bluuebunny/crossref_metadata_2025 huggingface dataset:
Prolonged grief among traumatically bereaved relatives exposed and not exposed to a tsunami
Authors: Johannesson Kerstin Bergh , Lundin Tom , Hultman Christina M. , Fröjd Thomas , Michel Per‐Olof
Published: August 2011

Numerous studies on the mental health consequences of traumatic exposure to a disaster compare those exposed to those not exposed. Relatively few focus on the effect of the death of a close relative caused by the disaster—suffering a traumatic bereavement. This study compared the impact on 345 participants who lost a close relative in the 2004 Indian Ocean tsunami, but who were themselves not present, to 141 who not only lost a relative, but also were themselves exposed to the tsunami. The focus was on psychological distress assessed during the second year after the sudden bereavement. Findings were that exposure to the tsunami was associated with prolonged grief (B = 3.81) and posttraumatic stress reactions (B = 6.65), and doubled the risk for impaired mental health. Loss of children increased the risk for psychological distress (prolonged grief: B = 6.92; The Impact of Event Scale‐Revised: B = 6.10; General Health Questionnaire‐12: OR = 2.34). Women had a higher frequency of prolonged grief. For men, loss of children presented a higher risk for prolonged grief in relation to other types of bereavement (B = 6.36 vs. loss of partner). Further long‐term follow‐up could deepen the understanding of how recovery after traumatic loss is facilitated.
PEGylated Anti‐MUC1 Aptamer‐Doxorubicin Complex for Targeted Drug Delivery to MCF7 Breast Cancer Cells
Authors: Tan Lihan , Neoh Koon Gee , Kang En‐Tang , Choe Woo Seok , Su Xiaodi
Published: August 2011

Targeted drug delivery is especially important in cancer treatment as many anti‐cancer drugs are non‐specific and highly toxic to both cancer and normal cells. The targeted drug delivery of DOX to the MUC1‐expressing breast cancer cell line (MCF7) was obtained using APT as a carrier. Modification of the APT‐DOX complex by PEG increases the survivability of the macrophage control (RAW 264.7) by about six‐fold as compared to free DOX treatment without significantly affecting the cytotoxicity toward the target cell line. Thus, PEG‐APT‐DOX is potentially a new therapeutic agent for targeted drug delivery to MUC1‐expressing cell lines.

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Electrostatic Similarity Determination Using Multiresolution Analysis
Authors: Hakkoymaz Huseyin , Kieslich Chris A. , Jr. Ronald D. Gorham , Gunopulos Dimitrios , Morikis Dimitrios
Published: August 2011

Molecular similarity is an important tool in protein and drug design for analyzing the quantitative relationships between physicochemical properties of two molecules. We present a family of similarity measures which exploits the ability of wavelet transformation to analyze the spectral components of physicochemical properties and suggests a sensitive way for measuring similarities of biological molecules. In order to investigate how effective wavelet‐based similarity measures were against conventional measures, we defined several patterns which involve scalar or topological changes in the distribution of electrostatic properties. The wavelet‐based measures were more successful in discriminating these patterns in contrast to the current state‐of‐art similarity measures. We also present the validity of wavelet‐based similarity measures through the hierarchical clustering of two protein datasets consisting of families of homologous domains and alanine scan mutants. This type of similarity analysis is useful for protein structure‐function studies and protein design.
AMBIT‐SMARTS: Efficient Searching of Chemical Structures and Fragments
Authors: Jeliazkova Nina , Kochev Nikolay
Published: August 2011

We present new developments in the AMBIT open source software package for efficient searching of chemical structures and structural fragments. AMBIT‐SMARTS is a Java based software built on top of The Chemistry Development Kit. The AMBIT‐SMARTS parser implements the entire SMARTS language specification with several syntax extensions that enable support for custom modifications introduced by third party software packages such as OpenEye, MOE and OpenBabel. The goal of yet another open‐source SMARTS parser implementation is to achieve better performance and compatibility with multiple existing flavours of the SMARTS language, as well as to provide utilities for running efficient SMARTS queries in large structural databases. We describe a combination of approaches towards lowering the computational cost and improving the response time of substructure queries. An exhaustive comparison of the AMBIT algorithm with several subgraph isomorphism implementations is performed. To demonstrate the performance of the entire system from an end‐user point of view, response time statistics for Web service substructure search queries against a database of 4.5 M structures are also reported. The package has wide applicability in the implementation of various chemoinformatics tasks. It has already been used in several projects dealing with descriptor calculation and predictive algorithms, database queries, web applications and web services.
Development and characterization of organoclay‐filled polyoxymethylene nanocomposites for high performance applications
Authors: Jose Ajith James , Alagar M.
Published: August 2011

The present work focuses on the preparation and characterization of organo‐modified fluorohectorite (OFH) clay filled polyoxymethylene (POM) nanocomposites by melt mixing method. The dispersion of OFH clay in the polymer matrix was confirmed by X‐ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM) analysis. The surface properties of the nanocomposites, assessed by contact angle measurements, showed increase in hydrophobicity relative to the neat polymer. From the measured contact angle values, various surface parameters such as total surface free energy, interfacial free energy, work of adhesion, spreading coefficient, and Girifalco‐Good's interaction parameter were calculated. The thermal, mechanical, and dielectric properties of the nanocomposites were found to be improved by the incorporation of OFH clay into the POM matrix. The aging studies of the nanocomposites carried out by immersing the samples in various solvents showed an increase in the retention of mechanical property by the addition of OFH clay into the POM matrix. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Synthesis and characterization of conducting gas barrier polyacrylonitrile/graphite nanocomposites
Authors: Prusty Gyanaranjan , Swain Sarat K
Published: August 2011

