Ellipsometric measurements by use of photon pairs generated by spontaneous parametric down-conversion

We present a novel interferometric technique for performing ellipsometric measurements. This technique relies on the use of a non-classical optical source, namely, polarization-entangled twin photons generated by spontaneous parametric down-conversion from a nonlinear crystal, in conjunction with a coincidence-detection scheme. Ellipsometric measurements acquired with this scheme are absolute; i.e., they do not require source and detector calibration.Comment: 10 pages, accepted for publication in Optics Letter

A lattice model for the line tension of a sessile drop

Within a semi--infinite thre--dimensional lattice gas model describing the coexistence of two phases on a substrate, we study, by cluster expansion techniques, the free energy (line tension) associated with the contact line between the two phases and the substrate. We show that this line tension, is given at low temperature by a convergent series whose leading term is negative, and equals 0 at zero temperature

Au/TiO2(110) interfacial reconstruction stability from ab initio

We determine the stability and properties of interfaces of low-index Au surfaces adhered to TiO2(110), using density functional theory energy density calculations. We consider Au(100) and Au(111) epitaxies on rutile TiO2(110) surface, as observed in experiments. For each epitaxy, we consider several different interfaces: Au(111)//TiO2(110) and Au(100)//TiO2(110), with and without bridging oxygen, Au(111) on 1x2 added-row TiO2(110) reconstruction, and Au(111) on a proposed 1x2 TiO reconstruction. The density functional theory energy density method computes the energy changes on each of the atoms while forming the interface, and evaluates the work of adhesion to determine the equilibrium interfacial structure.Comment: 20 pages, 11 figure

Dryland restoration successes in the Sahel and Greater Horn of Africa show how to increase scale and impact

Drylands occupy more than 40% of the world’s land area and are home to some two billion people. This includes a disproportionate number of the world’s poorest people, who live in degraded and severely degraded landscapes. The United Nations Convention to Combat Desertification states on its website that 12 million hectares are lost annually to desertification and drought, and that more than 1.5 billion people are directly dependent on land that is being degraded, leading to US$42 billion in lost earnings each year. In Africa, three million hectares of forest are lost annually, along with an estimated 3% of GDP, through depleted soils. The result is that two-thirds of Africa’s forests, farmlands and pastures are now degraded. This means that millions of Africans have to live with malnutrition and poverty, and in the absence of options this further forces the poor to overexploit their natural resources to survive. This in turn intensifies the effects of climate change and hinders economic development, threatening ecological functions that are vital to national economies

Rigorous Probabilistic Analysis of Equilibrium Crystal Shapes

The rigorous microscopic theory of equilibrium crystal shapes has made enormous progress during the last decade. We review here the main results which have been obtained, both in two and higher dimensions. In particular, we describe how the phenomenological Wulff and Winterbottom constructions can be derived from the microscopic description provided by the equilibrium statistical mechanics of lattice gases. We focus on the main conceptual issues and describe the central ideas of the existing approaches.Comment: To appear in the March 2000 special issue of Journal of Mathematical Physics on Probabilistic Methods in Statistical Physic

A randomised controlled trial of patient led training in medical education: protocol

<p>Abstract</p> <p>Background</p> <p>Estimates suggest that approximately 1 in 10 patients admitted to hospital experience an adverse event resulting in harm. Methods to improve patient safety have concentrated on developing safer systems of care and promoting changes in professional behaviour. There is a growing international interest in the development of interventions that promote the role of patients preventing error, but limited evidence of effectiveness of such interventions. The present study aims to undertake a randomised controlled trial of patient-led teaching of junior doctors about patient safety.</p> <p>Methods/Design</p> <p>A randomised cluster controlled trial will be conducted. The intervention will be incorporated into the mandatory training of junior doctors training programme on patient safety. The study will be conducted in the Yorkshire and Humber region in the North of England. Patients who have experienced a safety incident in the NHS will be recruited. Patients will be identified through National Patient Safety Champions and local Trust contacts. Patients will receive training and be supported to talk to small groups of trainees about their experiences. The primary aim of the patient-led teaching module is to increase the awareness of patient safety issues amongst doctors, allow reflection on their own attitudes towards safety and promote an optimal culture among the doctors to improve safety in practice. A mixture of qualitative and quantitative methods will be used to evaluate the impact of the intervention, using the Attitudes to Patient Safety Questionnaire (APSQ) as our primary quantitative outcome, as well as focus groups and semi-structured interviews.</p> <p>Discussion</p> <p>The research team face a number of challenges in developing the intervention, including integrating a new method of teaching into an existing curriculum, facilitating effective patient involvement and identifying suitable outcome measures.</p> <p>Trial Registration</p> <p>Current controlled Trials: <a href="http://www.controlled-trials.com/ISRCTN94241579">ISRCTN94241579</a></p

