bluuebunny/crossref_metadata_2025 huggingface dataset:
Independent Emergence of Yersinia ruckeri Biotype 2 in the United States and Europe
Authors: Welch Timothy J. , Verner-Jeffreys David W. , Dalsgaard Inger , Wiklund Thomas , Evenhuis Jason P. , Garcia Cabrera Jose A. , Hinshaw Jeffrey M. , Drennan John D. , LaPatra Scott E.
Published: March 2011

Biotype 2 (BT2) variants of the bacterium
Yersinia ruckeri
are an increasing disease problem in U.S. and European aquaculture and have been characterized as serovar 1 isolates that lack both peritrichous flagella and secreted phospholipase activity. The emergence of this biotype has been associated with an increased frequency of enteric redmouth disease (ERM) outbreaks in previously vaccinated salmonid fish. In this study, four independent specific natural mutations that cause the loss of both motility and secreted lipase activity were identified in BT2 strains from the United States, United Kingdom, and mainland Europe. Each of these was a unique mutation in either
fliR
,
flhA
, or
flhB
, all of which are genes predicted to encode essential components of the flagellar secretion apparatus. Our results demonstrate the existence of independent mutations leading to the BT2 phenotype; thus, this phenotype has emerged separately at least four times. In addition, BT2 strains from the United Kingdom were shown to have the same mutant allele found in U.S. BT2 strains, suggesting a common origin of this BT2 lineage. This differentiation of distinct BT2 lineages is of critical importance for the development and validation of alternative vaccines or other treatment strategies intended for the control of BT2 strains.
Strain-Dependent Norovirus Bioaccumulation in Oysters
Authors: Maalouf Haifa , Schaeffer Julien , Parnaudeau Sylvain , Le Pendu Jacques , Atmar Robert L. , Crawford Sue E. , Le Guyader Françoise S.
Published: March 2011

Noroviruses (NoVs) are the main agents of gastroenteritis in humans and the primary pathogens of shellfish-related outbreaks. Some NoV strains bind to shellfish tissues by using carbohydrate structures similar to their human ligands, leading to the hypothesis that such ligands may influence bioaccumulation. This study compares the bioaccumulation efficiencies and tissue distributions in oysters (Crassostrea gigas) of three strains from the two principal human norovirus genogroups. Clear differences between strains were observed. The GI.1 strain was the most efficiently concentrated strain. Bioaccumulation specifically occurred in digestive tissues in a dose-dependent manner, and its efficiency paralleled ligand expression, which was highest during the cold months. In comparison, the GII.4 strain was very poorly bioaccumulated and was recovered in almost all tissues without seasonal influence. The GII.3 strain presented an intermediate behavior, without seasonal effect and with less bioaccumulation efficiency than that of the GI.1 strain during the cold months. In addition, the GII.3 strain was transiently concentrated in gills and mantle before being almost specifically accumulated in digestive tissues. Carbohydrate ligand specificities of the strains at least partly explain the strain-dependent bioaccumulation characteristics. In particular, binding to the digestive-tube-specific ligand should contribute to bioaccumulation, whereas we hypothesize that binding to the sialic acid-containing ligand present in all tissues would contribute to retain virus particles in the gills or mantle and lead to rapid destruction.
Uncovering a Role for the Tail of the Dictyostelium discoideum SadA Protein in Cell-Substrate Adhesion
Authors: Kowal Anthony S. , Chisholm Rex L.
Published: March 2011

Previous work from our laboratory showed that theDictyostelium discoideumSadA protein plays a central role in cell-substrate adhesion. SadA null cells exhibit a loss of adhesion, a disrupted actin cytoskeleton, and a cytokinesis defect. How SadA mediates these phenotypes is unknown. This work addresses the mechanism of SadA function, demonstrating an important role for the C-terminal cytoplasmic tail in SadA function. We found that a SadA tailless mutant was unable to rescue thesadAadhesion deficiency, and overexpression of the SadA tail domain reduced adhesion in wild-type cells. We also show that SadA is closely associated with the actin cytoskeleton. Mutagenesis studies suggested that four serine residues in the tail, S924/S925 and S940/S941, may regulate association of SadA with the actin cytoskeleton. GlutathioneS-transferase pull-down assays identified at least one likely interaction partner of the SadA tail, cortexillin I, a known actin bundling protein. Thus, our data demonstrate an important role for the carboxy-terminal cytoplasmic tail in SadA function and strongly suggest that a phosphorylation event in this tail regulates an interaction with cortexillin I. Based on our data, we propose a model for the function of SadA.
Mimicry of the Pathogenic Mycobacterium VacuoleIn VitroElicits the Bacterial Intracellular Phenotype, Including Early-Onset Macrophage Death
Authors: Early Julie , Bermudez Luiz E.
Published: March 2011

