bluuebunny/crossref_metadata_2025 huggingface dataset:
Microembolic signals measured by transcranial Doppler during transcatheter closure of atrial septal defect using the Amplatzer septal occluder
Authors: Itoh Shinich , Suda Kenji , Kishimoto Shintaro , Nishino Hiroshi , Kudo Yoshiyuki , Iemura Motofumi , Teramachi Yozo , Matsuishi Toyojiro , Yasunaga Hiroshi
Published: January 2011

Purpose

To determine the frequency and factors associated with increase in microembolic signals during transcatheter closure of atrial septal defect using the Amplatzer septal occluder.

Methods

During the procedure in 16 patients, we measured microembolic signals using transcranial Doppler. Procedure time was divided into five periods: right cardiac catheterisation; left cardiac catheterisation; left cardiac angiocardiography; sizing and long sheath placement; device placement and release. We compared numbers of microembolic signals among the five periods and identified factors associated with them.

Results

Mean size of septal occluder was 16 millimetres in diameter. Total number of microembolic signals was a median of 31.5, ranging from 3 to 113. Microembolic signals in three periods, left cardiac catheterisation; sizing, and long sheath placement; and device placement and release, were not significantly different from one another, but were significantly higher than those in the remaining two periods, right cardiac catheterisation and left cardiac angiocardiography (median was 9 in left cardiac catheterisation; 6 in sizing and long sheath placement; 6.5 in device placement and release, versus 0 in right cardiac catheterisation and 1 in left cardiac angiocardiography, p less than 0.05, respectively). Importantly, the time for device manipulation positively correlated with total number of microembolic signals (r equals 0.77, p less than 0.001), although fluoroscopic time, age, or size of septal occluder did not.

Conclusions

Transcatheter closure of atrial septal defect using the Amplatzer septal occluder produces microemboli, especially during device placement. To minimise the risk of systemic embolism, we must decrease the time for device manipulation.
Early diagnosis and screening of congenital cardiac anomalies
Authors: Dastgiri Saeed , Taghizadeh Mahdieh , Heidarzadeh Mohammad
Published: January 2011

Considerable numbers of congenital cardiac anomalies are missed at the time of delivery. Study reports show that congenital cardiac anomalies are the second most common birth defect in many countries. Despite this fact, our previous study showed that the prevalence of congenital cardiac anomalies is the fifth most common one, indicating that many of these defects might not be properly diagnosed at the time of delivery and birth. The aim of this study was to estimate the missing frequency of congenital cardiac anomalies at the time of delivery and birth. The population of the study was 185,650 births in the Northwest region of Iran covered by the Tabriz Registry of Congenital Anomalies. A total of 451 children with congenital cardiac anomalies were studied in the region from 2000 to 2009. The expected prevalence of congenital cardiac anomalies at birth was estimated to be 24.2 per 10,000 births while a prevalence of 9.2 per 10,000 births was observed at the same time and place. This indicated that 59.1% of children with congenital cardiac anomalies were not identified at birth (p-value less than 0.05). This proportion increased by 13% over the study period from 2000 to 2009 (p-value greater than 0.1). Our findings indicated that a remarkable frequency of congenital cardiac anomalies was not diagnosed at birth because there was no paediatric cardiologist available at the time of birth in the gynaecology and obstetrics wards.
Heritability of Response Inhibition in Children
Authors: Schachar Russell J. , Forget-Dubois Nadine , Dionne Ginette , Boivin Michel , Robaey Philippe
Published: January 2011

We report the heritability of response inhibition, latency, and variability, which are potential markers of genetic risk in neuropsychiatric conditions. Genetic and environmental influences on cancellation and restraint, response latency, and variability measured in a novel variant of the stop signal task were studied in 139 eight-year-old twin pairs from a birth cohort. Cancellation (50%), restraint (27%), and response latency (41%) showed significant heritability, the balance being non-shared environmental influences and/or error. Response variability was not heritable, with 23% of the variance attributable to shared environmental influences and 77% to non-shared environmental risk or error. The phenotypic correlation between response cancellation and restraint was −.44 and between response latency and restraint was .21. These phenotypic correlations were entirely genetic in origin. The phenotypic correlation between response variability and % successful inhibition was .27, but was not genetic. Cancellation and restraint were heritable and shared genetic influences, indicating that they may be influenced by a common gene or genes. Response latency was moderately heritable and shared genetic influences with restraint, but was not correlated with cancellation. Response variability was not heritable. These results support the potential of response inhibition and latency as endophenotypes in genetic research. (JINS, 2011,17, 238–247)
ON THE THREAT OF COUNTERFEITING
Authors: Li Yiting , Rocheteau Guillaume
Published: January 2011

We study counterfeiting of currency in a search-theoretic model of monetary exchange. In contrast to Nosal and Wallace [Journal of Monetary Economics 54, 229–246 (2007)], we establish that counterfeiting does not pose a threat to the existence of a monetary equilibrium; i.e., a monetary equilibrium exists irrespective of the cost of producing counterfeits, or the ease with which genuine money can be authenticated. However, the possibility of counterfeiting fiat money can affect its value, velocity, output, and welfare, even if no counterfeiting occurs in equilibrium. We provide two extensions of the model under which the threat of counterfeiting can materialize: counterfeits can circulate across periods, and sellers set terms of trade in some matches. Policies that make the currency more costly to counterfeit or easier to recognize raise the value of money and society's welfare, but the latter policy does not always decrease counterfeiting.
Effectiveness of the nutritional supplement used in the Mexican Oportunidades programme on growth, anaemia, morbidity and cognitive development in children aged 12–24 months
Authors: Rosado Jorge L , López Patricia , García Olga P , Alatorre Javier , Alvarado Claudia
Published: January 2011

Objective

To determine the effectiveness of the nutritional supplement developed for the Oportunidades programme on growth, prevalence of anaemia, morbidity and cognitive function of pre-school children.

