Coupling strength control in photonic crystal/photonic wire multiple cavity devices

Resonance splitting has been demonstrated for two coupled micro-cavities with control of the free spectral range between the resonance peaks, together with a normalised transmission level of approximately 60%. Coupled micro-cavity-based structures that were separated by two closely spaced in-line coupler sections between the two micro-cavities have also been successfully fabricated and measured. The coupling strength of the two cavities was controlled via the use of hole tapering in the middle section between the two cavities. 2D finite-difference time-domain simulation shows close agreement with the results of measurements

An avalanche-photodiode-based photon-number-resolving detector

Avalanche photodiodes are widely used as practical detectors of single photons.1 Although conventional devices respond to one or more photons, they cannot resolve the number in the incident pulse or short time interval. However, such photon number resolving detectors are urgently needed for applications in quantum computing,2-4 communications5 and interferometry,6 as well as for extending the applicability of quantum detection generally. Here we show that, contrary to current belief,3,4 avalanche photodiodes are capable of detecting photon number, using a technique to measure very weak avalanches at the early stage of their development. Under such conditions the output signal from the avalanche photodiode is proportional to the number of photons in the incident pulse. As a compact, mass-manufactured device, operating without cryogens and at telecom wavelengths, it offers a practical solution for photon number detection.Comment: 12 pages, 4 figure

A review of the methodological features of systematic reviews in maternal medicine

Background In maternal medicine, research evidence is scattered making it difficult to access information for clinical decision making. Systematic reviews of good methodological quality are essential to provide valid inferences and to produce usable evidence summaries to guide management. This review assesses the methodological features of existing systematic reviews in maternal medicine, comparing Cochrane and non-Cochrane reviews in maternal medicine. Methods Medline, Embase, Database of Reviews of Effectiveness (DARE) and Cochrane Database of Systematic Reviews (CDSR) were searched for relevant reviews published between 2001 and 2006. We selected those reviews in which a minimum of two databases were searched and the primary outcome was related to the maternal condition. The selected reviews were assessed for information on framing of question, literature search and methods of review. Results Out of 2846 citations, 68 reviews were selected. Among these, 39 (57%) were Cochrane reviews. Most of the reviews (50/68, 74%) evaluated therapeutic interventions. Overall, 54/68 (79%) addressed a focussed question. Although 64/68 (94%) reviews had a detailed search description, only 17/68 (25%) searched without language restriction. 32/68 (47%) attempted to include unpublished data and 11/68 (16%) assessed for the risk of missing studies quantitatively. The reviews had deficiencies in the assessment of validity of studies and exploration for heterogeneity. When compared to Cochrane reviews, other reviews were significantly inferior in specifying questions (OR 20.3, 95% CI 1.1–381.3, p = 0.04), framing focussed questions (OR 30.9, 95% CI 3.7- 256.2, p = 0.001), use of unpublished data (OR 5.6, 95% CI 1.9–16.4, p = 0.002), assessment for heterogeneity (OR 38.1, 95%CI 2.1, 688.2, p = 0.01) and use of meta-analyses (OR 3.7, 95% CI 1.3–10.8, p = 0.02). Conclusion This study identifies areas which have a strong influence on maternal morbidity and mortality but lack good quality systematic reviews. Overall quality of the existing systematic reviews was variable. Cochrane reviews were of better quality as compared to other reviews. There is a need for good quality systematic reviews to inform practice in maternal medicine

In Vivo Oxygen Uptake into the Human Cornea

PURPOSE. We provide a new procedure to quantify in situ corneal oxygen uptake using the micropolarographic Clark electrode. METHODS. Traditionally, upon placing a membrane-covered Clark microelectrode onto a human cornea, the resulting polarographic signal is interpreted as the oxygen partial pressure at the anterior corneal surface. However, the Clark electrode operates at a limiting current. Hence, oxygen flux is directly detected rather than partial pressure. We corrected this misunderstanding and devised a new analysis to quantify oxygen uptake into the cornea. The proposed analysis is applied to new polarographic data for 10 human subjects during open-eye oxygen uptake. RESULTS. Average open-eye corneal oxygen uptake over 10 subjects is approximately 11 lL/(cm 2 h), approximately five times larger than the average reported by researchers who invoke the original mathematical analysis. Application of the classical interpretation scheme to our experimental data also garners uptake values that are approximately a factor of three to five times smaller than those obtained with our new procedure. CONCLUSIONS. The classical procedure originally developed by Fatt and colleagues misinterprets the behavior of the Clark microelectrode. We corrected the analysis of the in situ polarographic technique to provide a simple yet rigorous procedure for analyzing both previous data in the literature and those newly obtained. Our proposed interpretation scheme thus provides a reliable tool for in vivo assessment of corneal oxygen uptake. (Invest Ophthalmol Vis Sci. 2012;53:6331-6337

The Impact of Pandemic Influenza H1N1 on Health-Related Quality of Life: A Prospective Population-Based Study