Mycobacterium aviumcomplex (MAC) within macrophages undergoes a phenotype change that allows for more efficient entry into surrounding host cells. We hypothesized that, by developing anin vitrosystem resembling the intravacuolar environment, one could generate insights into the mycobacterial intracellular phenotype. MAC was incubated in “elemental mixtures” that reproduce metal concentrations and pH in the vacuoles at different time points and then used to infect fresh macrophages. Incubation of MAC with the mixture corresponding to the vacuole environment 24 h postinfection infected macrophages at a significantly higher rate than bacteria that were incubated in Middlebrook 7H9 broth. Uptake occurred by macropinocytosis, similar to the uptake of bacteria passed through macrophages. Genes reported to be upregulated in intracellular bacteria, such asMav1365,Mav2409,Mav4487, andMav0996, were upregulated in MAC incubated in the 24-h elemental mixture. Like MAC obtained from macrophages, the vacuoles of bacteria from the 24-h elemental mixture were more likely to contain lysosome-associated membrane protein 1 (LAMP-1). A stepwise reduction scheme of the 24-h elemental mixture indicated that incubation in physiologically relevant concentrations of potassium chloride, calcium chloride, and manganese chloride was sufficient to induce characteristics of the intracellular phenotype. It was demonstrated that bacteria harboring the intracellular phenotype induced early-onset macrophage death more efficiently than bacteria grown in broth. This new trace elemental mixture mimicking the condition of the vacuole at different time points has the potential to become an effective laboratory tool for the study of the MAC andMycobacterium tuberculosisdisease process, increasing the understanding of the interaction with macrophages.
Molecular Basis of Immunity to Rickettsial Infection Conferred through Outer Membrane Protein B
Authors: Chan Yvonne Gar-Yun , Riley Sean Phillip , Chen Emily , Martinez Juan José
Published: March 2011

Pathogenic rickettsiae are the causative agents of Rocky Mountain spotted fever, typhus, and other human diseases with high mortality and an important impact on society. Although survivors of rickettsial infections are considered immune to disease, the molecular basis of this immunity or the identification of protective antigens that enable vaccine development was hitherto not known. By exploring the molecular pathogenesis ofRickettsia conorii, the agent of Mediterranean spotted fever, we report here that the autotransporter protein, rickettsial outer membrane protein B (rOmpB), constitutes a protective antigen for this group of pathogens. A recombinant, purified rOmpB passenger domain fragment comprised of amino acids 36 to 1334 is sufficient to elicit humoral immune responses that protect animals against lethal disease. Protective immunity requires folded antigen and production of antibodies that recognize conformational epitopes on the rickettsial surface. Monoclonal antibodies (MAbs) 5C7.27 and 5C7.31, which specifically recognize a conformation present in the folded, intact rOmpB passenger domain, are sufficient to confer immunityin vivo. Analysesin vitroindicate this protection involves a mechanism of complement-mediated killing in mammalian blood, a means of rickettsial clearance that has not been previously described. Considering the evolutionary conservation of rOmpB and its crucial contribution to bacterial invasion of host cells, we propose that rOmpB antibody-mediated killing confers immunity to rickettsial infection.
Genome Sequences of the High-Acetic Acid-Resistant Bacteria Gluconacetobacter europaeus LMG 18890
T
and G. europaeus LMG 18494 (Reference Strains), G. europaeus 5P3, and Gluconacetobacter oboediens 174Bp2 (Isolated from Vinegar)
Authors: Andrés-Barrao Cristina , Falquet Laurent , Calderon-Copete Sandra P. , Descombes Patrick , Ortega Pérez Ruben , Barja François
Published: March 2011

Bacteria of the genus
Gluconacetobacter
are usually involved in the industrial production of vinegars with high acetic acid concentrations. We describe here the genome sequence of three
Gluconacetobacter europaeus
strains, a very common bacterial species from industrial fermentors, as well as of a
Gluconacetobacter oboediens
strain.
Forbidden Points’ in Pregnancy: Historical Wisdom?
Authors: Betts Debra , Budd Sarah
Published: March 2011

Within the acupuncture literature there is debate on the safety of using specific acupuncture points during pregnancy. Termed ‘forbidden’ or contraindicated, they refer to acupuncture points that can be used to induce labour but may also include points with no known inducing or labour-enhancing effects. Recommendations range from avoiding these acupuncture points at any time in pregnancy to statements that despite the warnings in the literature, these points are not contraindicated during a normal pregnancy. This discussion paper examines the historical use of contraindicated points, the physiology of the pregnant body and the effect of these points during research trials. It is hoped that this will encourage further discussion and provide a background for practitioners to make informed choices about how they use these points in clinical practice.
Different approaches to obtaining consent for follow-up result in biased samples
Authors: Pless Barry , Hagel Brent , Zhang Xun , Magdalinos Helen
Published: March 2011

Background

Many injury studies use samples of hospital patients. If a study requires further contact, consent is usually required but the sample may be biased if many fail to consent.

Objective

To determine whether wording requiring ‘active’ consent resulted in more refusals than wording that was ‘passive’—that is, where consent is implied in the absence of direct refusal.

Methods

Subjects were injured children seen in the emergency departments in five hospitals where the Canadian Hospital Injury Reporting and Prevention Program (CHIRPP) operates. For CHIRPP, parents or older children complete a one-page questionnaire to describe the injury; one question seeks consent to follow-up for research. Three of the hospitals use passive wording for this question and two use active wording. All cases where CHIRPP coordinators completed forms using the medical record were treated as refusals. It was hypothesised that there would be a significant association between the form of wording (active or passive) and the rate of consent, and that this association would be affected by socio-demographic and clinical variables.

Results

On average, 64.5% of parents gave consent for follow-up at hospitals using passive consent wording versus 42% where active consent wording was used. Passive wording consistently yielded a higher percentage of consents for all variables. The differences were greater than 5% for families living in census tracts with low median household incomes and greater than 10% for those age 15–19 years. For parent completed forms the adjusted OR for active wording was 0.48 (95% CI 0.43 to 0.54).

