PTCDA growth on Ge(111)-[Formula: see text] surfaces: a scanning tunneling microscopy study.

The initial stages of growth of PTCDA (3,4,9,10 perylene tetracarboxylic dianhydride) at room temperature (RT) on Ge(111)-[Formula: see text] surfaces have been studied by means of scanning tunneling microscopy (STM) under ultrahigh vacuum conditions. The results show that PTCDA molecules have a high mobility at RT on the well ordered areas of the semiconductor substrate, since nucleation is only observed in domain walls, steps and surface defects. However, no molecular ordering has been detected at submonolayer coverage. For higher coverages, the formation of three-dimensional (3D) molecular islands has been observed. These 3D islands present a crystalline nature as demostrated by molecularly resolved STM images. According to these STM measurements, PTCDA molecules are ordered in a herringbone structure, similar to the one observed in PTCDA bulk crystals. Moreover, the 3D crystallites are grown on top of a disordered molecular layer, which acts as a passivating layer.

[Cerebellar abscesses secondary to infection of an occipital dermal sinus]. / Abscesos cerebelosos secundarios a infección de seno dérmico occipital.

A dermal sinus is a congenital defect arising from a closure failure of the neural tube that results in different degrees of communication between the skin and the central nervous system. A dermal sinus can occur anywhere from the root of the nose to the conus medullaris, and the occipital location is the second most common. Dermal sinuses are often found in association with dermoid or epidermoid cysts and less frequently with teratomas. Patients with an occipital dermoid cyst associated with a dermal sinus can develop meningitis and/or abscesses as the first clinical manifestation of the disease due to the dermoid cyst itself becoming abscessed or to the formation of secondary abscesses; few cases of the formation of secondary abscesses have been reported. We present a case of a dermoid cyst associated with an infected dermal sinus and posterior development of cerebellar abscesses and hydrocephalus.

Point defects on graphene on metals.

Understanding the coupling of graphene with its local environment is critical to be able to integrate it in tomorrow's electronic devices. Here we show how the presence of a metallic substrate affects the properties of an atomically tailored graphene layer. We have deliberately introduced single carbon vacancies on a graphene monolayer grown on a Pt(111) surface and investigated its impact in the electronic, structural, and magnetic properties of the graphene layer. Our low temperature scanning tunneling microscopy studies, complemented by density functional theory, show the existence of a broad electronic resonance above the Fermi energy associated with the vacancies. Vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in freestanding graphene layers.

Health-related quality of life in individuals with metabolic syndrome: A cross-sectional study.

INTRODUCTION AND OBJECTIVES: Metabolic syndrome (MetS) is a combination of various cardiovascular risk factors with a major impact on morbidity and premature mortality. However, the impact of MetS on self-reported health-related quality of life (HRQoL) is unknown. This study evaluated the HRQoL in a Spanish adult population aged 55 years and older with MetS. METHOD: A cross-sectional analysis was performed with baseline data from the PREDIMED-Plus multicentre randomized trial. The participants were 6430 men and women aged 55-75 years with overweight/obesity (body mass index ≥27 and ≤40kg/m2) and MetS. The SF-36 questionnaire was used as a tool to measure HRQoL. Scores were calculated on each scale of the SF-36 by gender and age. RESULTS: Participants showed higher scores in the social function (mean 85.9, 95% CI; 85.4-86.4) and emotional role scales (mean 86.8, 95% CI; 86.0-87.5). By contrast, the worst scores were obtained in the aggregated physical dimensions. In addition, men obtained higher scores than women on all scales. Among men, the worst score was obtained in general health (mean 65.6, 95% CI; 65.0-66.2), and among women, in body pain (mean 54.3, 95%CI; 53.4-55.2). A significant decrease was found in the aggregated physical dimensions score among participants 70-75 years old, but an increased one in the aggregated mental dimensions, compared to younger participants. CONCLUSIONS: Our results reflect that the MetS may negatively affect HRQoL in the aggregated physical dimensions, body pain in women, and general health in men. However, this adverse association was absent for the psychological dimensions of HRQoL, which were less affected.

