Nonradiative limitations to plasmon propagation in chains of metallic nanoparticles

This is the author accepted manuscript. The final version is available from the American Physical Society via the DOI in this recordWe investigate the collective plasmonic modes in a chain of metallic nanoparticles that are coupled by near-field interactions. The size- and momentum-dependent nonradiative Landau damping and radiative decay rates are calculated analytically within an open quantum system approach. These decay rates determine the excitation propagation along the chain. In particular, the behavior of the radiative decay rate as a function of the plasmon wavelength leads to a transition from an exponential decay of the collective excitation for short distances to an algebraic decay for large distances. Importantly, we show that the exponential decay is of a purely nonradiative origin. Our transparent model enables us to provide analytical expressions for the polarization-dependent plasmon excitation profile along the chain and for the associated propagation length. Our theoretical analysis constitutes an important step in the quest for the optimal conditions for plasmonic propagation in nanoparticle chains.CNRSAN

Cost-effectiveness of replacing skeletal traction by interlocked intramedullary nailing for femoral shaft fractures in a provincial trauma hospital in Cambodia

In this article the costs and effectiveness of introducing the SIGN nailing system for femoral shaft fractures in a provincial trauma hospital in Cambodia are compared to those of Perkin’s traction treatment. At an average cost per patient of $1,107 in the traction group and$888 in the nail group (p < 0.01), and with better clinical outcomes in the nail group, internal fixation is more cost-effective than conservative treatment

Rectal cancer in old age –is it appropriately managed? Evidence from population-based analysis of routine data across the English national health service

Background: There is significant debate as to where to draw the line between undertreating older rectal cancer patients and minimising treatment risks. This study sought to examine the use of radical rectal cancer treatments and associated outcomes in relation to age across the English NHS. Methods: Patient, tumour and treatment characteristics for all patients diagnosed with a first primary rectal cancer in England between 1st April 2009 and 31st December 2014 were obtained from the CORECT-R data repository. Descriptive analyses and adjusted logistic regression models were undertaken to examine any association between age and the use of major resection and post-surgical outcomes. Funnel plots were used to show variation in adjusted rates of major resection. Results: The proportion of patients who underwent a major surgical resection fell from 66.5% to 31.7%, amongst those aged <70 and aged ≥80 respectively. After adjustment, 30-day post-operative mortality, failure to rescue and prolonged length of stay were significantly higher among the oldest group when compared to the youngest. Patient reported outcomes were not significantly worse amongst older patients. Significant variation was observed in adjusted surgical resection rates in the oldest patients between NHS Trusts. The probability of death due to cancer was comparable across all age groups. Conclusions: Older patients who are selected for surgery have good outcomes, often comparable to their younger counterparts. Significant variation in the treatment of older patients could not be explained by differences in measured characteristics and required further investigation

Interventions to Promote Cancer Awareness and Early Presentation: Systematic Review

Low cancer awareness contributes to delay in presentation for cancer symptoms and may lead to delay in cancer diagnosis. The aim of this study was to review the evidence for the effectiveness of interventions to raise cancer awareness and promote early presentation in cancer to inform policy and future research. We searched bibliographic databases and reference lists for randomised controlled trials of interventions delivered to individuals, and controlled or uncontrolled studies of interventions delivered to communities. We found some evidence that interventions delivered to individuals modestly increase cancer awareness in the short term and insufficient evidence that they promote early presentation. We found limited evidence that public education campaigns reduce stage at presentation of breast cancer, malignant melanoma and retinoblastoma

Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background

The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability

The science of clinical practice: disease diagnosis or patient prognosis? Evidence about "what is likely to happen" should shape clinical practice.

BACKGROUND: Diagnosis is the traditional basis for decision-making in clinical practice. Evidence is often lacking about future benefits and harms of these decisions for patients diagnosed with and without disease. We propose that a model of clinical practice focused on patient prognosis and predicting the likelihood of future outcomes may be more useful. DISCUSSION: Disease diagnosis can provide crucial information for clinical decisions that influence outcome in serious acute illness. However, the central role of diagnosis in clinical practice is challenged by evidence that it does not always benefit patients and that factors other than disease are important in determining patient outcome. The concept of disease as a dichotomous 'yes' or 'no' is challenged by the frequent use of diagnostic indicators with continuous distributions, such as blood sugar, which are better understood as contributing information about the probability of a patient's future outcome. Moreover, many illnesses, such as chronic fatigue, cannot usefully be labelled from a disease-diagnosis perspective. In such cases, a prognostic model provides an alternative framework for clinical practice that extends beyond disease and diagnosis and incorporates a wide range of information to predict future patient outcomes and to guide decisions to improve them. Such information embraces non-disease factors and genetic and other biomarkers which influence outcome. SUMMARY: Patient prognosis can provide the framework for modern clinical practice to integrate information from the expanding biological, social, and clinical database for more effective and efficient care

Detection of micrometastasis by cytokeratin 20 RT-PCR is limited due to stable background transcription in granulocytes

The reverse transcription polymerase chain reaction (RT-PCR) amplification of cytokeratin 20 (CK20) mRNA is considered a promising candidate method for the detection of circulating tumour cells in bone marrow and peripheral blood of cancer patients. In this study we have investigated the diagnostic specificity of the CK20 mRNA detection in samples from healthy donors (HD; n = 33), intensive care units patients (ICU; n = 20) and bone marrow obtained from patients suffering from chronic inflammatory diseases (CID; n = 14). RNAs purified from stabilized lysates showed positive results in 24% of the HD group (8/33), 35% of the ICU group (8/20) and in 40% of the CID group (5/14). The use of Ficoll gradients to separate nucleated cells completely restored the specificity of this CK20 RT-PCR assay. The CK20-expressing cells are positively identified to belong to the granulocyte fraction of leucocytes, which appear to express the gene on a background level. Our results demonstrate for the first time that CK20 mRNA expression is not limited to epithelium. Its occurrence in normal granulocytes has to be considered in tests designed to detect circulating cancer cells or micrometastases. © 1999 Cancer Research Campaig

Recent trends in cutaneous malignant melanoma in the Yorkshire region of England; incidence, mortality and survival in relation to stage of disease, 1993–2003

The aim of this study was to investigate recent trends in incidence, mortality and survival in patients diagnosed with malignant melanoma (MM) in relation to stage (Breslow thickness). Cases of primary invasive and in situ MM diagnosed between 1st January 1993 and 31st December 2003 in the former Yorkshire Health Authority were identified from cancer registry data. Over the study period, the incidence of invasive MM increased from 5.4 to 9.7 per 100 000 in male subjects and from 7.5 to 13.1 per 100 000 in female subjects. Most of this increase was seen in thin tumours (<1.5 mm). Thin tumours were more likely to be diagnosed in the younger age groups and be classified as superficial spreading melanoma. In situ melanoma rates increased only slightly. Over the same time period, mortality rates have been relatively constant in both male and female subjects. Five-year relative survival varied from 91.8% (95% CI 90.4–93.1) for patients with thin tumours to 41.5% (95% CI 36.7–46.3) for those with thick tumours. In multivariable analyses, Breslow thickness was the most important prognostic factor. Age, sex and level of deprivation were also identified as independent prognostic factors. The trends in incidence suggest that the increase is real, rather than an artefact of increased scrutiny, implying that primary prevention in the Yorkshire area of the UK has failed to control trends in incidence. Mortality, in contrast, appears to be levelling off, indicating that secondary prevention has been more effective