Conclusion

Caution is needed when interpreting results from studies using hospital samples, especially when wording of consent for follow-up requires direct affirmation.
Are we homogenising risk factors for public health surveillance? Variability in severe injuries on First Nations reserves in British Columbia, 2001–5
Authors: Bell Nathaniel , Schuurman Nadine , Hameed S Morad , Caron Nadine
Published: March 2011

Background

Aboriginal Canadians are considered to be at increased risk of injury. The de facto standard for measuring injury risk factors among Aboriginal Canadians is to compare hospitalisation and mortality against non-Aboriginal Canadians, but this may be too broad an approach for injury prevention and public health if it over-generalises injury risk.

Methods

Data from this study are drawn from the 2001–5 British Columbia Trauma Registry and British Columbia Coroner's Service. Observed and expected hospitalisations and mortality rates on reserves were assessed against three different spatial aggregations of non-reserve reference populations. Data analysis was conducted in a geographical information system using a Poisson probability map.

Results

A total of 47 (9.6%) of 487 reserves in British Columbia contained at least one person who was hospitalised or died as a result of serious injury during the study period. Of these, two reserve populations represented 20% (n=19) of all injury morbidity events and 30% (n=22) of all mortality events.

Conclusion

Evidence from this study suggests that community-based rather than provincial-based injury reporting is less likely to over-generalise the burden of injury among Aboriginal communities. Community-based surveillance enables researchers to identify why severe unintentional and intentional injury continues to burden some communities but not others and avoids the potentially demoralising and stigmatising effects of current surveillance practices.
Predictive factors for ciclosporin-associated nephrotoxicity in children with minimal change nephrotic syndrome
Authors: Kim Ji Hong , Park Se Jin , Yoon So Jin , Lim Beom Jin , Jeong Hyeon Joo , Lee Jae Seung , Kim Pyung Kil , Shin Jae Il
Published: March 2011

Aims

To identify the predictive factors for ciclosporin A (CyA)-associated nephrotoxicity (CAN) in children with minimal change nephrotic syndrome (MCNS).

Methods

The clinical and laboratory findings of 58 children (median age 3.2 years, range 1.1–13.1 years, male:female 48:10) with MCNS who were treated with CyA from 1992 to 2002 were analysed retrospectively. Forty-eight (83%) of them were steroid dependent and 10 (17%) were steroid resistant. The starting dose of CyA was 5 mg/kg per day, and the desired drug level was kept at 100–200 ng/ml. Serial renal biopsies were performed before and after CyA therapy.

Results

Twenty-two patients (38%) had CAN (group I) and 36 (62%) did not (group II). There were no differences in the age at onset, sex, initial response to steroids, duration of CyA therapy and relapse rates. However, the median CyA trough levels were significantly higher in group I than in group II (218.0±15.2 vs 171.8±6.7 ng/ml, p=0.01). Changes in creatinine clearance were more decreased in group I than in group II (−39.4±8.2 vs 2.7±4.3 ml/min per 1.73 m2, p<0.0001). Multiple logistic regression analysis also revealed the median CyA trough level was an independent risk factor for the development of CAN (OR 1.025, 95% CI 1.007 to 1.044, p=0.007).

Conclusions

The median CyA trough level was an independent and significant risk factor for the development of CAN in children with MCNS receiving moderate-dose CyA.
Mast cell densities in bronchial biopsies and small airways are related
Authors: Carroll M L , Carroll N G , Gundersen H J , James A L
Published: March 2011

Introduction

The study sought to determine whether mast cell counts in endobronchial biopsies of large airways are related to mast cell counts in the small airways.

Methods

Lungs, obtained postmortem from 10 subjects who had died of non-respiratory causes, were fixed in inflation. Mast cell densities (cells/mm3), determined with an optical disector, were compared on histological sections (30 μm thick) of biopsies and small airways stained with human anti-mast cell tryptase.

Results

Mean mast cell density over the inner airway wall in biopsies was significantly related to mean mast cell density over the total airway wall in the small airways (r=∼0.80, p<0.01). A minimum of three biopsies per case was required to demonstrate this relationship. Within relevant count areas, mast cell density was about 1.6-fold higher in the small airways than in the biopsies.

Conclusions

These findings suggest that when mean counts from at least three biopsies per case are used, intersubject comparisons of mast cell density in the inner airway wall in endobronchial biopsies reflect intersubject comparisons of mast cell density over the total airway wall in small airways. This is despite the observation that mast cell densities are generally higher in the small airways.
Correlation between cerebral blood flow and oxygen saturation in patients with subarachnoid hemorrhage and traumatic brain injury
Authors: Shafer Robert , Brown Alice , Taylor Christopher
Published: March 2011

The INVOS cerebral oximeter and portable xenon enhanced CT (Xe/CT) scan are two commonly used diagnostic devices in patients who have experienced neurologic insults such as traumatic brain injury and subarachnoid hemorrhage. While the INVOS device is a relatively inexpensive, non-invasive measure of cerebral blood oxygen saturation, Xe/CT is a more complex costly diagnostic test that is the current gold standard for assessing cerebral perfusion in patients in the neurosciences intensive care unit (NSI) at the University of New Mexico Hospital. The purpose of this research was to investigate a possible relationship between these two diagnostic devices that might enable clinicians to better determine the appropriate timing and necessity of Xe/CT scans by evaluating trends in cerebral oximetry. The research was conducted in the University of New Mexico Hospital NSI over 18 months, with 25 imaging studies being collected from among 22 patients. Computer generated cortical segments obtained from the Xe/CT scans were correlated to INVOS cerebral oximeter pad placement on each patient's forehead, and the values were then compared using Spearman correlation coefficients. In this study, no statistically significant relationship between the devices was found although expansion of the study to a greater number of patients may uncover such a relationship.
The attribution of work environment in explaining gender differences in long-term sickness absence: results from the prospective DREAM study: Table 1
Authors: Labriola Merete , Holte Kari Anne , Christensen Karl Bang , Feveile Helene , Alexanderson Kristina , Lund Thomas
Published: March 2011

Objectives

To identify differences in risk of long-term sickness absence between female and male employees in Denmark and to examine to what extent differences could be explained by work environment factors.