Design

In a randomised, placebo-controlled longitudinal trial, children were assigned to one of three experimental treatment groups: Oportunidades food supplement (OFS), powdered milk (PM) and placebo (PL). Treatments were administered daily for 6 months. Weight, height and Hb were measured in all participants before and after supplementation. Morbidity was assessed two times per week for 6 months using validated questionnaires. The Bayley Scale of Infant Development Test was administered at baseline and after 6 months.

Setting

Three marginal rural communities of the state of Queretaro, Mexico.

Subjects

A total of 224 children, mean age 22·4 (sd 5·9) months, were recruited. After the 6-month intervention, 186 completed the study.

Results

No differences were found in the adjusted changes of weight, height or anaemia between treatment groups and PL. No differences were found in the number of episodes of gastrointestinal or respiratory disease, nor were there any differences in cognitive performance between treatment and PL groups after 6 months of supplementation.

Conclusions

Daily supplementation of 12–24-month-old children with OFS has no additional benefits in growth, anaemia, morbidity or cognitive performance.
Soda intake and osteoporosis risk in postmenopausal American-Indian women
Authors: Supplee Joy D , Duncan Glen E , Bruemmer Barbara , Goldberg Jack , Wen Yang , Henderson Jeffrey A
Published: January 2011

Objective

Low bone mass often leads to osteoporosis and increased risk of bone fractures. Soda consumption may contribute to imbalances that lead to decreased bone mineral density (BMD) and general bone health. We examined the relationship between soda consumption and osteoporosis risk in postmenopausal American-Indian women, an at-risk population because of nutritional and other lifestyle-related factors.

Design

Cross-sectional analysis using logistic regression to examine associations between soda consumption and osteoporosis, and linear regression to examine the association between soda consumption and BMD, with and without adjustment for demographic and lifestyle factors. Quantitative ultrasound of the heel was performed to estimate BMD (g/cm2).

Setting

American-Indian communities in the Northern Plains and Southwestern USA.

Subjects

A total of 438 postmenopausal American-Indian women.

Results

Women with osteoporosis were significantly older and had lower BMI, average daily soda intakes, BMD levels and use of hormones than women without osteoporosis (P< 0·05). Soda consumption was not associated with increased odds of osteoporosis in either unadjusted or adjusted models (P> 0·05), although age (increased), BMI (decreased) and past hormone use (decreased) were all significantly associated with osteoporosis risk (P< 0·05).

Conclusions

Although the present study did not find associations between soda consumption and osteoporosis risk in postmenopausal American-Indian women, analyses did confirm confounding between soda consumption and age and BMI. This suggests that any potential effects of soda consumption on bone health are largely mediated through these factors.
‘We're not told why – we're just told’: qualitative reflections about the Western Australian Go for 2&5® fruit and vegetable campaign
Authors: Carter Owen BJ , Pollard Christina M , Atkins Jenny FP , Marie Milliner Jessica , Pratt Iain S
Published: January 2011

Objective

To explore why there is a lack of acceptance among Western Australian (WA) adults of the Go for 2&5®fruit and vegetable social marketing message to consume at least five servings of vegetables per day.

Design

A series of focus group discussions comprised of homogeneous groups varied by sex and age, until saturation of themes was achieved, followed by thematic analysis.

Setting

Part of qualitative research for the Go for 2&5® fruit and vegetable social marketing campaign in WA (2009 population: 2·2 million).

Subjects

WA adults stratified by sex and age groups (18–29 and 30–55 years) drawn from the second and third quartiles of socio-economic disadvantage.

Results

Familiarity with the Go for 2&5® message was excellent. Understanding of what constitutes ‘two servings of fruit’ was excellent and regarded by participants as highly achievable. Understanding of what constitutes ‘five servings of vegetables’ was suboptimal with widespread overestimation contributing to the belief that it is unrealistic. Participants did not know how the 2&5 recommendation was formulated and believed that daily consumption of two servings of fruit and five of vegetables would confer no greater health benefit than one of fruit and three of vegetables. Participants assumed that the 2&5 recommendation was ‘aspirational’ in the sense that it was purposely exaggerated to simply encourage greater overall consumption.

Conclusions

A convincing case needs to be presented to WA adults as to why they should consume five servings of vegetables per day. Continuing efforts to educate incorporating what constitutes a serving will assist perceptions that the recommendation is realistic.
Comparison of modifiable health behaviours between persons with and without cancer: the Multiethnic Cohort
Authors: Ollberding Nicholas J , Maskarinec Gertraud , Wilkens Lynne R , Henderson Brian E , Kolonel Laurence N
Published: January 2011

Objective

To compare the prevalence of modifiable risk factors for cancer and other chronic diseases between adult cancer survivors and persons with no history of cancer.

Design

Cross-sectional.

Setting

Population-based sample residing in California and Hawaii.

Subjects

A total of 177 003 men and women aged 45–75 years who participated in the Multiethnic Cohort Study (MEC). Logistic regression was used to examine adherence to recommendations regarding modifiable risk factors among cancer survivors (n16 346) when compared with cohort members with no history of cancer (n160 657).

