Oxygen intercalation in PVD graphene grown on copper substrates: A decoupling approach.

We investigate the intercalation process of oxygen in-between a PVD-grown graphene layer and different copper substrates as a methodology for reducing the substrate-layer interaction. This growth method leads to an extended defect-free graphene layer that strongly couples with the substrate. We have found, by means of X-ray photoelectron spectroscopy, that after oxygen exposure at different temperatures, ranging from 280 °C to 550 °C, oxygen intercalates at the interface of graphene grown on Cu foil at an optimal temperature of 500 °C. The low energy electron diffraction technique confirms the adsorption of an atomic oxygen adlayer on top of the Cu surface and below graphene after oxygen exposure at elevated temperature, but no oxidation of the substrate is induced. The emergence of the 2D Raman peak, quenched by the large interaction with the substrate, reveals that the intercalation process induces a structural undoing. As suggested by atomic force microscopy, the oxygen intercalation does not change significantly the surface morphology. Moreover, theoretical simulations provide further insights into the electronic and structural undoing process. This protocol opens the door to an efficient methodology to weaken the graphene-substrate interaction for a more efficient transfer to arbitrary surfaces.

Reversible Graphene decoupling by NaCl photo-dissociation.

We describe the reversible intercalation of Na under graphene on Ir(111) by photo-dissociation of a previously adsorbed NaCl overlayer. After room temperature evaporation, NaCl adsorbs on top of graphene forming a bilayer. With a combination of electron diffraction and photoemission techniques we demonstrate that the NaCl overlayer dissociates upon a short exposure to an X-ray beam. As a result, chlorine desorbs while sodium intercalates under the graphene, inducing an electronic decoupling from the underlying metal. Low energy electron diffraction shows the disappearance of the moiré pattern when Na intercalates between graphene and iridium. Analysis of the Na 2p core-level by X-ray photoelectron spectroscopy shows a chemical change from NaCl to metallic buried Na at the graphene/Ir interface. The intercalation-decoupling process leads to a n-doped graphene due to the charge transfer from the Na, as revealed by constant energy angle resolved X-ray photoemission maps. Moreover, the process is reversible by a mild annealing of the samples without damaging the graphene.

Recession, employment and self-rated health: a study on the gender gap.

OBJECTIVES: Employment status and economic recession have been associated with negative effects on self-rated health, and this effect differs by gender. We analysed the effects of the Spanish economic recession in terms of self-rated health, its differential effect among genders and its influence on gender gap. STUDY DESIGN: Repeated cross-sectional study using Spanish health surveys (2001-2014). METHODS: Logistic regression models were conducted to explore the association between self-rated health and employment status and its evolution over time and gender. To test the impact of the economic recession, pooled data regression models were conducted. RESULTS: In this study, we considered 104,577 subjects. During the last 15 years, women have entered the labour market, leading to wide changes in the Spanish traditional family roles. Instead of an increasing proportion of women workers, gender employment differences persist. Therefore, in 2014, the prevalence of workers was 55.77% in men, whereas in women, it was 44.01%. Self-rated health trends during the economic recession differ by gender, with women improving slightly their self-rated health from a low self-rated health prevalence of 38.76% in 2001 to 33.78% in 2014. On the contrary, men seem more vulnerable to employment circumstances, which have led to substantial reduction in the gender gap. CONCLUSIONS: Although a gender gap persists, the change in socio-economic roles seems to increase women's self-rated health, reducing this gap. It is important to promote women's labour market inclusion, even in economic recession periods.

Spectroscopic characterization of the on-surface induced (cyclo)dehydrogenation of a N-heteroaromatic compound on noble metal surfaces.