Preventing sintering of nanoclusters on graphene by radical adsorption.

Metal nanoclusters, supported on inert substrates, exhibiting well-defined shapes and sizes in a broad range of temperatures are a major object of desire in nanotechnology. Here, a technique is presented that improves the thermal stability of monodisperse and crystalline transition metal nanoclusters grown in a regular array on metal-supported graphene. To stabilize the clusters after growth under ultrahigh vacuum the system composed of the aggregates and the graphene/metal interface is exposed to radicals resulting from the dissociation of diatomic gases. As a model system we have used Pt as the metal element for cluster growth and the template consisting of the moiré pattern resulting from the lattice mismatch between graphene and the Ir(111) surface. The study has been performed for deuterium and oxygen radicals, which interact very differently with graphene. Our results reveal that after radical exposure the thermally activated motion of Pt nanoclusters to adjacent moiré cells and the subsequent sintering of neighbor aggregates are avoided, most pronounced for the case of atomic O. For the case of D the limits of the improvement are given by radical desorption, whereas for the case of O they are defined by an interplay between coalescence and graphene etching followed by Pt intercalation, which can be controlled by the amount of exposure. Finally, we determined the mechanism of how radical adsorption improves the thermal stability of the aggregates.

Oxygen orders differently under graphene: new superstructures on Ir(111).

Using scanning tunneling microscopy, the oxygen adsorbate superstructures on bare Ir(111) are identified and compared to the ones formed by intercalation in between graphene and the Ir(111) substrate. For bare Ir(111) we observe O-(2 × 2) and O-(2 × 1) structures, thereby clarifying a persistent uncertainty about the existence of these structures and the role of defects for their stability. For the case of graphene-covered Ir(111), oxygen intercalation superstructures can be imaged through the graphene monolayer by choosing proper tunneling conditions. Depending on the pressure, temperature and duration of O2 exposure as well as on the graphene morphology, O-(2 × 2), O-(√3×√3)-R30°, O-(2 × 1) and O-(2√3 × 2√3)-R30° superstructures with respect to Ir(111) are observed under the graphene cover. Two of these structures, the O-(√3 × âˆš3)-R30° and the (2√3 × 2√3)-R30° structure are only observed when the graphene layer is on top. Phase coexistence and formation conditions of the intercalation structures between graphene and Ir(111) are analyzed. The experimental results are compared to density functional theory calculations including dispersive forces. The existence of these phases under graphene and their absence on bare Ir(111) are discussed in terms of possible changes in the adsorbate-substrate interaction due to the presence of the graphene cover.

[Vascular access guidelines for hemodialysis]. / Guías de acceso vascular en hemodiálisis.

Quality of vascular access (VA) has a remarkable influence in hemodialysis patients outcomes. Dysfunction of VA represents a capital cause of morbi-mortality of these patients as well an increase in economical. Spanish Society of Neprhology, aware of the problem, has decided to carry out a revision of the issue with the aim of providing help in comprehensión and treatment related with VA problems, and achieving an homogenization of practices in three mayor aspects: to increase arteriovenous fistula utilization as first vascular access, to increment vascular access monitoring practice and rationalise central catheters use. We present a consensus document elaborated by a multidisciplinar group composed by nephrologists, vascular surgeons, interventional radiologysts, infectious diseases specialists and nephrological nurses. Along six chapters that cover patient education, creation of VA, care, monitoring, complications and central catheters, we present the state of the art and propose guidelines for the best practice, according different evidence based degrees, with the intention to provide help at the professionals in order to make aproppiate decissions. Several quality standars are also included.

Tug-of-war between corrugation and binding energy: revealing the formation of multiple moiré patterns on a strongly interacting graphene-metal system.