Results

Cancer survivors were less likely than cohort members with no history of cancer to meet recommendations specified in the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) 2007 report (OR = 0·97; 95 % CI 0·96, 0·99). No difference between groups was seen for adherence to dietary recommendations alone (OR = 0·99; 95 % CI 0·98, 1·01). Site-specific analyses showed that results for colorectal cancer were similar to those for all cancers combined, but survivors of breast (OR = 1·04; 95 % CI 1·02, 1·07) and prostate (OR = 1·04; 95 % CI 1·01, 1·07) cancer were more likely to meet dietary recommendations. Latino survivors were less likely to adhere to WCRF/AICR recommendations than Latino controls; however, differences across ethnic groups were not significant (Pinteraction= 0·64).

Conclusions

The modest differences found between adult cancer survivors and persons with no history of cancer suggest that a diagnosis of cancer in itself may not be associated with improvements in health behaviours related to cancer and other chronic diseases.
ARGUMENT IN MIXED COMPANY: MOM'S MAXIM VS. MILL'S PRINCIPLE
Authors: Aikin Scott , Talisse Robert
Published: January 2011

It is impolite to discuss matters of religion or politics in mixed company. So goes the popular adage which all of us were supposed to have learned as children from our mothers. Let's call it Mom's Maxim. We tend to accept Mom's Maxim. But is it philosophically sound? In this short essay, we raise some objections to Mom's Maxim and make a case for an alternative which we call Mill's Principle.
Large genetic variation for heat tolerance in the reference collection of chickpea ( Cicer arietinum L.) germplasm
Authors: Krishnamurthy L. , Gaur P. M. , Basu P. S. , Chaturvedi S. K. , Tripathi S. , Vadez V. , Rathore A. , Varshney R. K. , Gowda C. L. L.
Published: January 2011

Chickpea is the third most important pulse crop worldwide. Changes in cropping system that necessitate late planting, scope for expansion in rice fallows and the global warming are pushing chickpeas to relatively warmer growing environment. Such changes demand identification of varieties resilient to warmer temperature. Therefore, the reference collection of chickpea germplasm, defined based on molecular characterization of global composite collection, was screened for high temperature tolerance at two locations in India (Patancheru and Kanpur) by delayed sowing and synchronizing the reproductive phase of the crop with the occurrence of higher temperatures ( ≥ 35°C). A heat tolerance index (HTI) was calculated using a multiple regression approach where grain yield under heat stress is considered as a function of yield potential and time to 50% flowering. There were large and significant variations for HTI, phenology, yield and yield components at both the locations. There were highly significant genotypic effects and equally significant G × E interactions for all the traits studied. A cluster analysis of the HTI of the two locations yielded five cluster groups as stable tolerant (n = 18), tolerant only at Patancheru (n = 34), tolerant only at Kanpur (n = 23), moderately tolerant (n = 120) and stable sensitive (n = 82). The pod number per plant and the harvest index explained ≥ 60% of the variation in seed yield and ≥ 49% of HTI at Kanpur and ≥ 80% of the seed yield and ≥ 35% of HTI at Patancheru, indicating that partitioning as a consequence of poor pod set is the most affected trait under heat stress. A large number of heat-tolerant genotypes also happened to be drought tolerant.
THE PERMEABILITY OF RACIAL ATTITUDES IN THE AGE OF OBAMA
Authors: Kaufmann Karen M.
Published: January 2011

During the historic 2008 election, media pundits from far and wide proclaimed that Barack Obama was coming to power in a new post-racial era. The most enduring divide in American politics had apparently become passé, and the racial cleavages that have defined the social, economic, and political landscape since the country's founding somehow had become transformed. The actual election results did little to support this point of view, however. Approximately ninety-five percent of Black Americans supported Obama, as did approximately two-thirds of Latinos and Asian Americans. White Americans did not reject Obama out of hand, with forty-three percent supporting him, but race was not inconsequential to the vote (Pasek et al., 2009). Race clearly mattered in 2008, as it does now.
‘OBAMA STUDIES’ IN ITS INFANCY
Authors: Jeffries Michael P.
Published: January 2011

At the conclusion of Barack Obama's State of the Union address on January 27, 2010, MSNBC anchor Chris Matthews lavished praise on the president, infamously gushing, “It's interesting: he is post-racial, by appearances. I forgot he was Black tonight for an hour.” According to many, this is the greatest of all Obama's super-powers; the ability to sweet-talk the public into a euphoric political hallucination, transporting followers into a world where he is cleansed of the stain of Blackness and the citizenry lives in racial harmony. If this is true, White voters, including Matthews, forgot Obama was Black long before the State the Union. By many accounts, this post-racial amnesia, rather than the nuts and bolts of voter mobilization, fundraising, message-crafting, or opponents' mistakes, ultimately resulted in Obama's victory in the 2008 election.
WEALTH IN THE EXTENDED FAMILY
Authors: Chiteji Ngina S.
Published: January 2011