New nanoarchitectures can be built from polycyclic aromatic hydrocarbons (PAHs) by exploiting the capability of some metal surfaces for inducing cyclodehydrogenation reactions. This bottom-up approach allows the formation of nanostructures with a different dimensionality from the same precursor as a consequence of the diffusion and coupling of the PAHs adsorbed on the surface. In this work we present a thorough study, by means of a combination of X-ray photoemission spectroscopy, near-edge X-ray absorption fine structure and scanning tunneling microscopy with first principle calculations of the structural and chemical transformations undergone by pyridyl-substituted dibenzo[5]helicene on three coinage surfaces, namely Cu(110), Cu(111) and Au(111). Upon annealing, on-surface chemical reactions are promoted affecting the adsorbate/substrate and the molecule/molecule interactions. This thermally induced process favours the transformation from diffusing isolated molecules to polymeric nanographene chains and finally to N-doped graphene.

Diabetes mellitus mortality in Spanish cities: Trends and geographical inequalities.

AIM: To analyze the geographical pattern of diabetes mellitus (DM) mortality and its association with socioeconomic factors in 26 Spanish cities. METHODS: We conducted an ecological study of DM mortality trends with two cross-sectional cuts (1996-2001; 2002-2007) using census tract (CT) as the unit of analysis. Smoothed standardized mortality rates (sSMR) were calculated using Bayesian models, and a socioeconomic deprivation score was calculated for each CT. RESULTS: In total, 27,757 deaths by DM were recorded, with higher mortality rates observed in men and in the period 1996-2001. For men, a significant association between CT deprivation score and DM mortality was observed in 6 cities in the first study period and in 7 cities in the second period. The highest relative risk was observed in Pamplona (RR, 5.13; 95% credible interval (95%CI), 1.32-15.16). For women, a significant association between CT deprivation score and DM mortality was observed in 13 cities in the first period and 8 in the second. The strongest association was observed in San Sebastián (RR, 3.44; 95%CI, 1.25-7.36). DM mortality remained stable in the majority of cities, although a marked decrease was observed in some cities, including Madrid (RR, 0.67 and 0.64 for men and women, respectively). CONCLUSIONS: Our findings demonstrate clear inequalities in DM mortality in Spain. These inequalities remained constant over time are were more marked in women. Detection of high-risk areas is crucial for the implementation of specific interventions.

High-quality PVD graphene growth by fullerene decomposition on Cu foils.

We present a new protocol to grow large-area, high-quality single-layer graphene on Cu foils at relatively low temperatures. We use C60 molecules evaporated in ultra high vacuum conditions as carbon source. This clean environment results in a strong reduction of oxygen-containing groups as depicted by X-ray photoelectron spectroscopy (XPS). Unzipping of C60 is thermally promoted by annealing the substrate at 800ºC during evaporation. The graphene layer extends over areas larger than the Cu crystallite size, although it is changing its orientation with respect to the surface in the wrinkles and grain boundaries, producing a modulated ring in the low energy electron diffraction (LEED) pattern. This protocol is a self-limiting process leading exclusively to one single graphene layer. Raman spectroscopy confirms the high quality of the grown graphene. This layer exhibits an unperturbed Dirac-cone with a clear n-doping of 0.77 eV, which is caused by the interaction between graphene and substrate. Density functional theory (DFT) calculations show that this interaction can be induced by a coupling between graphene and substrate at specific points of the structure leading to a local sp3 configuration, which also contribute to the D-band in the Raman spectra.

Formation of titanium monoxide (001) single-crystalline thin film induced by ion bombardment of titanium dioxide (110).

A plethora of technological applications justify why titanium dioxide is probably the most studied oxide, and an optimal exploitation of its properties quite frequently requires a controlled modification of the surface. Low-energy ion bombardment is one of the most extended techniques for this purpose and has been recently used in titanium oxides, among other applications, to favour resistive switching mechanisms or to form transparent conductive layers. Surfaces modified in this way are frequently described as reduced and defective, with a high density of oxygen vacancies. Here we show, at variance with this view, that high ion doses on rutile titanium dioxide (110) induce its transformation into a nanometric and single-crystalline titanium monoxide (001) thin film with rocksalt structure. The discovery of this ability may pave the way to new technical applications of ion bombardment not previously reported, which can be used to fabricate heterostructures and interfaces.