Methods

A cohort of 5026 employees (49.1% women, mean age 40.4 years; 50.9% men, mean age 40.2 years) was interviewed in 2000 regarding gender, age, family status, socio-economic position and psychosocial and physical work environment factors. The participants were followed for 18 months in order to assess their incidence of long-term sickness absence exceeding 8 consecutive weeks.

Results

298 workers (5.9%) received sickness absence compensation for 8 weeks or more. Women had an excess risk of 37% compared to men, when adjusting for age, family status and socio-economic position. Physical work environment exposures could not explain this difference, whereas differences in psychosocial work environment exposures explained 32% of the differences in risk of long-term sickness absence between men and women, causing the effect of gender to become statistically insignificant. The combined effect of physical and psychosocial factors was similar, explaining 30% of the gender difference.

Conclusion

Differences in psychosocial work environments in terms of emotional demands, reward at work, management quality and role conflicts, explained roughly 30% of women's excess long-term sickness absence risk. Assuming women and men had identical working conditions would leave the larger part of the gender difference in long-term sickness absence from work unexplained.
Enhancement of systemic and sputum granulocyte response to inhaled endotoxin in people with the GSTM1 null genotype: Figure 1
Authors: Dillon Madeline A , Harris Bradford , Hernandez Michelle L , Zou Baiming , Reed William , Bromberg Philip A , Devlin Robert B , Diaz-Sanchez David , Kleeberger Steven , Zhou Haibo , Lay John C , Alexis Neil E , Peden David B
Published: March 2011

Objective

To determine if the GSTM1 null genotype is a risk factor for increased inflammatory response to inhaled endotoxin.

Methods

35 volunteers who had undergone inhalation challenge with a 20 000 endotoxin unit dose of Clinical Center Reference Endotoxin (CCRE) were genotyped for the GSTM1 null polymorphism. Parameters of airway and systemic inflammation observed before and after challenge were compared in GSTM1 null (n=17) and GSTM1 (n=18) sufficient volunteers.

Results

GSTM1 null volunteers had significantly increased circulating white blood cells (WBCs), polymorphonuclear neutrophils (PMNs), platelets and sputum PMNs (% sputum PMNs and PMNs/mg sputum) after CCRE challenge. GSTM1 sufficient volunteers had significant, but lower increases in circulating WBCs, PMNs and % sputum PMNs, and no increase in platelets or PMNs/mg sputum. Linear regression analysis adjusted for baseline values of the entire cohort revealed that the GSTM1 null genotype significantly increased circulating WBCs, platelets and % sputum PMNs after challenge.

Conclusion

These data support the hypothesis that the GSTM1 null genotype is a risk factor for increased acute respiratory and systemic inflammatory response to inhaled CCRE. These data are consistent with other observations that the GSTM1 null genotype is associated with increased respiratory, systemic and cardiovascular effects linked to ambient air particulate matter exposure and indicate that the GSTM1 null genotype should be considered a risk factor for adverse health effects associated with exposure to environmental endotoxin.
Airborne cultivable microflora and microbial transfer in farm buildings and rural dwellings
Authors: Normand Anne-Cécile , Sudre Bertrand , Vacheyrou Mallory , Depner Martin , Wouters Inge M , Noss Ilka , Heederik Dick , Hyvärinen Anne , Genuneit Jon , Braun-Fahrländer Charlotte , von Mutius Erika , Piarroux Renaud ,   the GABRIEL-A Study Group
Published: March 2011

Objectives

Exposure to environments rich in microorganisms such as farms has been shown to protect against the development of childhood asthma and allergies. However, it remains unclear where, and how, farm and other rural children are exposed to microbes. Furthermore, the composition of the microbial flora is poorly characterised. We tested the hypothesis that farm children are exposed indoors to substantial levels of viable microbes originating from animal sheds and barns. We also expected that environmental microbial flora on farms and in farm homes would be more complex than in the homes of rural control children.

Methods

Dust samples were collected using passive samplers in the bedrooms of the following groups of children in rural Bavaria, Germany: (i) those living on farms (n=144), (ii) those regularly exposed to farm environments but not living on farms (n=149) and (iii) those never visiting farms (n=150). For farm children, additional samples were collected in animal sheds and barns. All samples were subjected to fungal and bacterial culturing.

Results

Detectable levels of microorganisms were more often found in samples taken from farm dwellings than from other homes. Farm dwellings also showed higher microbial levels. Microbial counts of farm dwelling samples correlated with the counts in corresponding animal sheds and barns.

