: September 2010

From first-principles calculations, we find that in a (110) Si film with surface etching along the [001] direction, the holes can be confined underneath the patterned layer. This effect arises from the interplay between the anisotropic carriers and the patterning-induced quantum confinement. An anisotropy coefficient K=mz/my, which is the ratio between the out-of-plane effective mass and the in-plane effective mass of the charge carriers in the film, is introduced to explain the orientation dependence. We propose that a modulation-dopinglike effect can be achieved in the (110) nanopatterned Si film by selective doping in the top patterned layer.
The Pressure Dependance of Ion-Molecule Reaction Rate Coefficients: CH3+ + HCN/He
Authors: Gilbert RG , McEwan MJ
Published: September 2010

Illustrative calculations are presented on the application to termolecular ion-molecule reactions of methods recently developed for the study of fall-off effects in neutral thermal unimolecular reactions. The energy-dependent microscopic reaction rate, k(E), is obtained from RRKM theory with activated complex parameters first estimated by using ab initio and spectroscopic data and then refined to yield the appropriate pressure-saturated rate. The collisional energy transfer probability distribution function, P(E,E′), is obtained by fitting the fall-off data, guided by information from trajectory calculations. Overall rate coefficients are computed from accurate solutions to the appropriate integral master equation. The illustrative calculations are for the CH3+ + HCN+He → C2H4N+ +He system. It is shown that pressure-dependent data for ion-molecule systems can yield reliable information on P(E,E′). Collisions with the bath gas (He) are comparatively weak, with the average downward energy transferred per collision being c. 8 kJ mol-1. The product of the reaction before any isomerization can occur is shown to be protonated
methyl isocyanide , H3CNCH+.
Structual Studies of Some 2,6(2′,6′)-Halogen-Substituted Biphenyl Derivatives
Authors: Field LD , Skelton BW , Sternhell S , White AH
Published: September 2010

Single-crystal X-ray structure determinations have been carried out at 295 K on a number of biphenyl derivatives substituted with chlorine or bromine in the 2- and 6-positions in order to ascertain the effect of substitution on the torsion angle about the central bond. 2,2′,6,6′- Tetrachlorobiphenyl, (1), is orthorhombic, P nca, a 12.35(1), b
10.521(7), c 9.390(8)Ǻ, Z 4; the structure was refined to a residual of R 0.040 for No 528 independent 'observed' reflections. The interplanar dihedral angle, θ, is 81.7°. 4′-Bromo-2,4,6-trichlorobiphenyl, (2), is monoclinic, C2/c, a 19.27(1), b 7.940(2), c 33.315(8)Ǻ, β 90.93(6)°, Z 16; R 0.036 for No 1795 with θ 84.3 and 80.6° for the two independent molecules. 2,2′,4,4′,6,6′-Hexabromobiphenyl, (3), is orthorhombic, P nca, a 14.48(1), b 12.71(1), c 8.534(7)Ǻ; R 0.044 for No 693
with θ 83.0°. 2,4,4′,6-Tetrabromobiphenyl, (4), is triclinic, Pī, with a 8.14(1), b 10.74(2), c 35.42(4)Ǻ, α 87.87(10), β
79.39(10), γ 63.55(10)°, Z 8; R 0.049 for No 3962, with θ 89.8, 80.7 86.9, 83.6°, for the four independent molecules. Steric interactions between the substituents ortho to the central inter-ring bond are not the sole determinant of the geometry of these compounds in the solid state. The pairs (1) and (3), and (2) and (4), are pseudo-isostructural in each case.
Organomercury Compounds. XXVII. The Synthesis and Properties of Some Carboxylato- and Carboxy-pyridinylmercurials
Authors: Deacon GB , Stretton GN
Published: September 2010

Decarboxylation of mercuric pyridine-2,3-dicarboxylate in hot dimethyl sulfoxide or hexamethylphosphoramide gives a mixture of 2-carboxylatopyridin-3-ylmercury(II) (major product) and 3- carboxylatopyridin-2-ylmercury(II) (minor product). The mixture reacts ( i ) with acidified halide ions ( Cl - or I-) to yield a mixture of the corresponding carboxypyridinyl ( halogeno )mercury(II) derivatives, (ii) with tribromide ions to give the bromo ( carboxypyridinyl )mercury(ii) complexes, 3-bromopyridine-2-carboxylic acid, and 2-bromopyridine-3- carboxylic acid, and (iii) with iodide ions in hot aqueous acetic acid to yield bis (2-carboxypyridin-3-yl)mercury(II) hydrogen triiodomercurate (II). Solutions of the last compound in dimethyl sulfoxide deposit bis (2-carboxypyridin-3-yl)mercury(II). Reaction of pyridine-2,3-dicarboxylate ions with mercuric acetate in boiling aqueous acetic acid at pH 5.0-5.8 gives mercurated acetic acid as the sole organometallic product, and the reported1 decarboxylation yielding 3-carboxylatopyridin-2-ylmercury(II) is not observed.
Formation of Thioamide Derivatives from Reactions of Isothiocyanates with Oxazol-2-amines
Authors: Crank G , Khan HR
Published: September 2010