Initial stages of FeO growth on Ru(0001).

We study how FeO wüstite films on Ru(0001) grow by oxygen-assisted molecular beam epitaxy at elevated temperatures (800­900 K). The nucleation and growth of FeO islands are observed in real time by low-energy electron microscopy (LEEM). When the growth is performed in an oxygen pressure of 10(−6) Torr, the islands are of bilayer thickness (Fe­O­Fe­O). In contrast, under a pressure of 10(−8) Torr, the islands are a single FeO layer thick. We propose that the film thickness is controlled by the concentration of oxygen adsorbed on the Ru. More specifically, when monolayer growth increases the adsorbed oxygen concentration above a limiting value, its growth is suppressed. Increasing the temperature at a fixed oxygen pressure decreases the density of FeO islands. However, the nucleation density is not a monotonic function of oxygen pressure.

Surface defects and their influence on surface properties.

Surface defects have a profound influence on many attributes of materials, therefore experimental techniques and specific studies focused on their controlled generation and properties are mandatory. We have carried out a thorough study of the role of surface defects on a variety of physico-chemical properties of metals and oxides, using different experimental techniques and molecular dynamics simulations. In particular, we have studied the defects formed upon bombardment with Ar+ ions in a reconstructed Au(100) surface at very low ion doses. At room temperature, the pristine defects are mainly single vacancies, which diffuse by collective atomic motions, then cluster and collapse, resulting in 2D dislocation dipoles. These dislocations exhibit an enhanced chemical reactivity due to the elastic stress of their cores. We have also performed indentation tests of flat and stepped Au(111) samples with an atomic force microscope, revealing noticeable differences in their mechanical behavior when probed at the nanoscale. Thus, the stepped sample has a 20% smaller Young's modulus, 40% smaller yield point and 50% smaller shear stress. These differences, as well as reversible, quasiplastic behavior of the stepped sample up to a critical load, are due to the active role of steps as dislocation nucleation centers. In contrast, a TiO2(110) surface, modified with ion bombardment, does not show noticeable changes in its nanomechanical properties, which is an indication of the very different mechanical responses of oxides compared to simple metals at the nanoscale. Finally, we show how surface defects affect the chemical activity of a Pt(111) surface when exposed to methanol. The nature of the adsorbed species and the dynamics of the surface reactions are modified in the presence of surface defects, rendering the defective surface into a more robust state against catalytic poisoning.

Vulnerable population and health status in a neighbourhood in Zaragoza (Spain).

This paper aims to identify the inter-relationships between the social factors that influence epidemiological patterns in the city neighbourhood of Casablanca, Zaragoza (Spain). Data for a cross-sectional survey were collected between January 2008 and April 2008 from a representative random sample of 1032 residents aged more than 15 years. The study interview contained information scales on healthcare behaviours, treatment evaluation, the number of medical consultations in the weeks pervious to the interview and the perceived health status of the respondents, using The Health Perception Questionnaire. The global index (continuous variable) allowed inferences to be made on the individual's perception of his/her own health. The assessment of social vulnerability was based on the occupational, educational and economic conditions of the interviewees. An individual was considered to belong to a vulnerable subeconomic group if he/she had a personal income of 6000 euros or less; or had no formal education or had been educated up to primary school level only; or was not in paid employment at the time of the interview. A descriptive and comparative analysis of the vulnerable and non-vulnerable population groups for perceived and diagnosed health variables was undertaken using parametric and non-parametric tests. A total of 550 interviewees (53.3%) were considered vulnerable people. Low level of instruction (primary or no education) was the main characteristic of this group (356 subjects, 64.7% of those identified as vulnerable). Binary logistic regression was used to analyse the association between belonging to the vulnerable group and a number of health variables adjusted for gender, age and area of residence. The vulnerable group had worse levels of perceived health even when controlled for gender and area of residence. In Casablanca, the place of residence is an important social stratification indicator reflected in the characteristics of the vulnerable population group and its perceived health.