This paper argues that researchers may be misgauging family resources by focusing narrowly on the nuclear family when measuring these resources. While social scientists have long been interested in the ways that families' material resources affect their ability to provide for their offspring, the traditional measures of family resources have emphasized parents' income and parents' wealth, although the interest in the latter is relatively new (Conley 2009 [1999]; Haveman et al., 2001; Oliver and Shapiro, 2006 [1995]). This paper attempts to shift the focus to the extended family, and it uses data from the Panel Study of Income Dynamics (PSID) and the Child Development Supplement (CDS) to paint a portrait of the volume of wealth that is available in the grandparent generation of a child's family tree. After theorizing about the potential ways that grandparent wealth can affect children's life chances, the research shows that there are substantial differences in extended-family wealth by race. The Black/White wealth ratio is on the order of 0.11 in the grandparent generation at the median, which indicates that the typical Black child has grandparents with only about eleven cents of wealth for every dollar that the grandparents of the typical White child possess. Some implications of this wealth gap for children and society are discussed.
Nutritive value of bamboo as browse for livestock
Authors: Halvorson J.J. , Cassida K.A. , Turner K.E. , Belesky D.P.
Published: January 2011

Small farms in Appalachia need management options that diversify income opportunities, are adaptable to new livestock management strategies, and help maintain environmental integrity. Plantings of temperate bamboo (Poaceae), including species native to West Virginia, were established to determine the potential nutritive value for small ruminants, such as goats (Capra hircus), at different times of the year. The bamboo species we evaluated, included severalPhyllostachysspp.,Semiarundiaria fastuosaandArundinaria gigantea, were able to withstand Appalachian winter temperatures and retain some green leaves even in late winter. Although small differences were evident, the nutritive value was generally comparable among species and exhibited similar trends over the season. Total non-structural carbohydrates in bamboo leaves decreased throughout the growing season, and then remained stable or increased during winter. Conversely, crude protein was relatively low in young leaves compared to late season or over-wintered leaves. Concentrations of fiber and protein were sufficient to meet the maintenance needs of adult goats. The ability of bamboo to remain green and maintain the nutritive value throughout winter suggested that it has potential as winter forage for goats in central Appalachia. As an upright browse, bamboo may reduce the exposure of goats to gastrointestinal parasites. Perennial stands of temperate bamboo could prove to be a valuable, multiple-use crop suitable for Appalachian farm operations and easily adaptable to goat production systems.
Stability of NSLS-II girder–magnet assembly
Authors: Ravindranath V. , Sharma S. , Doom L. , Channing C. , Lincoln F. , Jain A. , Joshi P.
Published: January 2011

The low-emittance design of the NSLS-II (a new state-of-the-art medium energy third-generation storage ring) requires that the uncorrelated vertical RMS motion between the multipole magnets on a girder be less than 25 nm. The stability of the girder–magnet assembly is affected by factors such as ambient vibration, temperature fluctuations and diurnal floor motion in the storage ring. In this paper we discuss the design features of a high-stability girder–magnet assembly for the NSLS-II.
Fabrication of one-cell vacuum system for Taiwan Photon Source
Authors: Chen C. L. , Chang C. C. , Chan C. K. , Cheng C. M. , Yang C. Y. , Wu L. H. , Hsueh H. P. , Kuan C. K. , Syu J. C. , Hsiung G. Y. , Chen J. R.
Published: January 2011

A vacuum system of 3 GeV Taiwan photon source (TPS, with circumference 518.4 m), is designed for low-outgassing aluminium beam ducts, low-impedance structure, oil-less pumping system and oil-less fabrication. A prototype (total length 14 m) of the TPS vacuum system has been fabricated. This one-cell prototype vacuum system consists of two bending-magnet chambers (~4 m long each), two straight chambers (~3 m long each), supporting stands, five beam positioning monitors and pumps. Two bending-magnet chambers were made by computer-numerical control machining, which was lubricated with ethanol to protect the surface from oil contamination. Next, these two bending chambers were cleaned with ozonated water to decrease the rate of thermal outgassing and photo-stimulated desorption. The rest chambers were also cleaned by chemical cleaning method. An automatic welding system then was used to implement the side-welding seams of bending chambers in a temperature- and humidity-controlled cleanroom. The bending and straight chambers were welded into one piece by ‘on-site welding’. After baking at 150°C for 24 h, an optimizing pressure could be achieved at 4.9 nPa.
Evolution und Diversität von HIV-1
Authors: Metzner
Published: January 2011

Das humane Immundefizienzvirus Typ 1 (HIV-1) ist die Ursache einer Pandemie verheerenden Ausmasses. Die HIV-1-Infektion führt unbehandelt nach einer klinischen Latenzphase von mehreren Jahren zu der Erkrankung AIDS (acquired immunodeficiency syndrome) und dem damit verbundenen Auftreten opportunistischer Infektionen. Das Immunsystem des Patienten ist nicht in der Lage, das Virus effizient zu kontrollieren, geschweige denn, es zu eliminieren. Die antiretrovirale Therapie ist inzwischen sehr effizient, dennoch ist eine Heilung bislang nicht erreicht worden. Auch all die zahllosen Bemühungen zur Entwicklung eines Impfstoffes waren bislang erfolglos. Eine gemeinsame Ursache für Resistenzentwicklung unter Therapie sowie der Fehlbarkeiten des Immunsystems und der Impfstoffkandidaten ist die schnelle Anpassungsfähigkeit von HIV-1 und die damit verbundene hohe Diversität zirkulierender Virusvarianten weltweit und innerhalb eines jeden Patienten.
Toll-like receptors 2 and 4 in ischemic stroke: Outcome and therapeutic values
Authors: Brea David , Blanco Miguel , Ramos-Cabrer Pedro , Moldes Octavio , Arias Susana , Pérez-Mato María , Leira Rogelio , Sobrino Tomás , Castillo José
Published: January 2011