A practical approach to establishing a critical care outreach service: An expert panel research design

Background: For over two decades, nurse-led critical care outreach services have improved the recognition, response, and management of deteriorating patients in general hospital wards, yet variation in terms, design, implementation, and evaluation of such services continue. For those establishing a critical care outreach service, these factors make the literature difficult to interpret and translate to the real-world setting. Aim: The aim of this study was to provide a practical approach to establishing a critical care outreach service in the hospital setting. Method: An international expert panel of clinicians, managers, and academics with experience in implementing, developing, operationalising, educating, and evaluating critical care outreach services collaborated to synthesise evidence, experience, and clinical judgment to develop a practical approach for those establishing a critical care outreach service. A rapid review of the literature identified publications relevant to the study. A modified Delphi technique was used to achieve expert panel consensus particularly in areas where insufficient published literature or ambiguities existed. Findings: There were 502 publications sourced from the rapid review, of which 104 were relevant and reviewed. Using the modified Delphi technique, the expert panel identified five key components needed to establish a critical care outreach service: (i) approaches to service delivery, (ii) education and training, (iii) organisational engagement, (iv) clinical governance, and (v) monitoring and evaluation. Conclusion: An expert panel research design successfully synthesised evidence, experience, and clinical judgement to provide a practical approach for those establishing a critical care outreach service. This method of research will likely be valuable in other areas of practice where terms are used interchangeably, and the literature is diverse and lacking a single approach to practice

Growth, profits and technological choice: The case of the Lancashire cotton textile industry

Using Lancashire textile industry company case studies and financial records, mainly from the period just before the First World War, the processes of growth and decline are re-examined. These are considered by reference to the nature of Lancashire entrepreneurship and the impact on technological choice. Capital accumulation, associated wealth distributions and the character of Lancashire business organisation were sybiotically linked to the success of the industry before 1914. However, the legacy of that accumulation in later decades, chronic overcapacity, formed a barrier to reconstruction and enhanced the preciptious decline of a once great industry

Adjuvant chemotherapy in upper tract urothelial carcinoma (the POUT trial): a phase 3, open-label, randomised controlled trial

Background: Urothelial carcinomas of the upper urinary tract (UTUCs) are rare, with poorer stage-for-stage prognosis than urothelial carcinomas of the urinary bladder. No international consensus exists on the benefit of adjuvant chemotherapy for patients with UTUCs after nephroureterectomy with curative intent. The POUT (Peri-Operative chemotherapy versus sUrveillance in upper Tract urothelial cancer) trial aimed to assess the efficacy of systemic platinum-based chemotherapy in patients with UTUCs. Methods: We did a phase 3, open-label, randomised controlled trial at 71 hospitals in the UK. We recruited patients with UTUC after nephroureterectomy staged as either pT2–T4 pN0–N3 M0 or pTany N1–3 M0. We randomly allocated participants centrally (1:1) to either surveillance or four 21-day cycles of chemotherapy, using a minimisation algorithm with a random element. Chemotherapy was either cisplatin (70 mg/m²) or carboplatin (area under the curve [AUC]4·5/AUC5, for glomerular filtration rate <50 mL/min only) administered intravenously on day 1 and gemcitabine (1000 mg/m²) administered intravenously on days 1 and 8; chemotherapy was initiated within 90 days of surgery. Follow-up included standard cystoscopic, radiological, and clinical assessments. The primary endpoint was disease-free survival analysed by intention to treat with a Peto-Haybittle stopping rule for (in)efficacy. The trial is registered with ClinicalTrials.gov, NCT01993979. A preplanned interim analysis met the efficacy criterion for early closure after recruitment of 261 participants. Findings: Between June 19, 2012, and Nov 8, 2017, we enrolled 261 participants from 57 of 71 open study sites. 132 patients were assigned chemotherapy and 129 surveillance. One participant allocated chemotherapy withdrew consent for data use after randomisation and was excluded from analyses. Adjuvant chemotherapy significantly improved disease-free survival (hazard ratio 0·45, 95% CI 0·30–0·68; p=0·0001) at a median follow-up of 30·3 months (IQR 18·0–47·5). 3-year event-free estimates were 71% (95% CI 61–78) and 46% (36–56) for chemotherapy and surveillance, respectively. 55 (44%) of 126 participants who started chemotherapy had acute grade 3 or worse treatment-emergent adverse events, which accorded with frequently reported events for the chemotherapy regimen. Five (4%) of 129 patients managed by surveillance had acute grade 3 or worse emergent adverse events. No treatment-related deaths were reported. Interpretation: Gemcitabine–platinum combination chemotherapy initiated within 90 days after nephroureterectomy significantly improved disease-free survival in patients with locally advanced UTUC. Adjuvant platinum-based chemotherapy should be considered a new standard of care after nephroureterectomy for this patient population. Funding: Cancer Research UK