[Temporal orientation and cognitive impairment]. / Orientacion en el tiempo y deterioro cognitivo.

INTRODUCTION: Temporal orientation is a component of most screening tests for diagnosing cognitive impairment. Correct temporal orientation involves activating both semantic information (concepts of the calendar date) and episodic information (remembering the current date). AIMS: The aim of this study was to assess the diagnostic usefulness of a technique for evaluating temporal orientation, which was open-ended, and scoring the semantic and episodic information thus generated (0-10 points). SUBJECTS AND METHODS: A total of 24 subjects without impairment, 77 patients with mild cognitive impairment (MCI) and 62 patients with dementia were evaluated by means of a 30-point mini-mental/mini-examination, semantic verbal fluency test, global deterioration scale, mini-mental-type temporal orientation and open-ended temporal orientation tests. The areas under the curve (aROC), sensitivity and specificity for dementia and cognitive impairment at any degree (MCI and dementia) were analysed. RESULTS: Open-ended temporal orientation presented a greater area under the curve (aROC: 0.90) for discrimination between patients with dementia and without dementia (MCI and without impairment) and an aROC of 0.83 for discrimination between patients with MCI or dementia and without impairment. For dementia, with a cut-off point equal to or below 6, sensitivity was 0.96 and specificity was 0.68, and for MCI with dementia, with a cut-off point equal to or below 7, sensitivity was 0.72 and specificity was 0.92. CONCLUSIONS: The usefulness, conciseness and strategic position of this technique in examining mental status make it suitable as an instrument for screening for cognitive impairment. It has a high level of sensitivity with low specificity for dementia and low sensitivity with high specificity for any degree of impairment.

Prospective randomised phase II study of docetaxel versus paclitaxel administered weekly in patients with non-small-cell lung cancer previously treated with platinum-based chemotherapy.

BACKGROUND: Docetaxel and paclitaxel have activity in the second-line treatment of non-small-cell lung cancer (NSCLC), and can be administered as weekly schedules. This phase II randomised study was designed to test the efficacy and toxicity of both taxanes in patients with NSCLC previously treated with platinum-based chemotherapy. PATIENTS AND METHODS: Patients (n = 71) with documented NSCLC were randomised to receive docetaxel (n = 35 patients; 36 mg/m(2)) or paclitaxel (n = 36 patients; 80 mg/m(2)) as a 1 h weekly infusion for 6 weeks followed by a 2-week rest. The cycles were repeated until disease progression or non-acceptable toxicities occurred. RESULTS: Treatment achieved partial response of one versus five patients, median time-to-progression of 74 versus 68 days, and overall survival of 184 versus 105 days, with docetaxel and paclitaxel, respectively. The most common non-haematological toxicities were (docetaxel versus paclitaxel): grade 3/4 pulmonary toxicity in seven versus one patient; grade 2/3 diarrhoea in nine versus five; and grade 3/4 haematological toxicities occurred in two versus four patients. There were no treatment-related deaths. CONCLUSIONS: Docetaxel and paclitaxel administered weekly have discrete efficacy in patients with NSCLC previously treated with platinum-based chemotherapy. The higher non-haematological toxicity of docetaxel, particularly pulmonary toxicity and diarrhoea, is of concern and warrants further investigation.

Prevalence and intensity of soil-transmitted helminthiasis in the city of Portoviejo (Ecuador).

We studied the stool samples of 151 school children in a district of the city of Portoviejo (Ecuador) in order to determine the prevalence and intensity of soil-transmitted helminthiasis (STH) and their relationships with anthropometric indices. The samples were analyzed with the semiquantitative Kato-Katz technique and the intensity of infections was categorized as light, moderate or high according to the thresholds set by the World Health Organization. Prevalence of soil transmitted helmintiasis was 65% (92 out of 141 collected samples), Ascaris lumbricoides was the most common STH (63%) followed by Trichuris trichiura (10%) and hookworm (1.4%). Heavy intensity infections were found in 8.5% of the stool samples, with T. trichiura showing higher worm burdens than A. lumbricoides. Sixteen percent of the children were below the third percentile for weight (wasted), while 27% were below the third percentile for height (stunted). A significant relationship was found between the worm burden and the degree of stunting. This study suggests that the periodic administration of an antihelminthic drug should be targeted to preschool and school children to allow a normal growth spurt and prevent stunting.