The formation of multidomain epitaxial graphene on Rh(111) under ultra-high vacuum (UHV) conditions has been characterized by scanning tunnelling microscopy (STM) measurements and density functional theory (DFT) calculations. At variance with the accepted view for strongly interacting graphene-metal systems, we clearly demonstrate the formation of different rotational domains leading to multiple moiré structures with a wide distribution of surface periodicities. Experiments reveal a correlation between the STM apparent corrugation and the lattice parameter of the moiré unit cell, with corrugations of just 30-40 pm for the smallest moirés. DFT calculations for a relevant selection of these moiré patterns show much larger height differences and a non-monotonic behaviour with the moiré size. Simulations based on non-equilibrium Green's function (NEGF) methods reproduce quantitatively the experimental trend and provide a detailed understanding of the interplay between electronic and geometric contributions in the STM contrast of graphene systems. Our study sheds light on the subtle energy balance among strain, corrugation and binding that drives the formation of the moiré patterns in all graphene/metal systems and suggests an explanation for the success of an effective model only based on the lattice mismatch. Although low values of the strain energy are a necessary condition, it is the ability of graphene to corrugate in order to maximize the areas of favourable graphene-metal interactions that finally selects the stable configurations.

Monophosphoryl lipid A protects against gram-positive sepsis and tumor necrosis factor.

Monophosphoryl lipid A (MPL) is a less toxic derivative of lipid A that enhances survival from endotoxemia. This study examined whether MPL induced resistance to Gram-positive sepsis and cytokines. Mice were administered MPL or saline (phosphate-buffered saline) and challenged 24 h later with live Staphylococcus aureus (SA), staphylococcus enterotoxin B (SEB), toxic shock syndrome toxin (TSST-1), and tumor necrosis factor (TNF). Survival was determined at 72 h. A separate set of animals was phlebotomized for determination of cytokines. MPL increased survival from S. aureus bacteremia from 20 to 87% (p < .05). Interleukin-6 (IL-6) and interleukin-1 (IL-1) and TNF were also significantly decreased. SEB and TSST survival were enhanced from 10 to 90% (p < .05). In SEB-treated animals, TNF and IL-6 levels were significantly decreased. Survival from TNF infusion was increased from 20 to 100% with MPL, however, no significant differences in cytokines were observed. These data suggest that MPL induces resistance to Gram-positive sepsis and cytokine-mediated activity.

Three year prospective follow up of the peritoneal access.

Peritoneal access-related complications were prospectively studied in 54 peritoneal catheters placed in 49 patients between January 1994 and December 96 in a single centre. There were no perioperative complications. Five (9%) catheters were removed because of catheter-derived complications (3 outflow obstruction, 2 leak), 4 (7.4%) because of peritonitis and 1 was spontaneously extruded. Complications included 4 (7.4%) migrations with outflow obstruction, 6 (11%) leaks and 27 episodes of exit site infection occurring in 16 (30%) catheters. Six catheters suffered more than one infection. Exit site infection in the first month after catheter placement is a risk factor for multiple exit site infections by different bacteria and for catheter removal.

Towards scalable nano-engineering of graphene.

By merging bottom-up and top-down strategies we tailor graphene's electronic properties within nanometer accuracy, which opens up the possibility to design optical and plasmonic circuitries at will. In a first step, graphene electronic properties are macroscopically modified exploiting the periodic potential generated by the self assembly of metal cluster superlattices on a graphene/Ir(111) surface. We then demonstrate that individual metal clusters can be selectively removed by a STM tip with perfect reproducibility and that the structures so created are stable even at room temperature. This enables one to nanopattern circuits down to the 2.5 nm only limited by the periodicity of the Moiré-pattern, i.e., by the distance between neighbouring clusters, and different electronic and optical properties should prevail in the covered and uncovered regions. The method can be carried out on micro-meter-sized regions with clusters of different materials permitting to tune the strength of the periodic potential.