Graphite platelets were expanded by functionalization with inorganic acids followed by strong thermal treatment. The expanded graphite (EG) was exfoliated on the polyacrylonitrile (PAN) matrix through in situ emulsion sonication technique with different proportions of EG. The Ultraviolet‐visible (UV) spectroscopy revealed the interaction between EG and PAN matrix. In Fourier Transform Infrared spectroscopy (FTIR), the chemical interaction between EG and the cyanide group of PAN was evidenced to the formation of PAN/EG composites. The X‐ray diffraction pattern of raw graphite (RG), expanded graphite (EG), polyacrylonitrile (PAN), and PAN/EG nanocomposites were evidenced the dispersion of EG with the PAN matrix. The morphology of EG, PAN, and PAN/EG composites were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The tensile strength of PAN/EG nanocomposite was measured and found to be increased with increase in EG concentrations. The conductivity and impedance of composites were measured as function of EG concentration. It was found that, conductivity of composites gradually increased with the increase in EG loading. Oxygen permeability of PAN/EG was reduced substantially with rise of EG proportion. To investigate the flame retardancy behavior of PAN/EG nanocomposites, the limiting oxygen indexes were calculated. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Preparation of silk fibroin–poly(ethylene glycol) conjugate films through click chemistry
Authors: Sampaio Sandra , Miranda Teresa M. R. , Santos Jorge G. , Soares Graça M. B.
Published: August 2011

Azide silk fibroin (azido SF) and alkyne terminal poly(ethylene glycol) (PEG) 2000 (acetylene‐terminal PEG 2000) were synthesized. Azido SF was reacted with acetylene‐terminal PEG 2000 to produce films via a copper‐mediated 1,3‐cycloaddition (‘click’ chemistry) generating a triazole linkage as the networking forming reaction. Through click chemistry, novel silk‐based films with various weight ratios were prepared and investigated. Fourier transform infrared, X‐ray diffraction and differential scanning calorimetry analyses showed that the ordered association of the PEG molecules is strongly constrained by the presence of the SF molecules and crosslinking and that the presence of acetylene‐terminal PEG 2000 in the films induced crystallization to a β‐sheet of SF chains. Water content and contact angle measurements indicated that the hydrophilicity of the films increased compared with SF. SF–PEG films exhibited smooth and rough structures, depending on degree of crosslinking and on the weight ratio of SF and PEG, as shown by scanning electron microscopy. Copyright © 2011 Society of Chemical Industry
Theoretical analysis on geometries and electronic structures of antiaromatic pentalene and its N‐substituted derivatives: monomer, oligomers and polymer
Authors: Liu Binyao , Shen Wei , Xie Xiaohua , Deng Lidan , Li Ming
Published: August 2011

The antiaromatic compounds have received a great deal of attention for several decades because of their unusual electronic structures. The electronic structures and properties of antiaromatic pentalene and its six nitrogen heterocyclic derivatives were systematically studied by the density functional theory at the Becke, three‐parameter, Lee–Yang–Parr level with 6‐31G* basis set. The results indicated that all the monomers have stable singlet states and remarkable bond‐length alternations. From the dimer to polymer in those molecules, pentalene(P), cyclopenta[b]pyrrole(CPP), cyclopenta[d]imidazole(CPI), pyrrolo[2,3‐b]pyrrole(PP1) and pyrrolo[3,2‐d]imidazole(PI) are stable diradical structures; pyrrolo[3,2‐b]pyrrole (PP2) and imidazo[4,5‐d]imidazole(II) are stable singlet ground states. The electronic properties including bond length, bond‐length alternation, electron density at bond critical points, Wiberg bond index and nucleus‐independent chemical shift were analyzed. It was found that in diradical molecules the bond‐length alternations are diminished, the charge tends to equilibrate, the π‐electron delocalization and conjugation are strengthened. The electronic properties of singlet ground state molecules have nearly no variations from monomers to polymers. The band structure analysis shows that diradical structure molecules have small band gaps (<1.0 eV), wide bandwidth and small effective masses of holes and electrons which suggest that diradical structure molecules are very good candidates for conductive materials. Copyright © 2011 John Wiley & Sons, Ltd.
Efficacy of intratracheal instillation of a meropenem/perfluorochemical suspension in acute lung injury
Authors: Jeng Mei‐Jy , Soong Wen‐Jue , Chiou Shr‐Yun , Wu Yu‐Tse , Tsai Tung‐Hu , Lin Chia‐Chun , Yang Chia‐Feng , Tsao Pei‐Chen , Lee Yu‐Sheng
Published: August 2011