Conclusions

Microorganisms are transported from animal sheds and barns into farm dwellings. Therefore, children living in these environments are exposed when indoors and when visiting animal sheds and barns. Indoor exposure may also contribute to the protective effect of the farm environment.
What has change management in industry got to do with improving patient safety?
Authors: Noble Douglas J , Lemer Claire , Stanton Emma
Published: March 2011

Background

Healthcare is often in a constant state of change - for political, technological, patient related, and scientific reasons. Yet, for a business where change is the norm, too little time is spent thinking theoretically about how change occurs. One area where change is still needed is in patient safety.

Methods

Presented is an analysis of the literature on change to suggest how this may inform patient safety.

Results

No one change approach guarantees success in patient safety. Success very much depends on selecting the best fit change framework and adapting it to local context. Well regarded change models, like that of Kotter, are not well tested within a healthcare context. Those that are, such as Pettigrew, do not specifically address all the issues associated with patient safety. Kotter's phases of change may be applied in a healthcare context to enhance patient safety.

Conclusion

Kotter's model is well studied in non-healthcare contexts and has potential to be adapted for improving patient safety.
Stress and recovery in junior doctors
Authors: Ochsmann Elke , Lang Jessica , Drexler Hans , Schmid Klaus
Published: March 2011

Objective

Junior doctors are thought to experience increased mental strain in comparison to other occupations. The aim of the present study was to analyse selected work related influencing factors of strain and recovery in junior doctors.

Methods

In September 2006, 1494 young doctors were asked to participate in a postal questionnaire study featuring the Recovery Stress Questionnaire (RESTQ) and additional questions on job specific risk factors. Using hierarchical linear regression analyses the answers of 637 participants with less than 1.5 years work experience in patient care were analysed.

Results

Results revealed that overtime work, as well as lack of performance related feedback from supervisors, were consistently related to increased levels of strain among junior doctors. These risk factors were also predominantly related to recovery. In addition, feedback from colleagues was significantly associated with the recovery sub-scales (except with sleep quality).

Conclusions

Overtime work and performance related feedback from supervisors seem to be important work related factors concerning junior doctors’ levels of strain and recovery. In addition, performance feedback from colleagues seems to be a major resource for recovery. The findings have implications regarding work time regulations and the necessity of leadership skill development training regarding feedback talks and fostering a desirable social climate in the healthcare system for the wellbeing of junior doctors.
Preserved or slightly depressed ejection fraction and outcomes after myocardial infarction
Authors: Badheka Apurva O , Rathod Ankit , Bharadwaj Aditya S , Manickam Palaniappan , Kizilbash Mohammad A , Veeranna Vikas , Jacob Sony , Afonso Luis
Published: March 2011

Background

Left ventricular ejection fraction (EF) in post-myocardial infarction (MI) patients is a strong predictor of adverse cardiovascular events. Although resting EF as measured by transthoracic echocardiography (TTE), contrast ventriculography (CNV), and radionuclide angiography (RNA) exhibit high correlation, there is only modest agreement between these modalities. This study sought to explore whether modality of EF assessment influences prognostication of post-MI patients with normal or slightly reduced EF.

Methods and results

The National Heart, Lung, and Blood Institute (NHLBI) limited access dataset of the Prevention of Events with Angiotensin Converting Enzyme Inhibition (PEACE) Trial (1996–2003, n=8290) comparing trandolapril versus placebo was used. The cohort was partitioned into TTE (n=2582), RNA (n=816), and CNV (n=1155) groups based on modality of EF assessment. EF was a significant predictor of cardiovascular mortality (HR 0.97, 95% CI 0.95 to 0.98; p<0.005) and all cause mortality (HR 0.98, 95% CI 0.97 to 0.99; p=0.0002) on multivariate analysis in this population with preserved or mildly depressed EF. Although CNV, TTE, and RNA groups differed significantly in terms of baseline variables, no appreciable differences were noted between RNA (HR 1.13, 95% CI 0.85 to 1.50; ns) and CNV (HR 1.13, 95% CI 0.99 to 1.27; ns) groups, compared with TTE for all cause mortality. Similarly, no significant differences were observed for cardiovascular mortality between RNA (HR 1.23, 95% CI 0.82 to 1.84; p=0.31) and CNV (HR 1.14, 95% CI 0.78 to 1.67, p=0.49) versus TTE.

Conclusion

EF is a significant predictor of all-cause mortality and cardiovascular mortality in patients with preserved or mildly depressed EF. Modalities of EF measurement are interchangeable and do not play a significant role in prognostication in a post-MI population.
Sleep apnoea in severe aortic stenosis
Authors: Prinz Christian , Bitter Thomas , Oldenburg Olaf , Faber Lothar , Horstkotte Dieter , Piper Cornelia
Published: March 2011

Background

There are as yet no data on the prevalence of sleep apnoea in patients with severe aortic stenosis (AS).

Aims

To assess the occurrence, severity and clinical correlates of sleep apnoea in patients with AS.

Methods

During a 4-month period in 2010, 67 patients were consecutively included in this study, 42 of which (19 men; mean±SD age 72±9 years) had severe AS (aortic valve opening area ≤1.0 cm2); all were investigated with cardiorespiratory polygraphy. Sleep apnoea was diagnosed if the apnoea–hypopnoea index (AHI) (median (lower quartile, upper quartile)) was ≥5/h. The control group of 25 patients matched for age, body mass index and sex had angiographic exclusion of coronary artery disease, regular left ventricular ejection fraction, and no valve disease.