Health-related quality of life in individuals with metabolic syndrome: a cross-sectional study / Calidad de vida relacionada con la salud en individuos con síndrome metabólico: un estudio descriptivo

INTRODUCTION AND OBJECTIVES: Metabolic syndrome (MetS) is a combination of various cardiovascular risk factors with a major impact on morbidity and premature mortality. However, the impact of MetS on self-reported health-related quality of life (HRQoL) is unknown. This study evaluated the HRQoL in a Spanish adult population aged 55 years and older with MetS. METHOD: A cross-sectional analysis was performed with baseline data from the PREDIMED-Plus multicentre randomized trial. The participants were 6430 men and women aged 55-75 years with overweight/obesity (body mass index ≥27 and ≤40kg/m2) and MetS. The SF-36 questionnaire was used as a tool to measure HRQoL. Scores were calculated on each scale of the SF-36 by gender and age. RESULTS: Participants showed higher scores in the social function (mean 85.9, 95% CI; 85.4-86.4) and emotional role scales (mean 86.8, 95% CI; 86.0-87.5). By contrast, the worst scores were obtained in the aggregated physical dimensions. In addition, men obtained higher scores than women on all scales. Among men, the worst score was obtained in general health (mean 65.6, 95% CI; 65.0-66.2), and among women, in body pain (mean 54.3, 95%CI; 53.4-55.2). A significant decrease was found in the aggregated physical dimensions score among participants 70-75 years old, but an increased one in the aggregated mental dimensions, compared to younger participants. CONCLUSIONS: Our results reflect that the MetS may negatively affect HRQoL in the aggregated physical dimensions, body pain in women, and general health in men. However, this adverse association was absent for the psychological dimensions of HRQoL, which were less affected

INTRODUCCIÓN Y OBJETIVOS: El síndrome metabólico (SM) es la combinación de diversos factores de riesgo cardiovascular que pueden derivar en un mayor impacto en la morbimortalidad prematura. Sin embargo, el impacto del SM en la calidad de vida relacionada con la salud (CVRS) es desconocido. El objetivo de este estudio es evaluar la CVRS en la población adulta española de 55 años o más con SM. MÉTODOS: Se realizó un análisis transversal con los datos del ensayo PREDIMED-Plus. Seis mil cuatrocientos treinta varones y mujeres entre 55-75 años con sobrepeso/obesidad y SM. El instrumento de medida de la CVRS fue el cuestionario SF-36. Cada escala del SF-36 fue descrita y estratificada por sexo. RESULTADOS: Los participantes mostraron valores más altos en las escalas función social (media: 85,9; IC 95%: 85,4-86,4) y rol emocional (media: 86,8; IC 95%: 86,0-87,5). En los varones, la peor puntuación fue en la dimensión salud general (media: 65,6; IC 95%: 65,0-66,2) y en las mujeres el dolor corporal (media: 54,3; IC 95%: 53,4-55,2). Además, los varones obtuvieron puntuaciones más altas en todas las escalas. En la escala función física en varones se encontró una disminución significativa de la CVRS en los participantes entre 70 y 75 años en comparación con los más jóvenes. Las peores puntuaciones se obtuvieron en las dimensiones físicas agregadas. CONCLUSIONES: El SM afecta de manera negativa a la CVRS en las dimensiones agregadas físicas, haciendo especial hincapié en la esfera dolor corporal en mujeres y salud general en varones. Sin embargo, las esferas psicológicas se encuentran menos afectadas por el SM

[The botanical project of the Malaspina expedition]. / El proyecto botánico de la expedición Malaspina.

Concluding the XVIIIth century, the monarchy of Carlos III patronizes the expedition Malaspina with the goal of exploring the continents of America, Asia and Oceania. On their political aspect the journey persecuted the reformation of the obsolescent colonial Spanish model, and in their scientific facet the development of a project of investigation in agreement with the European interests. Our goal is to define the botanical studies accomplished by the naturalists of the expedition Malaspina in relationship with the scientific policy that from the Royal Botanical Garden from Madrid the Spanish crown projected for their overseas territories.