Perfluorochemical (PFC) is theoretically a good vehicle for delivering biological agents to the lungs. This study was designed to investigate the efficacy of intratracheal (IT) instillation of meropenem using PFC liquid as a vehicle in a piglet model of acute lung injury (ALI). Eighteen piglets were injured with lung lavages to induce ALI, and randomly assigned to intravenous (IV) infusion or IT instillation groups, the latter using either PFC or normal saline (NS) as a delivery vehicle for meropenem. Blood samples were obtained at 0, 15, 30, and 60 min, and then hourly for 6 hr. Sera and extracts of lung tissues were assayed for meropenem content using high‐performance liquid chromatography. We found that the IV group had significantly higher serum concentrations of meropenem during the first hour after dosing (P < 0.05). There was no significant difference between IT‐PFC and IT‐NS groups regarding changes in serum meropenem concentrations during the experimental period. Meropenem content in lung tissue was highest in the IT‐PFC group, lower in the IT‐NS group, and undetectable in the IV group (P < 0.05). The IT‐NS group had the highest peak inspiratory pressure (P < 0.05), but there were no significant differences in other cardiopulmonary parameters among the three groups studied. In conclusion, meropenem can be safely administered to injured lungs by IT instillation in a meropenem/PFC suspension. Using PFC liquid as an IT vehicle to carry meropenem provides better pulmonary drug depositions than IV injection or IT instillation with NS in ALI. Pediatr Pulmonol. 2012; 47:189–198. © 2011 Wiley Periodicals, Inc.
Effects of Different Garlic‐derived Allyl Sulfides on Peroxidative Processes and Anaerobic Sulfur Metabolism in Mouse Liver
Authors: Iciek Małgorzata B. , Kowalczyk‐Pachel Danuta , Kwiecień Inga , Dudek Magdalena B.
Published: August 2011

Biological activity of garlic has been attributed to organosulfur compounds, most of all to oil‐soluble allyl sulfides, such as diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS). This study evaluated the effectiveness of garlic‐derived allyl sulfides in influencing peroxidative processes, levels of thiols and sulfane sulfur and its metabolic enzymes in normal mouse liver cells. Various allyl sulfides (DAS, DADS and DATS) dissolved in corn oil were given intraperitoneally to mice for 10 days. After sacrificing the mice, biochemical assays were performed in liver homogenates and in plasma in order to establish liver function. All allyl sulfides under study had a beneficial effect in the mouse liver since they decreased reactive oxygen species and malondialdehyde levels and increased glutathione S‐transferase activity and non‐protein sulfhydryl group level. Moreover, DADS and DATS elevated total sulfane sulfur pool and activity of sulfane sulfur biosynthetic enzymes. The increase in sulfane sulfur level entailed augmentation of its antioxidant and regulatory capacities. Garlic‐derived allyl sulfides exhibited antioxidant action in the liver and elevated anaerobic cysteine metabolism leading to the formation of sulfane sulfur‐containing compounds. Thus, DADS and DATS showed beneficial action in the liver, which can be used for protection of normal liver cells during chemotherapy or for alleviation of liver damage. Copyright © 2011 John Wiley & Sons, Ltd.
The differing effects of agent and founder CEOs on the firm's market expansion
Authors: Souder David , Simsek Zeki , Johnson Scott G.
Published: August 2011

This paper builds and tests the thesis that CEO influence evolves differently for founders and agents. We theorize that at the beginning of their tenures, founder CEOs can pursue market expansion more aggressively than agent CEOs, because they take office with the combination of motivation, power, and requisite knowledge that agent CEOs build over time. Subsequently, however, founder CEOs have less access to the administrative infrastructure necessary to sustain a growing firm, making them less able than agent CEOs to continue market expansion mid‐tenure and more severely constrained by market complexity. A longitudinal study of cable television operators confirms that the firm's market expansion follows an inverted U‐shape for agents and a downward slope for founders, while market complexity reduces market expansion, especially for founders. Copyright © 2011 John Wiley & Sons, Ltd.
Exposure, infection, systemic cytokine levels and antibody responses in young children concurrently exposed to schistosomiasis and malaria
Authors: IMAI NATSUKO , RUJENI NADINE , NAUSCH NORMAN , BOURKE CLAIRE D. , APPLEBY LAURA J. , COWAN GRAEME , GWISAI REGGIS , MIDZI NICHOLAS , CAVANAGH DAVID , MDULUZA TAKAFIRA , TAYLOR DAVID , MUTAPI FRANCISCA
Published: August 2011

Despite the overlapping distribution ofSchistosoma haematobiumandPlasmodium falciparuminfections, few studies have investigated early immune responses to both parasites in young children resident in areas co-endemic for the parasites. This study measures infection levels of both parasites and relates them to exposure and immune responses in young children. Levels of IgM, IgE, IgG4 directed against schistosome cercariae, egg and adult worm and IgM, IgG directed againstP. falciparumschizonts and the merozoite surface proteins 1 and 2 together with the cytokines IFN-γ, IL-4, IL-5, IL-10 and TNF-αwere measured by ELISA in 95 Zimbabwean children aged 1–5 years. Schistosome infection prevalence was 14·7% and that ofPlasmodiuminfection was 0% in the children. 43. 4% of the children showed immunological evidence of exposure to schistosome parasites and 13% showed immunological evidence of exposure toPlasmodiumparasites. Schistosome–specific responses, indicative of exposure to parasite antigens, were positively associated with cercariae-specific IgE responses, whilePlasmodium-specific responses, indicative of exposure to parasite antigens, were negatively associated with responses associated with protective immunity againstPlasmodium. There was no significant association between schistosome-specific andPlasmodium-specific responses. Systemic cytokine levels rose with age as well as with schistosome infection and exposure. Overall the results show that (1) significantly more children are exposed to schistosome andPlasmodiuminfection than those currently infected and; (2) the development of protective acquired immunity commences in early childhood, although its effects on infection levels and pathology may take many years to become apparent.
Association of MMP-2 and MMP-9 with clinical outcome of neurocysticercosis
Authors: VERMA AVANTIKA , PRASAD KASHI N. , NYATI KISHAN K. , SINGH SATYENDRA K. , SINGH ALOUKICK K. , PALIWAL VIMAL K. , GUPTA RAKESH K.
Published: August 2011