Results

Sleep apnoea was found in 30/42 patients with AS (71%; AHI=23/h (14/h, 36/h)). The severity was significantly greater in patients with severe AS than in the control group (AHI=12/h (8/h, 17/h)) (p<0.01). Half of the patients with sleep apnoea had obstructive sleep apnoea (OSA) (AHI=15/h (9/h, 28/h)), and half had central sleep apnoea (CSA) (AHI=25/h (18/h, 45/h)). New York Heart Association classification and severity of sleep apnoea correlated with η=0.5 (η2=0.3). The severity of CSA correlated with pulmonary artery pressure (r=0.7, p<0.01) and pulmonary capillary wedge pressure (r=0.7, p<0.01). Patients with AS and CSA had a lower Pco  2 than those with OSA and those without sleep apnoea (p<0.01).

Conclusions

Sleep apnoea is common in patients with severe AS. The severity of CSA correlates with pulmonary hypertension, which may suggest that myocardial adaptation is exhausting.
Renin–angiotensin system antagonists in the perioperative setting: clinical consequences and recommendations for practice
Authors: Auron Moises , Harte Brian , Kumar Ajay , Michota Franklin
Published: March 2011

There are no existing guidelines supporting the withdrawal or continuation of renin–angiotensin–aldosterone system (RAAS) antagonists in the preoperative setting. RAAS antagonists include ACE inhibitors, angiotensin II receptor subtype 1 blockers and direct renin inhibitors (eg, aliskiren), as well as the aldosterone antagonists. The use of these agents before surgery has been associated with a variable incidence of hypotension during the initial 30 min after induction of anaesthesia; however, these hypotensive episodes have not been conclusively linked to any significant postoperative complications, although recent data suggest an increase in postoperative morbidity and mortality in patients undergoing coronary artery bypass grafting. Further studies are required to be able to demonstrate if the organ-protective benefits of RAAS antagonists justify their continuation in the perioperative setting. Temporary withdrawal of RAAS antagonists in these patients may prevent or attenuate intraoperative hypotension and hypovolaemia. Alternatively, the increase in RAAS activity and blood pressure expected with cessation of RAAS antagonist therapy may impair regional circulation secondary to an increase in systemic vascular resistance. Full discussion of the potential implications of perioperative RAAS antagonist therapy with the surgical team is important, and strategies to ensure careful monitoring and maintenance of adequate intravenous volume before induction of anaesthesia are essential.
SPECTRAL RENORMALIZATION GROUP AND LOCAL DECAY IN THE STANDARD MODEL OF NON-RELATIVISTIC QUANTUM ELECTRODYNAMICS
Authors: FRÖHLICH JÜRG , GRIESEMER MARCEL , SIGAL ISRAEL MICHAEL
Published: March 2011

We prove a limiting absorption principle for the standard model of non-relativistic quantum electrodynamics (QED) and for Nelson's model describing interactions of electrons with phonons. To this end, we use the spectral renormalization group technique on the continuous spectrum in conjunction with Mourre theory.
RUELLE–LANFORD FUNCTIONS AND LARGE DEVIATIONS FOR ASYMPTOTICALLY DECOUPLED QUANTUM SYSTEMS
Authors: OGATA YOSHIKO , REY-BELLET LUC
Published: March 2011

We recover, expand, and unify quantum (and classical) large deviation results for lattice Gibbs states. The main new ingredient in this paper is a control on the overlap of spectral projections for non-commutative observables. Our proof of large deviations is based on Ruelle–Lanford functions [20, 34] which establishes the existence of a rate function directly by subadditivity arguments, as done in the classical case in [23, 32], instead of relying on Gärtner–Ellis theorem, and cluster expansion or transfer operators as done in the quantum case in [21, 13, 27, 22, 16, 28]. We assume that the Gibbs states are asymptotically decoupled [23, 32], which controls the dependence of observables localized at different spatial locations. In the companion paper [29], we discuss the characterization of rate functions in terms of relative entropies.
A Study on Modulation Configuration of Optoelectronic Oscillators Using Direct Modulation of Semiconductor Lasers
Authors: Kim Jae-Young , Choi Woo-Young , Sung Hyuk-Kee
Published: March 2011

Optoelectronic oscillators (OEOs) are demonstrated using optical single sideband (SSB) which is generated by resonance effect in directly-modulated semiconductor lasers under optical injection. The resonant amplification of modulated optical sideband enhances the optical link efficiency in a target oscillation frequency so that RF threshold gain of OEO can be significantly reduced. The OEOs based on two different modulation configurations – master laser and slave laser modulation – show comparable efficiency and phase noise performance.
Control of the Birefringence Dispersion of an Optical Polymer by Doping with an Inorganic Crystal
Authors: Shafiee Houran , Shikama Kota , Tagaya Akihiro , Hardinghaus Ferdinand , Miyaji Taichi , Köhler Karl , Koike Yasuhiro
Published: March 2011

The birefringence dispersion of a polymer film was controlled by doping with an inorganic birefringent crystal. Nanosized crystals of strontium carbonate (SrCO3) with a needlelike shape of average length of 192 nm were oriented during the preparation of the film by solvent casting, and the contributions of the SrCO3 crystals to the birefringence and to the birefringence dispersion of the composite film were analyzed. A SrCO3-doped polymer film with reverse birefringence dispersion was fabricated, and the birefringence dispersion of this film was shown to be successfully controlled by the presence of the crystals.
Development of a Low-Noise Yellow-Green Laser Using a Yb-Doped Double-Clad Fiber Laser and a Periodically Poled LiNbO3 Waveguide Crystal
Authors: Matsuura Hiroshi , Takagi Takeshi
Published: March 2011