Stroke triggers an intense inflammatory response that could be a consequence of Toll-like receptors (TLRs) activation. However, the clinical significance and the therapeutic possibilities of TLR in stroke is not completely clear. In this study, we analyze the association between the expression of TLR2 and TLR4, inflammatory molecules and endogenous ligands, and clinical outcome of ischemic stroke patients, and we test the potential of TLR2/TLR4 and their endogenous ligands as therapeutic targets. For this purpose, we included 110 patients with ischemic stroke finding that TLR2 and TLR4 are independently associated to poor outcome and correlated with higher serum levels of interleukin (IL)1β, IL6, tumor necrosis factor α, and VCAM1, and that TLR4 was independently associated to lesion volume. In addition, we have developed an in vitro model to test the potential therapeutic value of blocking TLR2/TLR4 or their endogenous ligands. Cultured cells (monocytes and human umbilical vein endothelial cells) were treated with serum from ischemic stroke patients, showing a strong inflammatory response that was blocked when TLR2/4 or cellular fibronectin (cFN) or HSP60 were blocked. In conclusion, TLR2 and TLR4 are associated to outcome in stroke patients and TLR2/4 or their endogenous ligands, cFN/HSP60 could be new therapeutic targets for ischemic stroke.
Applying of novel subtraction method Genetically Directed Differential Subtraction Chain (GDDSC) in plant genomes
Authors: Siedlecka Ewa , Hromada-Judycka Aneta , Pawełkowicz Magdalena , Wóycicki Rafał , Rakoczy-Trojanowska Monika , Przybecki Zbigniew
Published: January 2011

We present a simple subtraction procedure of GDDSC as a modification of the original DSC and GDRDA methods. Genetically Directed Differential Subtraction Chain (GDDSC) is a process by which highly related genomes are compared in order to isolate tags carrying the polymorphisms.To detect specific DNA fragment (tag), we can then monitor offspring plants for efficient molecular breeding. The GDDSC protocol was applied to isolation of new sex related clones from cucumber plants (Cucumissativus L.) and new tissue culture response clones from rye (Secalecereale L.). The newly identified tags, obtained by GDDSC represent pools of candidate genes and other sequences, which could serve as potential markers for requested traits.
The elastic-plastic response of aluminum films to ultrafast laser-generated shocks
Authors: Whitley V. H. , McGrane S. D. , Eakins D. E. , Bolme C. A. , Moore D. S. , Bingert J. F.
Published: January 2011

We present the free surface response of 2, 5, and 8 μm aluminum films to shocks generated from chirped ultrafast lasers. We find two distinct steps to the measured free surface velocity that indicate a separation of the faster elastic wave from the slower plastic wave. We resolve the separation of the two waves to times as short as 20 ps. We measured peak elastic free surface velocities as high as 1.4 km/s corresponding to elastic stresses of 12 GPa. The elastic waves rapidly decay with increasing sample thickness. The magnitude of both the elastic wave and the plastic wave and the temporal separation between them was strongly dependent on the incident laser drive energy.
Generalized CC-TDSCF and LCSA: The system-energy representation
Authors: López-López Sergio , Nest Mathias , Martinazzo Rocco
Published: January 2011

Typical (sub)system-bath quantum dynamical problems are often investigated by means of (approximate) reduced equations of motion. Wavepacket approaches to the dynamics of the whole system have gained momentum in recent years and there is hope that properly designed approximations to the wavefunction will allow one to correctly describe the subsystem evolution. The continuous-configuration time-dependent self-consistent field (CC-TDSCF) and local coherent-state approximation (LCSA) methods, for instance, use a simple Hartree product of bath single-particle-functions for each discrete variable representation (DVR) state introduced in the Hilbert space of the subsystem. Here we focus on the above two methods and replace the DVR states with the eigenstates of the subsystem Hamiltonian, i.e., we adopt an energy-local representation for the subsystem. We find that stable and semiquantitative results are obtained for a number of dissipative problems, at the same (small) computational cost of the original methods. Furthermore, we find that both methods give very similar results, thus suggesting that coherent-states are well suited to describe (local) bath states. As a whole, present results highlight the importance of the system basis-set in the selected-multiconfiguration expansion of the wavefunction. They suggest that accurate and yet computationally cheap methods may be simply obtained from CC-TDSCF/LCSA by letting the subsystem states be variationally optimized.
Peak temperatures from Raman Stokes/anti-Stokes ratios during laser heating by a Gaussian beam
Authors: Herman Irving P.
Published: January 2011

The rise in temperature induced by heating a surface with a cw Gaussian laser is analytically related to the Raman Stokes/anti-Stokes intensity ratio measured by the same laser to induce the heating, for an idealized, though often experimentally-relevant, set of conditions. For a range of conditions, the peak temperature rise is actually twice that determined from this ratio if one were to assume a spatially uniform temperature rise. This shows that care must be exercised in determining temperature from Stokes/anti-Stokes ratios.
Characterization of ferroelectric material properties of multifunctional lead zirconate titanate for energy harvesting sensor nodes
Authors: Marinkovic Bozidar , Kaya Tolga , Koser Hur
Published: January 2011