Matrix metalloproteinases (MMPs) are the major endopeptidases involved in proteolysis of blood brain barrier (BBB) during central nervous system (CNS) infections. The present study detected serum levels and activities of MMP-2 and MMP-9 in patients with neurocysticercosis (NCC) and their association with symptomatic disease. In total, 68 individuals with NCC (36 symptomatic patients with active seizures and 32 asymptomatic individuals) and 37 healthy controls were enrolled for the study. Serum MMP-2 and MMP-9 levels and their activities were measured by ELISA and gel zymography respectively. Mean serum MMP-2 levels (ng/ml) were higher both in asymptomatic and symptomatic NCC cases compared to healthy controls. However, significantly higher levels of serum MMP-9 (ng/ml) were detected only in symptomatic NCC patients compared to asymptomatic NCC cases and healthy controls. Levels of both MMPs positively correlated with symptomatic NCC. Serum MMP-2 activities were significantly higher in symptomatic and asymptomatic NCC compared to healthy controls whereas serum MMP-9 activity was significantly associated with symptomatic NCC compared to healthy controls and asymptomatic NCC. In conclusion, the elevated level of MMP-9 in serum appears to play an important role in the development of symptoms i.e. active seizures in patients with NCC. However, further studies are needed to elucidate its precise role in disease pathogenesis.
A current‐matrix model for metallic and dielectric postwall waveguides
Authors: Coenen T. J. , Bekers D. J. , Tauritz J. L. , van Vliet F. E.
Published: August 2011

Waveguide structure integration in planar substrates for use in microwave components has received considerable attention in recent years. Waveguides with side walls consisting of cylindrical posts (postwall waveguides or PWWGs) are of interest, since they are compatible with standard PCB fabrication technology and exhibit low loss. In this paper we present an electromagnetic model for PWWG building blocks, whose characteristics are described entirely in terms of equivalent electric and magnetic surface currents at predefined port interfaces consistent with Lorentz's reciprocity theorem. Introducing input and output surface currents, we determine the response of a block for a given port excitation. The expansion of the currents in terms of suitable bases results in a matrix that relates input and output currents. The scattering parameters of a building block are determined by expressing waveguide modes in terms of these bases. This facilitates the future integration of PWWG components in a microwave circuit simulator. We validate our model by comparing the results for simulated and measured uniform PWWGs implemented with metallic and dielectric posts.
An attempt to validate HF propagation prediction conditions over Sub‐Saharan Africa
Authors: Tshisaphungo Mpho , McKinnell Lee‐Anne , Magnus Lindsay , Habarulema John Bosco
Published: August 2011

Ionospheric behavior plays an important role in high‐frequency (HF) radio propagation, which subsequently provides an opportunity for studying ionospheric variability and space weather effects. The continuous change in ionospheric conditions caused by space weather strongly affects HF propagation. The use of HF communication is still very relevant over the African continent, as seen by the requirements for services provided by the Regional Warning Center for Space Weather in Africa, and this has necessitated an investigation into the prediction capabilities of the existing HF propagation models currently used over this region. This paper presents the validation of HF propagation conditions through the ionosphere by using the Ionospheric Communication Enhanced Profile Analysis and Circuit (ICEPAC) model with real‐time data from international beacons located in Africa. The HF propagation results presented are for the circuits Ruaraka (5Z4B), Kenya (1.24°S, 36.88°E), and Pretoria (ZS6DN), South Africa (25.45°S, 28.10°E) to Hermanus (ZS1HMO), South Africa (34.27°S, 19.12°E). The potential of this model as compared to real‐time data in terms of propagation condition predictions is illustrated. An attempt to draw conclusions for the future improvement of HF propagation models is also presented. Results show that ICEPAC performs better for the 5Z4B‐ZS1HMO than for the ZS6DN‐ZS1HMO circuit, although it does, in general, provide a low‐accuracy prediction compared to the real‐time data. Thus certain parameters need to be investigated further for future improvement in the performance of the ICEPAC model over Africa.
Distribution of Quaternary deformation in the central Main Ethiopian Rift, East Africa
Authors: Agostini Andrea , Bonini Marco , Corti Giacomo , Sani Federico , Manetti Piero
Published: August 2011

The Main Ethiopian Rift (MER) is a narrow continental rift characterized by an along‐axis variation in rift evolution, with early stages in the south evolving to incipient breakup in the north. Although distribution and style of Quaternary volcanotectonic deformation is well known in the northern rift sector, knowledge of these characteristics is comparatively less constrained southward. In this paper we present the results of a field structural study carried out to better constrain the time‐space distribution of faulting in the central sector of the MER (central MER). The new field structural data coupled with new 14C radiometric dating of faulted rocks suggest a localization of faulting at both rift margins of the central MER, where radiometric dating of faulted material has allowed establishing a Late Pleistocene–Holocene activity of border faults. Conversely, in‐rift faulting (Wonji Fault Belt (WFB)) is subordinate highlighting a major difference with the northern sector of the MER where deformation is essentially accommodated in the axial zone. This is consistent with an along‐axis variation in rift evolution, showing the central MER less evolved than the northern rift sector. Inversion of cumulative fault slip data reveals a variation in the extension direction between the rift margins (N105°–110°E) and the rift floor (N90°–95°E), which accords well with the current Nubia‐Somalia plate kinematics. The variation in extension direction across the rift could manifest a slip partitioning between the boundary faults and in‐rift WFB faults.
Effects of stream discharge, alluvial depth and bar amplitude on hyporheic flow in pool‐riffle channels
Authors: Tonina Daniele , Buffington John M.
Published: August 2011