BACKGROUND: While the H1N1v influenza pandemic in 2009 was clinically mild, with a low case-fatality rate, the overall disease burden measured in quality-adjusted life years (QALY) lost has not been estimated. Such a measure would allow comparison with other diseases and assessment of the cost-effectiveness of pandemic control measures. METHODS AND FINDINGS: Cases of H1N1v confirmed by polymerase chain reaction (PCR) and PCR negative cases with similar influenza-like illness (ILI controls) in 7 regions of England were sent two questionnaires, one within a week of symptom onset and one two weeks later, requesting information on duration of illness, work loss and antiviral use together with EQ-5D questionnaires. Results were compared with those for seasonal influenza from a systematic literature review. A total QALY loss for the 2009 pandemic in England was calculated based on the estimated total clinical cases and reported deaths. A total of 655 questionnaires were sent and 296 (45%) returned. Symptoms and average illness duration were similar between confirmed cases and ILI controls (8.8 days and 8.7 days respectively). Days off work were greater for cases than ILI controls (7.3 and 4.9 days respectively, p  =  0.003). The quality-adjusted life days lost was 2.92 for confirmed cases and 2.74 for ILI controls, with a reduction in QALY loss after prompt use of antivirals in confirmed cases. The overall QALY loss in the pandemic was estimated at 28,126 QALYs (22,267 discounted) of which 40% was due to deaths (24% with discounting). CONCLUSION: Given the global public health significance of influenza, it is remarkable that no previous prospective study of the QALY loss of influenza using standardised and well validated methods has been performed. Although the QALY loss was minor for individual patients, the estimated total burden of influenza over the pandemic was substantial when compared to other infectious diseases

Soy consumption and risk of COPD and respiratory symptoms: a case-control study in Japan

<p>Abstract</p> <p>Background</p> <p>To investigate the relationship between soy consumption, COPD risk and the prevalence of respiratory symptoms, a case-control study was conducted in Japan.</p> <p>Methods</p> <p>A total of 278 eligible patients (244 men and 34 women), aged 50–75 years with COPD diagnosed within the past four years, were referred by respiratory physicians, while 340 controls (272 men and 68 women) were recruited from the community. All participants underwent spirometric measurements of respiratory function. Information on demographics, lifestyle characteristics and habitual food consumption was obtained using a structured questionnaire.</p> <p>Results</p> <p>Total soy consumption was positively correlated with observed lung function measures. The mean soy intake was significantly higher among controls (59.98, SD 50.23 g/day) than cases (44.84, SD 28.5 g/day). A significant reduction in COPD risk was evident for highest versus lowest quartile of daily intake of total soybean products, with adjusted odds ratio (OR) 0.392, 95% CI 0.194–0.793, <it>p </it>for trend 0.001. Similar decreases in COPD risk were associated with frequent and higher intake of soy foods such as tofu and bean sprouts, whereas respiratory symptoms were inversely associated with high consumption of soy foods, especially for breathlessness (OR 0.989, 95% CI 0.982–0.996).</p> <p>Conclusion</p> <p>Increasing soy consumption was associated with a decreased risk of COPD and breathlessness.</p

Discovery of New Molecular Subtypes in Oesophageal Adenocarcinoma

A large number of patients suffering from oesophageal adenocarcinomas do not respond to conventional chemotherapy; therefore, it is necessary to identify new predictive biomarkers and patient signatures to improve patient outcomes and therapy selections. We analysed 87 formalin-fixed and paraffin-embedded (FFPE) oesophageal adenocarcinoma tissue samples with a reverse phase protein array (RPPA) to examine the expression of 17 cancer-related signalling molecules. Protein expression levels were analysed by unsupervised hierarchical clustering and correlated with clinicopathological parameters and overall patient survival. Proteomic analyses revealed a new, very promising molecular subtype of oesophageal adenocarcinoma patients characterised by low levels of the HSP27 family proteins and high expression of those of the HER family with positive lymph nodes, distant metastases and short overall survival. After confirmation in other independent studies, our results could be the foundation for the development of a Her2-targeted treatment option for this new patient subgroup of oesophageal adenocarcinoma

Predicting Weight Outcomes in Preadolescence: The Role of Toddlers? Self-regulation Skills and the Temperament Dimension of Pleasure

Objective To investigate the role of toddlers? self-regulation skills and temperament in predicting weight outcomes in preadolescence. Method Participants for this study included 195 children (114 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. At 2 years of age, participants participated in several laboratory tasks designed to assess their self-regulation abilities, including emotion regulation, sustained attention, and delay of gratification, while parents filled out a temperament questionnaire to assess toddlers? pleasure expression. Height and weight measures were collected when children were 4, 5, 7, and 10 years of age. Children also filled out a body image and eating questionnaire at the 10 year visit. Results Self-regulation skills in toddlers were associated with both BMI development, pediatric obesity, and body image/eating concerns. The temperament dimension of pleasure was also associated with BMI development and pediatric obesity but not body image/eating concerns. Conclusion Self-regulation difficulties across domains as well as temperament based pleasure in toddlers represented significant individual risk factors for the development of pediatric obesity eight years later. Early self-regulation difficulties also contributed to body image and eating concerns that typically accompanied overweight children. The mechanisms by which early self-regulation skills and temperament based pleasure may contribute to the development of pediatric obesity and associated weight concerns are discussed