We propose a microsystem integration technique that is ideal for low-cost fabrication of vibration energy harvesting sensor nodes. Our approach exploits diverse uses of sol-gel deposited lead zirconate titanate, effectively combining fabrication of several microsystem components into a single process and significantly reducing manufacturing cost and time. Here, we measure and characterize thin film parameters—such as the piezoelectric coefficient e31 (−4.0 C/m2), the dielectric constant εr-eff (219 at 3.3 V), and the total switching polarization (2Pr;52 μC/cm2)—in order to verify this material’s potential for energy harvesting, energy storage, and nonvolatile memory applications simultaneously on the same device.
Photoluminescence and photostimulated luminescence of oxygen impurities in CsBr
Authors: Appleby G. A. , Zimmermann J. , Hesse S. , von Seggern H.
Published: January 2011

Oxygen impurities have been detected in undoped CsBr by photoluminescence (PL) spectroscopy and their contribution to photostimulated luminescence (PSL) properties of powdered CsBr is discussed. When excited at 200 nm, PL is observed from CsBr which consists of three separate emission peaks. The intrinsic luminescence of CsBr at 379 nm is accompanied by two emission peaks at 395 and 460 nm which arise from oxygen impurities, the latter of which is also PSL active following x-irradiation. Sintering of CsBr with the reducing agent NH4Br removes the oxygen impurities so that the 395 and 460 nm emissions are no longer detectable, and subsequently the PSL emission is significantly reduced. PSL storage time measurements of these materials show that oxygen impurities favorably increase both the PSL sensitivity and radiation induced charge-center stability in CsBr:Eu2+. The oxygen impurities and their associated luminescence properties can be reintroduced to the CsBr matrix with a controlled concentration by doping with CsOH and then subsequently sintering the resultant CsBr:OH− with NH4Br, which in this system reduces the OH− centers to O2−.
Structure, electrical properties, and depoling mechanism of BiScO3–PbTiO3–Pb(Zn1/3Nb2/3)O3 high-temperature piezoelectric ceramics
Authors: Yao Zhonghua , Liu Hanxing , Hao Hua , Cao Minghe
Published: January 2011

The structure, electrical properties, and depoling mechanism of the (0.95−x)BiScO3−xPbTiO3−0.05Pb(Zn1/3Nb2/3)O3 (BS-xPT-PZN, x=0.54–0.70) compositions close to the morphotropic phase boundary (MPB) have been systematically investigated as a function of PbTiO3 content (x). The phase approached from the rhombohedral toward the tetragonal phase when the PbTiO3 contents increased. The composition with high PT content exhibited normal ferroelectric behavior while it showed a diffused phase transition characteristic as PT decreased. In the vicinity of the MPB, the ceramics showed enhanced piezoelectric, electromechanical, and ferroelectric properties with piezoelectric constant d33=490 pC/N, planar electromechanical coupling factors kp=57.4%, remnant polarization Pr=40.1 μC/cm2, and coercive field Ec=28.5 kV/cm with a high transition temperature Tm∼417 °C, respectively. The thermal depoling experiments of the polarization for samples with different phase structures were investigated and the possible depoling mechanism was discussed.
Substrate orientation effects on the nucleation and growth of the Mn+1AXn phase Ti2AlC
Authors: Tucker Mark D. , Persson Per O. Å. , Guenette Mathew C. , Rosén Johanna , Bilek Marcela M. M. , McKenzie David R.
Published: January 2011

The Mn+1AXn (MAX) phases are ternary compounds comprising alternating layers of a transition metal carbide or nitride and a third “A-group” element. The effect of substrate orientation on the growth of Ti2AlC MAX phase films was investigated by studying pulsed cathodic arc deposited samples grown on sapphire cut along the (0001), (101¯0), and (11¯02) crystallographic planes. Characterization of these samples was by x-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. On the (101¯0) substrate, tilted (101¯8) growth of Ti2AlC was found, such that the TiC octahedra of the MAX phase structure have the same orientation as a spontaneously formed epitaxial TiC sublayer, preserving the typical TiC–Ti2AlC epitaxial relationship and confirming the importance of this relationship in determining MAX phase film orientation. An additional component of Ti2AlC with tilted fiber texture was observed in this sample; tilted fiber texture, or axiotaxy, has not previously been seen in MAX phase films.
Major deep levels with the same microstructures observed in n-type 4H–SiC and 6H–SiC
Authors: Sasaki S. , Kawahara K. , Feng G. , Alfieri G. , Kimoto T.
Published: January 2011

Major deep levels observed in as-grown and irradiated n-type 4H–SiC and 6H–SiC epilayers have been investigated. After low-energy electron irradiation, by which only carbon atoms are displaced, five traps, EH1 (EC−0.36 eV), Z1/Z2 (EC−0.65 eV), EH3 (EC−0.79 eV), EH5 (EC−1.0 eV), and EH6/7 (EC−1.48 eV), were detected in 4H–SiC and four traps, E1/E2 (EC−0.45 eV), RD5 (EC−0.57 eV), ES (EC−0.80 eV), and R (EC−1.25 eV), were detected in 6H–SiC. The Z1/Z2, EH6/7 centers in 4H–SiC and the E1/E2, R centers in 6H–SiC exhibit common features as follows: their generation rates by the e−-irradiation were almost the same each other, their concentrations were not changed by heat treatments up to 1500 °C, and they showed very similar annealing behaviors at elevated temperatures. Furthermore, these defect centers were almost eliminated by thermal oxidation. Taking account of the observed results and the energy positions, the authors suggest that the Z1/Z2 center in 4H–SiC corresponds to the E1/E2 center in 6H–SiC, and the EH6/7 center in 4H–SiC to the R center in 6H–SiC, respectively. Since the concentrations of these four centers are almost the same for as-grown, electron-irradiated, annealed, and oxidized samples, these centers will contain a common intrinsic defect, most likely carbon vacancy. The authors also observed similar correspondence for other thermally unstable traps in 4H–SiC and 6H–SiC.
Mirrorlike pulsed laser deposited tungsten thin film
Authors: Mostako A. T. T. , Rao C. V. S. , Khare Alika
Published: January 2011

Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10−5 Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ∼782 nm.
Contact resistivity and Fermi-level pinning in n-type Ge contacts with epitaxial Si-passivation
Authors: Martens Koen , Rooyackers R. , Firrincieli A. , Vincent B. , Loo R. , De Jaeger B. , Meuris M. , Favia P. , Bender H. , Douhard B. , Vandervorst W. , Simoen E. , Jurczak M. , Wouters D. J. , Kittl J. A.
Published: January 2011

We report on the study of the electrical and material properties of n-Ge contacts with a thin Si-passivation layer. n-Ge contacts typically show Fermi-level pinning and low dopant activation which results in too large specific contact resistivities of >10−4 Ω cm2 and which impedes applications such as high performance Ge complementary metal-oxide semiconductor technology. In this work a thin in situ doped (1×1020 cm−3 of phosphorus) epitaxial Si-passivation layer is grown selectively on n-Ge, followed by a Ti/TiN stack deposition. The insertion of this thin Si-passivation layer reduces the pinning and activation limitation, achieving specific contact resistivity values of ∼1×10−6 Ω cm2. Physical modeling of the specific contact resistivities was performed, providing the insight validating the underlying explanation of the improvement. Key factors for the contact resistivity lowering are the good alignment of the Si and Ge conduction bands and the higher doping concentration achieved in Si.
Thickness dependence of the effective damping in epitaxial Fe3O4/MgO thin films
Authors: Serrano-Guisan S. , Wu Han-Chun , Boothman C , Abid M. , Chun B. S. , Shvets I. V. , Schumacher H. W.
Published: January 2011

The precessional magnetization dynamics of high quality epitaxial magnetite (Fe3O4) thin films growth on MgO are investigated by inductive magnetization dynamic measurements in time and frequency domain. An upper bound for the intrinsic Gilbert damping parameter of α0=0.037±0.001 is derived, which is significantly lower than previously reported for epitaxial Fe3O4 on GaAs. With increasing film thickness from 5 up to 100 nm a strong increase in the effective damping up to 0.2 is observed which cannot be explained by simple nonuniform spin wave excitations. Possible origins of this effect are discussed.
Energy model and band-gap modulation of graphene band self-organized on the functional vicinal surfaces
Authors: Wan J. F. , Kong X. Y.
Published: January 2011

An energy model of graphene band self-organized on the vicinal surfaces was proposed to study its stabilization mechanism. Based on the energy minimum principle, an equilibrium width equation of graphene band was built to explain the crossing-step growth mode. The narrowest graphene band (1–5 nm) with a zigzag edge compared with armchair and other edges was predicted to be more stable on the vicinal surface (<5 nm). The regularly stepped surface could provide a promising platform to realize the band-gap modulation engineering by means of the quantitative relation between the band-gap of graphene and the step width for future nanodevices.
Effective work function lowering of multilayer graphene films by subnanometer thick AlOx overlayers
Authors: Yi Yeonjin , Choi Won Mook , Kim Yoon Hak , Won Kim Jeong , Kang Seong Jun
Published: January 2011

A simple method for controlling the effective work function (WF) of conductive multilayer graphene (MLG) film, synthesized by using chemical vapor deposition and transferred to a dielectric substrate, was developed. The WFs of the MLG during the step-by-step deposition of aluminum (Al) were measured using in situ ultraviolet photoelectron spectroscopy. Core-level spectra were also collected to investigate the chemical reaction that occurred when a small amount of Al was deposited onto MLG in a stepwise manner. The measurements revealed that the effective WF of the conductive MLG film could be controlled from 3.77 to 4.40 eV by the deposition of an Al layer less than 0.6 nm thick.
Efficient fluorescence emission and photon conversion of LaOF:Eu3+ nanocrystals
Authors: Gao Dangli , Zheng Hairong , Zhang Xiangyu , Fu Zhenxing , Zhang Zhenglong , Tian Yu , Cui Min
Published: January 2011

Efficient spectral conversion of 325–550 nm light to 570–710 nm light has been demonstrated in LaOF:Eu3+ nanocrystals. When levels above the D50 level of Eu3+ are optically excited, strong emission arising from the D50 level is obtained in the range of 570–710 nm, a highly efficient working range for organic solar cells. The influences of ambient temperature, particle size, dopant concentration, and codoped ions on the fluorescence intensity of Eu3+ are discussed in detail. The photon conversion efficiency can reach 3.91% in LaOF:Eu3+ codoped with Tm3+, if light reflection and scattering effects are ignored
Influence of threading dislocations on GaN-based metal-semiconductor-metal ultraviolet photodetectors
Authors: Li Dabing , Sun Xiaojuan , Song Hang , Li Zhiming , Chen Yiren , Miao Guoqing , Jiang Hong
Published: January 2011