Hyporheic flow results from the interaction between streamflow and channel morphology and is an important component of stream ecosystems because it enhances water and solute exchange between the river and its bed. Hyporheic flow in pool‐riffle channels is particularly complex because of three‐dimensional topography that spans a range of partially to fully submerged conditions, inducing both static and dynamic head variations. Hence, these channels exhibit transitional conditions of streambed pressure and hyporheic flow compared to previous studies of fully submerged, two‐dimensional bed forms. Here, we conduct a series of three‐dimensional simulations to investigate the effects of bed topography, depth of alluvium, and stream discharge on hyporheic flow in pool‐riffle reaches with variable bed form submergence, and we propose three empirical formulae to predict the mean depth of hyporheic exchange and characteristic values of the residence time distribution (mean and standard deviation). Hyporheic exchange is predicted with a three‐dimensional pumping model, and hyporheic flow is modeled as a Darcy flow. We find that the hyporheic residence time is well approximated by a lognormal distribution for both partially and entirely submerged pool‐riffle topography, with the parameters of the distribution defined by the mean and variance of the log‐transformed residence time. Depth of alluvium has a substantial effect on hyporheic flow when alluvial depth is less than a third of the bed form wavelength for the conditions examined.
The transient response of the Southern Ocean pycnocline to changing atmospheric winds
Authors: Jones Daniel C. , Ito Takamitsu , Lovenduski Nicole S.
Published: August 2011

The vertical density structure of the Southern Ocean is dynamically linked to wind stress at the surface, but the nature of this coupling is not fully understood. Observations from the last several decades show a significant increase in the strength of westerly winds over the Southern Ocean, but an appreciable change in the tilt of constant density surfaces (isopycnals) has not yet been detected there. Using a combination of theory and idealized numerical simulations, we show that the response of the density structure occurs on centennial timescales, making it difficult to detect significant changes with a few decades of hydrographic observations. Dynamic coupling between the circumpolar current and northern basins regulates the slow adjustment of the density structure. Our results provide a new interpretation for recent observations and highlight the importance of the interaction between regional Southern Ocean dynamics and global ocean circulation.
Sex and Type 2 Diabetes: Obesity‐Independent Effects on Left Ventricular Substrate Metabolism and Relaxation in Humans
Authors: Peterson Linda R. , Saeed Ibrahim M. , McGill Janet B. , Herrero Pilar , Schechtman Kenneth B. , Gunawardena Ratnasiri , Recklein Carol L. , Coggan Andrew R. , DeMoss Amanda J. , Dence Carmen S. , Gropler Robert J.
Published: August 2011

Patients with type 2 diabetes (T2DM), particularly women, are at risk for heart failure. Myocardial substrate metabolism derangements contribute to cardiac dysfunction in diabetic animal models. The purpose of this study was to determine the effects of diabetes and sex on myocardial metabolism and diastolic function in humans, separate from those of obesity. Thirty‐six diabetic subjects (22 women) and 36 nondiabetic, BMI‐matched subjects (21 women) underwent positron emission tomography (myocardial metabolism) and echocardiography (structure, function). Myocardial blood flow and oxygen consumption (MVO2) were higher in women than men (P = 0.003 and <0.0001, respectively). Plasma fatty acid (FA) levels were higher in diabetics (vs. obese, P < 0.003) and sex and diabetes status interacted in its prediction (P = 0.03). Myocardial FA utilization, oxidation, and esterification were higher and percent FA oxidation lower in diabetics (vs. obese, P = 0.0004, P = 0.007, P = 0.002, P = 0.02). FA utilization and esterification were higher and percent FA oxidation lower in women (vs. men, P = 0.03, P = 0.01, P = 0.03). Diabetes and sex did not affect myocardial glucose utilization, but myocardial glucose uptake/plasma insulin was lower in the diabetics (P = 0.04). Left ventricular relaxation was lower in diabetics (P < 0.0001) and in men (P = 0.001), and diabetes and sex interacted in its prediction (P = 0.03). Sex, T2DM, or their interaction affect myocardial blood flow, MVO2, FA metabolism, and relaxation separate from obesity's effects. Sexually dimorphic myocardial metabolic and relaxation responses to diabetes may play a role in the known cardiovascular differences between men and women with diabetes.
Obesity Disparities in Preventive Care: Findings From the National Ambulatory Medical Care Survey, 2005–2007
Authors: Hernandez‐Boussard Tina , Ahmed Shushmita M. , Morton John M.
Published: August 2011