We have developed a yellow-green laser for fluorescence laser microscopes that is based on micro-optics technology and uses a Yb-doped double-clad fiber laser with an etalon and a periodically poled LiNbO3 waveguide crystal. This laser with an acoustic optical modulator (AOM) for analog modulation has an root-mean-square (RMS) noise of less than 2% in operating power range, a maximum optical power of 30 mW at an output wavelength of 555 nm and an extinction ratio of over 22 dB.
Dynamic Recording of 200 Gbytes in Three-Dimensional Optical Disk by a 405 nm Wavelength Picosecond Laser
Authors: Ueda Daisuke , Saito Kimihiro , Iwamura Takashi , Takemoto Yoshihiro , Yamatsu Hisayuki , Horigome Toshihiro , Oyamada Mitsuaki , Hayashi Kunihiko , Tanabe Norihiro , Miyamoto Hirotaka , Nakaoki Ariyoshi , Horigome Junichi , Uchiyama Hiroshi , Yun KyungSung , Kobayashi Seiji
Published: March 2011

We present experimental results of our volumetric optical data storage system. To achieve volumetric recording over a wide depth range of 250 µm in a recording medium, we developed a relay lens system for compensating for the spherical aberration of a high-numerical-aperture (0.85) objective lens. The disk employs a single monolithic recording layer and a reference layer for servo control. A 405-nm-wavelength titanium:sapphire laser that exhibits 2 ps pulse duration and a more than 2 kW peak power is used for recording. We adopted void formation and mark position as recording principles. We have experimentally demonstrated 34-layer dynamic recording, corresponding to a capacity of 200 Gbytes.
A Mean-Field Photoreaction Model for the Pretilt Generation of a Liquid Crystal on Photopolymer Layers upon Ultraviolet Exposure
Authors: Na Jun-Hee , Pae Hyungwu , Kim Jinyool , Yu Chang-Jae , Lee Sin-Doo
Published: March 2011

We present a mean-field photoreaction model for the pretilt generation of a nematic liquid crystal (NLC) on the surfaces of photopolymers upon the exposure of ultraviolet (UV) light. The angular distribution function of photopolymer side chains, calculated in the photoreaction model, is used for determining the surface anchoring energy within the Rapini–Papoular approximation. The pretilt angle transition from the homeotropic alignment to the planar alignment of the NLC is demonstrated in two photopolymers with different alkyl chain lengths as a function of the UV exposure time. The main features of the experimental results agree well with theoretical predictions.
Relaxation Phenomena of a Magnetic Nanoparticle Assembly with Randomly Oriented Anisotropy
Authors: Fang Fang , WenXiao WenXiao , He He , ZhenHui ZhenHui , Chen Chen , DiHu DiHu , En En , YunFei YunFei , Kong Kong , XueDong XueDong
Published: March 2011

The effects of a randomly oriented anisotropy on relaxation phenomena including the memory effect of a noninteracting magnetic nanoparticle assembly, are numerically studied with a localized partition function and a master equation, leading to the following results. During the zero-field-cooled (ZFC) process, the energy barrier histogram changes with temperature, while during the field-cooled (FC) process it remains stable. In the relaxation process after ZFC initialization, the effective energy barrier distribution, which is derived from theTln (t/τ0) (Ttemperature,ttime, and τ0characteristic time constant) scaling curve, only reflects the low-energy region of the energy barrier histogram. The memory effect with temporary cooling during time evolution occurs in the studied assembly even without volume distribution and particle interaction involved.
Photoluminescence Studies of Porous ZnO Nanorods
Authors: Kim Min Su , Yim Kwang Gug , Jeon Su Min , Lee Dong-Yul , Kim Jin Soo , Kim Jong Su , Son Jeong-Sik , Leem Jae-Young
Published: March 2011

Porous ZnO nanorods were prepared by thermal annealing at 700 °C in argon atmosphere. Temperature-dependent photoluminescence (PL) was carried out to investigate the optical properties of the porous ZnO nanorods. The average diameter and density of the pores formed on the surface of the porous ZnO nanorods are 25 nm and 1.2×1010cm-2, respectively. Six peaks at 3.380, 3.366, 3.338, 3.267, 3.227, and 3.198 eV, corresponding to free exciton (FX), neutral donor bound exciton (D0X), first-order longitudinal optical phonon replica of free exciton (FX-1LO), FX-2LO, FX-3LO, and FX-4LO emissions, are obtained at low temperature (10 K). The FX emission peak energy of the porous ZnO nanorods exhibits an anomalous behavior as the temperature is increased to 100 K. The activation energy of the porous ZnO nanorods is found to be about 8.6 meV, and the values of fitting parameters to Varshni's empirical equation are α= 6×10-4eV/K and β= 680 K.
Heterojunction Diodes Comprised of n-Type Silicon and p-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite
Authors: Ohmagari Shinya , Al-Riyami Sausan , Yoshitake Tsuyoshi
Published: March 2011