The influence of threading dislocations on the properties of GaN-based metal-semiconductor-metal (MSM) ultraviolet photodetectors was investigated. It was found that screw dislocations had a strong influence on the dark current of the photodetectors, while edge dislocations had the predominant effect on their responsivity. The dark current increased as the screw dislocation density increased due to their lowering of the Schottky barrier height. However, the responsivity of the photodetectors decreased with increasing edge dislocation density because of the dangling bonds along those edge dislocation lines which enhance the recombination of photogenerated electron-hole pairs. The results suggest that reducing both the screw and edge dislocation densities is an effective way to improve the photoelectric property of GaN-based MSM ultraviolet photodetectors.
Polarized spontaneous emission from blue-green m-plane GaN-based light emitting diodes
Authors: Brinkley Stuart E. , Lin You-Da , Chakraborty Arpan , Pfaff Nathan , Cohen Daniel , Speck James S. , Nakamura Shuji , DenBaars Steven P.
Published: January 2011

The polarization of spontaneous emission was investigated for various indium compositions and quantum wells on m-plane oriented gallium nitride (GaN) light emitting diodes (LEDs) grown on bulk-GaN substrates. Internal light scattering and depolarization was mitigated with application of absorber materials to the LED die. The polarization ratio (ρ) was measured under electrical injection for devices with InGaN active regions emitting up to 520 nm and observed as high as 96%. Values of ρ were independent of drive current. The valence band energy separation (ΔE) was characterized using spectral measurement and temperature dependent optical analysis of valence band hole distributions.
Floral ontogeny in Wisteria sinensis (Fabaceae: Faboideae: Millettieae) and its systematic implications
Authors: Naghiloo Somayeh , Dadpour Mohammad Reza
Published: January 2011

Floral organogenesis and development of the bushy perennial legume Wisteria sinensis (Millettieae, Fabaceae) were studied by epi-illumination light-microscopy techniques. Zygomorphic flowers of W. sinensis were arranged in alternating pentamerous whorls. The order of organogenesis in each whorl was unidirectional, except for the outer antesepalous stamens, which were initiated bidirectionally, starting on the lateral side. Unusual developmental features for the family included the formation of common primordia, comprised of the petal and the corresponding abaxial antepetalous stamen and the temporal overlap of corolla, androecium and carpel organ initiation. Unusual features during late development included formation of nectar windows and a wet stigma. The floral ontogeny of W. sinensis was more similar to that of other genera from the inverted-repeat-lacking clade (IRLC) than to the floral ontogeny of other Millettieae that have been investigated.
A hyperactive
piggyBac
transposase for mammalian applications
Authors: Yusa Kosuke , Zhou Liqin , Li Meng Amy , Bradley Allan , Craig Nancy L.
Published: January 2011

DNA transposons have been widely used for transgenesis and insertional mutagenesis in various organisms. Among the transposons active in mammalian cells, the moth-derived transposon
piggyBac
is most promising with its highly efficient transposition, large cargo capacity, and precise repair of the donor site. Here we report the generation of a hyperactive
piggyBac
transposase. The active transposition of
piggyBac
in multiple organisms allowed us to screen a transposase mutant library in yeast for hyperactive mutants and then to test candidates in mouse ES cells. We isolated 18 hyperactive mutants in yeast, among which five were also hyperactive in mammalian cells. By combining all mutations, a total of 7 aa substitutions, into a single reading frame, we generated a unique hyperactive
piggyBac
transposase with 17-fold and ninefold increases in excision and integration, respectively. We showed its applicability by demonstrating an increased efficiency of generation of transgene-free mouse induced pluripotent stem cells. We also analyzed whether this hyperactive
piggyBac
transposase affects the genomic integrity of the host cells. The frequency of footprints left by the hyperactive
piggyBac
transposase was as low as WT transposase (~1%) and we found no evidence that the expression of the transposase affects genomic integrity. This hyperactive
piggyBac
transposase expands the utility of the
piggyBac
transposon for applications in mammalian genetics and gene therapy.
Copper resistance is essential for virulence of
Mycobacterium tuberculosis
Authors: Wolschendorf Frank , Ackart David , Shrestha Tej B. , Hascall-Dove Laurel , Nolan Scott , Lamichhane Gyanu , Wang Ying , Bossmann Stefan H. , Basaraba Randall J. , Niederweis Michael
Published: January 2011

Copper (Cu) is essential for many biological processes, but is toxic when present in excessive amounts. In this study, we provide evidence that Cu plays a crucial role in controlling tuberculosis. A
Mycobacterium tuberculosis
(
Mtb
) mutant lacking the outer membrane channel protein Rv1698 accumulated 100-fold more Cu and was more susceptible to Cu toxicity than WT
Mtb
. Similar phenotypes were observed for a
M. smegmatis
mutant lacking the homolog Ms3747, demonstrating that these mycobacterial copper transport proteins B (MctB) are essential for Cu resistance and maintenance of low intracellular Cu levels. Guinea pigs responded to infection with
Mtb
by increasing the Cu concentration in lung lesions. Loss of MctB resulted in a 1,000- and 100-fold reduced bacterial burden in lungs and lymph nodes, respectively, in guinea pigs infected with
Mtb
. In mice, the persistence defect of the
Mtb mctB
mutant was exacerbated by the addition of Cu to the diet. These experiments provide evidence that Cu is used by the mammalian host to control
Mtb
infection and that Cu resistance mechanisms are crucial for
Mtb
virulence. Importantly,
Mtb
is much more susceptible to Cu than other bacteria and is killed in vitro by Cu concentrations lower than those found in phagosomes of macrophages. Hence, this study reveals an Achilles heel of
Mtb
that might be a promising target for tuberculosis chemotherapy.