Obesity and its consequences are a major health concern. There are conflicting reports regarding utilization of preventive health‐care services among obese patients. Our objective was to determine whether obese patients receive the same preventive care as normal weight patients. Weighted patient clinic visit data from the National Ambulatory Medical Care Survey (NAMCS) were analyzed for all adult patient visits with height/weight data (N = 866,415,856) from 2005 to 2007. Preventive care practice patterns were compared among different weight groups of normal, obese, and morbidly obese. Obese patients received the least number of preventive exams with a clear gradient present by weight. Obese patients were significantly less likely to receive cancer screening including breast examination (normal weight, reference, obese, odds ratio (OR), 0.8), mammogram (obese OR, 0.7), pap smear (obese OR, 0.7), pelvic exam (obese OR, 0.8), and rectal exam (obese OR, 0.7). The obese population also received less tobacco (obese OR, 0.7) and injury prevention education (obese OR, 0.7), yet significantly more diet, exercise, and weight reduction education. Significant differences in clinic practice patterns relative to normal weight patients were also evident with more physician referral (obese OR, 1.2) and less likely to see physician at the index clinic visit (obese OR, 0.8) and less likely to receive psychotherapy referral (obese OR, 0.6). Significant gaps in preventive care exist for the obese including cancer screening, tobacco cessation and injury prevention counseling, and psychological referral. Although obese patients received more weight‐related education, this emphasis may have the consequence of de‐emphasizing other needed preventive health measures.
Infrared imaging and acoustic sizing of a bubble inside a micro-electro-mechanical system piezo ink channel
Authors: van der Bos Arjan , Segers Tim , Jeurissen Roger , van den Berg Marc , Reinten Hans , Wijshoff Herman , Versluis Michel , Lohse Detlef
Published: August 2011

Piezo drop-on-demand inkjet printers are used in an increasing number of applications because of their reliable deposition of droplets onto a substrate. Droplets of a few picoliters are ejected from an inkjet nozzle at frequencies of up to 100 kHz. However, the entrapment of an air microbubble in the ink channel can severely impede the productivity and reliability of the printing system. The air bubble disturbs the channel acoustics, resulting in disrupted drop formation or failure of the jetting process. Here we study a micro-electro-mechanical systems-based printhead. By using the actuating piezo transducer in receive mode, the acoustical field inside the channel was monitored, clearly identifying the presence of an air microbubble inside the channel during failure of the jetting process. The infrared visualization technique allowed for the accurate sizing of the bubble, including its dynamics, inside the intact printhead. A model was developed to calculate the mutual interaction between the channel acoustics and the bubble dynamics. The model was validated by simultaneous acoustical and infrared detection of the bubble. The model can predict the presence and size of entrapped air bubbles inside an operating ink channel purely from the acoustic response.
Effect of strain on depairing current density in deformable superconducting thin films
Authors: Yong Huadong , Xue Feng , Zhou Youhe
Published: August 2011

The changes of the superconducting depairing current density with applied strain in superconducting films are studied theoretically in this paper. The thin film is assumed to be isotropic. Using phenomenological theory, we obtain the depairing critical current density in the presence of applied strain. The dependence of deparing current density on coupling parameters is discussed. A qualitative agreement between our theoretical predictions with reported experimental results is observed as the coupling parameters are linear function of the applied strain. The results indicate that the coupling parameters have a significant influence on the critical current density in the superconducting film.
Magnetoelectric coupling in sol-gel synthesized dilute magnetostrictive-piezoelectric composite thin films
Authors: Roy Subhasis , Chatterjee Ratnamala , Majumder S. B.
Published: August 2011

Multiferroic lead lanthanum titanate–cobalt iron oxide nano-composite thin films are synthesized by sol-gel route. A percolative distribution of cobalt iron oxide phase, with percolation threshold ∼8 vol%, is identified in these films. Large magnetoelectric coupling coefficient (∼250 mV/cm.Oe) is found in the composite films with cobalt iron oxide volume contents in the vicinity of its percolation threshold. The composite films with dilute magnetostrictive volume contents yield superior multiferroic properties to its counterparts with relatively higher magnetostrictive volume contents.
Rigorous coarse-graining for the dynamics of linear systems with applications to relaxation dynamics in proteins
Authors: Soheilifard Reza , Makarov Dmitrii E. , Rodin Gregory J.
Published: August 2011

Reduced-dimensionality, coarse-grained models are commonly employed to describe the structure and dynamics of large molecular systems. In those models, the dynamics is often described by Langevin equations of motion with phenomenological parameters. This paper presents a rigorous coarse-graining method for the dynamics of linear systems. In this method, as usual, the conformational space of the original atomistic system is divided into master and slave degrees of freedom. Under the assumption that the characteristic timescales of the masters are slower than those of the slaves, the method results in Langevin-type equations of motion governed by an effective potential of mean force. In addition, coarse-graining introduces hydrodynamic-like coupling among the masters as well as non-trivial inertial effects. Application of our method to the long-timescale part of the relaxation spectra of proteins shows that such dynamic coupling is essential for reproducing their relaxation rates and modes.
Pressure and temperature dependence of dissociative and non-dissociative electron attachment to CF3: Experiments and kinetic modeling
Authors: Shuman Nicholas S. , Miller Thomas M. , Friedman Jeffrey F. , Viggiano Albert A. , Maergoiz Anatol I. , Troe Jürgen
Published: August 2011