4-Substituted oxazol-2-amines react with isothiocyanates to give products having a thioamide function at C5. The reaction is considered to be an electrophilic process in competition with the usual reaction of the amino group with the isothiocyanate . The nature of the isothiocyanate and the type of substituent at C4 affect the amount of the thioamide product formed. Some chemical properties of the thioamides are also investigated.
Heterocyclic Amplifiers of Phleomycin. VI. Some Phenylpurines, Phenylpteridines, Phenylquinazolines and Related Compounds
Authors: Brown DJ , Mori K
Published: September 2010

Synthetic routes are described to a series of 2-, 6- and 8- phenylpurines , each with an appropriate S-or NH-linked side chain elsewhere in the molecule; to 2- and 4-phenylpteridines, each with a similar side chain and some with two additional C-methyl groups, to 2- and 4-phenylquinazolines, each equipped with an analogous side chain; and to two pyridinyl analogues of the above. Three of the above components are shown to have considerable activity as amplifiers of phleomycin -G in an in vitro bacterial system.
The Oxidation of (±)-Reticuline as Studied by E.S.R Spectroscopy
Authors: Hewgill FR , Pass MC
Published: September 2010

E.s.r. spectra obtained by oxidation of reticuline and closely related compounds in a flow system
with cerium(IV) show chiefly the aryloxy radical derived from the 1-benzyl c-ring. The 4′-ethoxy homologue of norreticuline shows both A- and C-ring radicals in roughly equal proportions. The mechanism of intramolecular coupling is discussed, and as no evidence was obtained for the occurrence of a radical substitution reaction it is concluded that radical pairing is more likely, although this apparently happens too quickly for observation of a biradical species.
Benzo[c]cinnoline Derivatives. VIII. Properties of Hydroxy- and Methoxy-benzo[c]cinnolines
Authors: Lewis GE , Lill DL
Published: September 2010

The ultraviolet-visible absorption spectra and ionization constants of the complete series of hydroxy -and methoxy-benzo [c] cinnolines are reported and discussed in relation to the efficiency of electronic interaction between each substituent and the relevant nitrogen atom of the central ring.
A Study of Chemical Reactions in Molton Sodium-Potassium Hydrogen Sulfate Eutectic. IV. The Reaction of Eight Oxalates
Authors: Sabato JO , Tariq SA
Published: September 2010

The reactions of oxalates
of ammonium, alkali metals (Li, Na and K) and alkaline earth metals (Mg, Ca, Sr and Ba ) with sodium-potassium hydrogen sulfate eutectic were investigated. Oxalic acid was found to be an intermediate product in all these reactions. Final products of the reactions as determined by thermogravimetry , differential thermal analysis, X-ray diffraction, infrared and 'wet' chemical methods consisted of a mixture of H2O, CO, CO2 and the corresponding metal sulfate. The stoichiometries of the reactions were elucidated.
The Flavonoids of Combretum quadrangulare: Crystal structures of the Polymorphic Forms of 5-Hydroxy-2-(4'-hydroxy-3',5'-dimethoxyphenyl)-3,7-dimethoxy-4H-1-benzopyran-4-one
Authors: Castleden IR , Hall SR , Nimgirawath S , Thadaniti S , White AH
Published: September 2010

The following substituted 2-phenyl-4H-1-benzopyran-4-ones have been isolated from the dried flowers of Combretum quadrangulare Kurz ( Combretaceae ): 5-hydroxy-3,3′,4′,5′,7-pentamethoxy ( combretol ) (1),
3′,5-dihydroxy-3,4′,7-trimethoxy ( ayanin ) (2) and 4′,5-dihydroxy- 3,3′,5′,7-tetramethoxy (3). The last substance (3) was obtained as a mixture of two polymorphic forms (α and β) each of which was characterized by X-ray diffraction. Diffractometer data at 295 K were refined by full matrix least squares to residuals of 0.043 (1181 'observed' reflections) for the α-phase and 0.044 (1421) for the β phase of (3). Crystals of the α-phase of (3) are triclinic, Pī, a 12.663(6), b 9.592(4), c 7.444(4) Ǻ, α 102.48(3), β 101.39(4),
γ 91.72(4)°,Z 2. Crystals of the β-phase of (3) are monoclinic P21/n, a 17.139(8), b 12.728(6), c 7.845(7) Ǻ, β 95.07(6)°, Z 4. An unambiguous synthesis of (3) was also achieved.