A phase II trial of cyclophosphamide, epirubicin and vinorelbine in the treatment of advanced breast cancer.

BACKGROUND: Vinorelbine (Navelbin; N) has proven to be active in patients with advanced breast cancer (ABC) and cyclophosphamide (C) and epirubicin (Epiadriamycin: E) are still among the main cytostatic agents against this tumor. On this basis was carried out a study to determine the activity and toxicity of the combination of these three agents (CEN). PATIENTS AND METHOD: From April 1996 to March 1998, 59 patients with ABC were recruited of whom 56 were found eligible and evaluable for toxicity and 55 for activity. The treatment regimen was C: 400 mg/m2, E: 30 mg/m2 and N: 25 mg/m2 administered intravenously on days 1 and 8 of a 28-day cycle. RESULTS: The median number of cycles administered was 6 (range: 1-16). The most common hematological toxicity was grade (G) 3 and 4 neutropenia occurring in 36% of patients, associated with fever in 7% of them. Grade 3-4 thrombocytopenia and anemia occurred in 5% and 7%, respectively. Other G2-G3 non hematologic toxicities were: N/vomiting in 34%, alopecia in 73% and mucositis in 11% of patients. An objective response was achieved in 28 of 56 patients (50%) (95% confidence interval (CI): 37-63%): complete response (CR) in 9%, partial response (PR) in 41%. The median duration of response, time to progression and overall survival time was 54, 47 and 90 weeks, respectively. CONCLUSION: The CEN combination at these doses and treatment schedule appears to have acceptable tolerability but there is no apparent improvement in therapeutic efficacy when compared to other regimens used as first line treatment in ABC.

Phase III trial of cyclophosphamide, epirubicin, fluorouracil (CEF) versus cyclophosphamide, mitoxantrone, fluorouracil (CNF) in women with metastatic breast cancer.

BACKGROUND: The mitoxantrone combination CNF and the epirubicin combination CEF have shown similar activity and less toxicity than the standard CAF combination in metastatic breast cancer (MBC). A prospective randomised study was started to compare safety and activity between CEF and CNF administered using a classical chemotherapeutic schedule in MBC. PATIENTS AND METHODS: From December 1987 to June 1993, 151 patients were randomised to receive cyclophosphamide (C) 100 mg m(-2) p.o. days 1-14, fluorouracil (F) 500 mg m(-2) i.v. days 1 and 8, and epirubicin (E) 30 mg m(-2) i.v. days 1 and 8, or mitoxantrone (N) 6 mg m(-2) i.v. days 1 and 8, every 4 weeks. Seventy-three patients were eligible for CEF and 72 for CNF. RESULTS: Objective responses were observed in 61.6% of the CEF group and 44.4% in CNF group (p = 0.004). The median duration of response was 64 weeks in CEF and 50 weeks in CNF group (p = 0.02) and median time to progression was 51 and 33 weeks, respectively (p = 0.0004). At the time of analysis, all except six patients (one in CNF and five in CEF) had died and the median survival time in the CEF group was longer than in CNF (74.4 weeks vs 51.4 weeks; log-rank chi2 test p = 0.015). CNF produced more hematologic toxicity than CEF (WHO scale; grades 2-4); leucopenia 84% vs 68% (p = 0.03) and thrombocytopenia 17% vs 4.5% (p = 0.01); CEF caused more grade 2 and 3 alopecia: 93% vs 70% (p = 0.001). CONCLUSION: The combination CEF using this schedule and dosage in metastatic breast cancer is more effective with less toxicity than CNF, except for alopecia, and was associated with longer survival.