The kinetics of electron attachment to CF3 as a function of temperature (300–600 K) and pressure (0.75–2.5 Torr) were studied by variable electron and neutral density attachment mass spectrometry exploiting dissociative electron attachment to CF3Br as a radical source. Attachment occurs through competing dissociative (CF3 + e− → CF2 + F−) and non-dissociative channels (CF3 + e− → CF3−). The rate constant of the dissociative channel increases strongly with temperature, while that of the non-dissociative channel decreases. The rate constant of the non-dissociative channel increases strongly with pressure, while that of the dissociative channel shows little dependence. The total rate constant of electron attachment increases with temperature and with pressure. The system is analyzed by kinetic modeling in terms of statistical theory in order to understand its properties and to extrapolate to conditions beyond those accessible in the experiment.
Experimental and theoretical analysis of the rotational Raman spectrum of hydrogen molecules in clathrate hydrates
Authors: Giannasi Alessandra , Celli Milva , Zoppi Marco , Moraldi Massimo , Ulivi Lorenzo
Published: August 2011

The Raman spectra of H2 and HD molecules in simple hydrogen and binary hydrogen-tetrahydrofuran clathrate hydrates have been measured at temperatures as low as 20 K. The rotational bands of trapped molecules in simple and binary hydrates have been analyzed, and the contributions originating from hydrogen molecules in the large cages have been separated from those in the small cages. A theoretical model, consisting in rigid cages enclosing interacting hydrogen molecules, has been exploited to calculate, on the basis of quantum mechanics, the Raman intensity of the rotational transitions for up to two interacting molecules in one cage. A comparison with experiment leads to a clear interpretation of sidebands appearing in the Raman rotational lines. The quantitative agreement between theory and experiment obtained in some cases clarifies the importance of the choice of the interaction potential, and of the proton disorder in the clathrate crystal.
Isotropic reorientations of fullerene C70 triplet molecules in solid glassy matrices revealed by light-induced electron paramagnetic resonance
Authors: Uvarov Mikhail N. , Kulik Leonid V. , Doktorov Alexander B. , Dzuba Sergei A.
Published: August 2011

Continuous-wave X-band electron paramagnetic resonance (EPR) of fullerene C70 molecules excited to a triplet state by continuous light illumination was studied in molecular glasses of o-terphenyl and cis/trans-decaline and in the glassy polymers polymethylmethacrylate (PMMA) and polystyrene (PS). Above ∼100 K, a distinct narrowing of EPR lineshape of the triplet was observed, which was very similar for all systems studied. EPR lineshape was simulated reasonably well within a framework of a simple model of random jumps, which implies that the C70 molecule performs isotropic orientational motion by sudden jumps of arbitrary angles. In simulations, a single correlation time τc was used, varying in the range of 10−7−10−8 s. Near and below 100 K electron spin echo (ESE) signals were also obtained which were found to decay exponentially. Correlation times τc obtained from simulation of the EPR spectra in the slow-motion limit (τc close to 10−7 s) turned out to be in good agreement with the phase memory times TM of the ESE decay, which additionally supports the employed simple model. The observed motional effects provide evidence that the nanostructure of the solid glassy media of different origins is soft enough to allow a large asymmetric C70 molecule to reorient rapidly. Except for the EPR spectra of the triplet, in the center of the spectra, a small admixture of a narrow line was also observed; its possible nature is briefly discussed.
Unipolar resistive switching mechanism speculated from irreversible low resistance state of Cu2O films
Authors: Hong Sahwan , Xiao Long Deng , Hwang Inrok , Kim Jin-Soo , Chang Park Yun , Kang Sung-Oong , Ho Park Bae
Published: August 2011

We observed cathode-interfaced electroreduction and a variation of oxygen content in an irreversible low resistance state of highly oriented cuprous oxide (Cu2O) films. These local microstructural and stoichiometric changes in hard breakdown of film allow speculation on the unipolar resistive switching mechanism: formation of metallic filaments originating from generation/migration of oxygen ions (O2−) from the cathode and release of oxygen gas through the anode. Based on the as-proposed switching model, endurance switching properties could be modulated from tens up to over 104 switching cycles by controlling ambient gas or the interface between Cu2O and anode.
Phase operators, phase states and vector phase states for SU3 and SU2, 1
Authors: Daoud M. , Kibler M. R.
Published: August 2011

This paper focuses on phase operators, phase states, and vector phase states for the sl3 Lie algebra. We introduce a one-parameter generalized oscillator algebra \documentclass[12pt]{minimal}\begin{document}${\cal A}_{\kappa }(2)$\end{document}Aκ(2) which provides a unified scheme for dealing with su3 (for κ < 0), su2, 1 (for κ > 0), and h4⊗h4 (for κ = 0) symmetries. Finite- and infinite-dimensional representations of \documentclass[12pt]{minimal}\begin{document}${\cal A}_{\kappa }(2)$\end{document}Aκ(2) are constructed for κ < 0 and κ ⩾ 0, respectively. Phase operators associated with \documentclass[12pt]{minimal}\begin{document}${\cal A}_{\kappa }(2)$\end{document}Aκ(2) are defined and temporally stable phase states (as well as vector phase states) are constructed as eigenstates of these operators. Finally, we discuss a relation between quantized phase states and a quadratic discrete Fourier transform and show how to use these states for constructing mutually unbiased bases.
Backward growth of plasma induced by long nanosecond laser pulse ablation
Authors: Zhou Yun , Tao Sha , Wu Benxin
Published: August 2011

An interesting physical phenomenon of laser-induced plasma backward growth has been found for long nanosecond (ns) laser pulse ablation, which has been rarely reported. Time-resolved observation shows that the plasma bottom appears to be detached from the ablated target surface shortly after laser pulse ends, and then the bottom grows backwards towards the target. This phenomenon is understood through an experimentally verified, physics-based model. The study shows that the plasma backward growth is fundamentally the backward growth of high-temperature region bottom boundary without any significant backward motion of material, and the underlying gas dynamic process has also been revealed.
Conductance switching in organic ferroelectric field-effect transistors
Authors: Asadi Kamal , Blom Paul W. M. , de Leeuw Dago M.
Published: August 2011