Heterojunction diodes comprised of p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) and n-type Si, wherein 3 at. % boron-doped UNCD/a-C:H films were deposited on Si substrates by pulsed laser deposition, were electrically studied. The current–voltage (I–V) characteristics showed the typical rectification action with a leakage current density of 4.7 ×10-5 A/cm2 at a reverse voltage of -1 V. The carrier transport is expected to be in generation–recombination process accompanied by tunneling at low forward voltages of 0.1–0.5 V, and to be predominantly in tunneling at 0.5–1.0 V, from ideality factors estimated from the forward I–V curve. Grain boundaries in the UNCD/a-C:H film might act as centers for tunneling. From the capacitance–voltage measurement, the build-in potential of the heterojunction and an active carrier concentration in the p-type UNCD/a-C:H film were estimated to be 0.6 eV and 1.4 ×1017 cm-3, respectively.
Influence of Interface Arrangement on Phonon Heat Transfer in Nanocomposites
Authors: Hsieh Tse-Yang , Yang Jaw-Yen
Published: March 2011

The influence of interface arrangement in two- and three-dimensional silicon–germanium nanostructures on heat transfer is investigated by phonon Boltzmann transport equation model. For all nanocomposites studied here, the thermal conductivity decreases monotonically with increasing interface density and decreases monotonically with decreasing characteristic size. The interface density plays an important role to correlate the size effect of phonon transport. Another factor called structure efficiency, which taking into account both the structure dimensions and the interface arrangement, is also found to affect significantly the thermal conductivities of the nanocomposites. For the structure efficiency of a composite structure, it is found that the superlattice structure has the best structure efficiency in transverse transport and the compacted-wire structure has the best structure efficiency in longitudinal transport. High-dimensional (wire and particle) structures contain large interface density which is beneficial for reducing thermal conductivity. At the same characteristic size, the compacted-particle structure can yield the lowest thermal conductivity in transverse transport and the compacted-wire structure can yield the lowest thermal conductivity in longitudinal transport. The obtained results may provide essential information for the development of bulk-nanostructured thermoelectric devices.
Universal Model for Local Anodic Oxidation Based on Surface Chemistry of Oxide Islands
Authors: Nakamura Masaya , Ogino Toshio
Published: March 2011

We propose a new model for local anodic oxidation using atomic force microscopy (AFM), where surface chemistry is controlled through the voltage applied during the oxidation. The AFM oxidation was performed on Si surfaces with oxide layers as base surfaces, the hydrophilicity of which was controlled by thermal annealing before AFM oxidation. We found that the chemistry on the anodic oxide islands is only determined by the applied voltage and not by the chemical property of the base surface. When the base oxide is too thick to be further oxidized, the surface chemistry remains unchanged with respect to the applied voltage. When the oxide thickness is so thin that anodic re-oxidation occurs, the surface chemistry of the oxide islands is changed by the second anodic oxidation. These experimental results can be interpreted using a universal model for local anodic oxidation that involves the diffusion of OH- molecules in the oxide, the oxidation of Si at the interface accompanying the emission of Si atoms, and the oxidation of the emitted silicons at the oxide surface.
Characterization of Hot-Implanted Fe near the SiO2/Si Interface
Authors: Hoshino Yasushi , Arima Hiroki , Saito Yasunao , Nakata Jyoji
Published: March 2011

We have investigated nanoparticles formed in the vicinity of a SiO2/Si interface by Fe implantation at substrate temperatures of 300, 600, and 800 °C. The implantation energies are selected to assign peak positions of the implanted Fe profiles at the SiO2/Si interface. The size and crystal orientation of the nanoparticles are confirmed by cross-sectional transmission electron microscopy (TEM) and transmission electron diffraction (TED) analysis. The depth profile of implanted Fe was analyzed by Rutherford backscattering spectroscopy (RBS). It is found in the TEM image of the 300 °C-implanted sample that tiny clusters with a mean diameter of 2.4 nm are grown in the SiO2 layer. In addition, some Fe clusters are precipitated in the vicinity of the SiO2/Si interface. On the other hand, we observe nanoclusters with a mean diameter of 3.2 nm at a certain depth in the SiO2 layer for the 600 °C-implanted sample. Some of the clusters in the SiO2 layer have a crystalline structure of α-Fe. Furthermore, β-FeSi2 with comparatively larger diameters of 5–10 nm is found to precipitate at the SiO2/Si interface from the analysis of TEM and TED images. Most of the implanted Fe atoms are segregated either just on the SiO2 surface or at the SiO2/Si interface in the 800 °C-implantation case. The anomalous diffusion of Fe in the SiO2 layer seems to be explained by the ion-beam-irradiation effect at high temperatures.
The Effect of Poling on the Properties of 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 Ceramics
Authors: Uršič Hana , Tellier Jenny , Hrovat Marko , Holc Janez , Drnovšek Silvo , Bobnar Vid , Alguero Miguel , Kosec Marija
Published: March 2011

The effects of the poling field on the structural and electrical properties of 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (0.65PMN–0.35PT) ceramics were investigated. The highest piezoelectric coefficient d
33, coupling coefficients k
p, k
t, and mechanical quality factor Q
m were achieved for ceramics poled at electric fields between 2 and 3.5 kV/mm, whereas the d
33, k
p, k
t, and Q
m of ceramics poled at higher electric fields, i.e., 4 and 4.5 kV/mm, were lower. The non-poled ceramics contained 86% of the monoclinic phase with the space group P
m and 14% of the tetragonal phase with the space group P4m
m. However, the ceramics poled at 2.5 kV/mm contained 99% of the monoclinic phase and the rest is the tetragonal phase. The results show that the ratio of the monoclinic to the tetragonal phases can be changed by the application of a poling electric field and that the extent of this change is dependent on the field strength.