Staggered bottom-contact top-gate organic ferroelectric field-effect transistors are fabricated with poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) as ferroelectric gate and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] as semiconductor. Polarization reversal of the ferroelectric gate is monitored by displacement transients in the gate current. By varying both the source and drain biases and by using fully and partially polarized transistors, we show that conductance switching only requires polarization of P(VDF-TrFE) at the source electrode. Polarization at the drain is irrelevant and does not impede charge extraction.
Hierarchical structure and dynamics of an ionic liquid 1-octyl-3-methylimidazolium chloride
Authors: Yamamuro Osamu , Yamada Takeshi , Kofu Maiko , Nakakoshi Masamichi , Nagao Michihiro
Published: August 2011

We have performed the heat capacity, neutron diffraction, and neutron quasielastic scattering measurements of an ionic liquid 1-octyl-3-methylimidazolium chloride (C8mimCl). The heat capacity data revealed that C8mimCl exhibits a glass transition with a large heat capacity jump at Tg = 214 K, which is lower than Tg of C4mimCl with a shorter alkyl-chain. In the neutron diffraction measurement for a deuterated analogue, d-C8mimCl, the peaks associated with the inter-domain, inter-ionic, and inter-alkyl-chain correlations appeared at (3, 11, and 14) nm−1, respectively. The temperature dependence of these peaks indicates that the packing of the alkyl-chains becomes more compact and the domains become more vivid and larger as decreasing temperature. The quasielastic neutron scattering measurements using neutron spin echo and time-of-flight type instruments demonstrated that C8mimCl has faster relaxations probably owing to the alkyl-group and a slower relaxation owing to the ions. The latter relaxation, which is related to the glass transition, is of non-exponential as in the α relaxation of glass-forming molecular liquids. The relaxation of domains could not be observed in the present experiment but should have relaxation times longer than 100 ns. This is the first report to clarify temperature dependence of the hierarchical structure and relaxations simultaneously for a typical ionic liquid.
Spin exchange interactions in hexagonal manganites RMnO3 (R = Tb, Dy, Ho, Er) epitaxial thin films
Authors: Chen Xiang-Bai , Thi Minh Hien Nguyen , Lee D. , Jang S.-Y. , Noh T. W. , Yang In-Sang
Published: August 2011

We present the results of an optical method of quantitatively estimating the spin exchange interactions in hexagonal manganites RMnO3 (R = Tb, Dy, Ho, Er) epitaxial thin films. The two in-plane (a-b plane) spin exchange integrals J1 (intratrimer Mn-Mn interaction) and J2 (intertrimer Mn-Mn interaction) are deduced from the magnon scattering peak wavenumbers. We found that J2 decreases systematically when the R ionic radius increases, while J1 is nearly independent of R ionic radius, contrary to the expectation in single crystals. We show that the R dependence of J1 could be understood in terms of the stress in the thin films. Our result indicates that the stress has stronger effect on the atomic displacement of the intratrimer Mn-Mn distance than the intertrimer Mn-Mn distance.
Origin of the high p-doping in F intercalated graphene on SiC
Authors: Cheng Y. C. , Kaloni T. P. , Huang G. S. , Schwingenschlögl U.
Published: August 2011

The atomic and electronic structures of F intercalated epitaxial graphene on a SiC(0001) substrate are studied by first-principles calculations. A three-step fluorination process is proposed. First, F atoms are intercalated between the graphene and the SiC, which restores the Dirac point in the band structure. Second, saturation of the topmost Si dangling bonds introduces p-doping up to 0.37 eV. Third, F atoms bond covalently to the graphene to enhance the p-doping. Our model explains the highly p-doped state of graphene on SiC after fluorination [A. L. Walter et al., Appl. Phys. Lett. 98, 184102 (2011)].
Tunable temperature dependence of electrocaloric effect in ferroelectric relaxor poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene terpolymer
Authors: Li Xinyu , Qian Xiao-shi , Lu S. G. , Cheng Jiping , Fang Zhao , Zhang Q. M.
Published: August 2011

The electrocaloric effect (ECE) was directly measured in a relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) terpolymer. It was observed that the temperature dependence of ECE of the terpolymer films depends critically on the film preparation conditions. While the uniaxially stretched terpolymer films show pronounced temperature dependence of ECE, the non-stretched films exhibit nearly temperature independent ECE from 5 °C to 45 °C. Such a difference is likely caused by the changes in possible polar states and polar-correlation range by film stretching. Besides, large ECE (T > 15 °C) can be induced in both films at 30 °C and 150 MV/m.
Self-assembled Si/SiO2 superlattice in Si-rich oxide films
Authors: Hsiao Chu-Yun , Shih Chuan-Feng , Su Kuan-Wei , Chen Hui-Ju , Fu Sheng-Wen
Published: August 2011

This work involves as-prepared SiOx (x≤2) films that were deposited by reactive sputtering. The regular Si/SiO2 superlattices were self-assembled without post-annealing. The periodicity of Si/SiO2 superlattices was modulated by varying the oxygen flow rate and was associated with x in SiOx in the range 2–1.3. Si/SiO2 superlattices were formed under compressive stress and the factors that governed the periodicity were discussed.