[The biological time]. / El tiempo biológico.

Fabio Colonna's De glossopetris dissertatio is part of the biological time. Announces the dawn of a paleontology that understood nature as a closed and orderly system ruled by a perfect, natural codex. The Neapolitan intellectual climate, characteristic of the transit from XVIIth to XVIIIth century, converge in a process of institutionalization of science.

[Pharmacology-biochemistry and physiopathology of tardive dyskinesia: review of the latest findings and controversies]. / Farmacología-bioquímica y fisiopatología de la disquinesia tardía: revisión de los progresos y controversias.

Tardive dyskinesia is described as a distinct neurological entity. Its probable etiology, pathophysiology and biochemical pharmacology are reviewed and discussed in the light of the latest findings.

Choice of dialysis membrane does not influence the outcome of residual renal function in haemodialysis patients.

It has been recently proposed that haemodialysis membrane choice may influence the maintenance of residual renal function. The aim of the present study was to prospectively analyse the effect of membrane choice on the outcome of renal function in patients entering a chronic haemodialysis programme. Twenty-two patients from four hospitals have been randomly assigned to be dialysed with either polysulphone (PSF)/polyacrylonitrile (PAN) (group A; n = 9), or cuprophane membranes (group B; n = 13). Basal and monthly serum biochemistry, residual creatinine clearance (Ccr) and urine volume (Vu), pharmacological and dialytic treatment, diet, and haemodialysis-related complications were recorded. A significant decrease was observed in the two most relevant variables, i.e. remnant Ccr and Vu, within 3 months of starting haemodialysis, with stabilization during the further follow-up. Such decrease was similar (P NS) for both groups A and B throughout the 9-month observation period. In conclusion, our results suggest that the choice of haemodialysis membrane does not influence the outcome of the residual renal function. Renal function decreased significantly within 3 months on haemodialysis, independently of the type of dialyser membrane.

Liver disease patterns in hemodialysis patients with antibodies to hepatitis C virus.

The present study correlated histopathology and diagnostic tests in hemodialysis patients with serologic markers for hepatitis C virus (HCV). Hepatitis C virus infection was found in 65 of 163 patients, as assessed by anti-c100-3 (ELISA 1), anti-c22-3, c33C (ELISA 2), and RIBA 2. Several histopathologic patterns were found in 33 liver samples from HCV-positive individuals: cirrhosis (n = 3), chronic active hepatitis (n = 14), chronic persistent hepatitis (n = 2), isolated hemosiderosis (n = 5), reactive hepatitis (n = 6), and others (n = 3). There was a positive correlation between time from the first aminotransferase peak and histologic damage (P = 0.015). However, the severity of liver disease did not correlate with the intensity of RIBA 2 positivity, mean levels or pattern of aminotransferases elevation, or markers of past hepatitis B virus infection. Moreover, aminotransferases were persistently normal in three patients with severe liver disease and were elevated in 10 patients with only mild changes. In 19 biopsied patients, the presence of plasma HCV RNA was examined by the polymerase chain reaction (PCR), which was positive in 15 of the 19 biopsy specimens. The ability of PCR positivity to predict the histologic severity of the disease was insufficient: four patients with minor liver damage had positive PCR and two patients with significant liver damage had negative PCR. No further correlations of PCR positivity were found with the other biochemical or immunologic markers of HCV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscesos cerebelosos secundarios a infección de seno dérmico occipital / Cerebellar abscesses secondary to infection of an occipital dermal sinus

El seno dérmico es un defecto congénito del cierre del tubo neural que condiciona una comunicación en diferentes grados entre la piel y el sistema nervioso central. Se puede situar desde la raíz nasal hasta el cono medular, siendo la localización occipital la segunda en frecuencia. Se encuentra frecuentemente asociado con quiste dermoide o epidermoide, siendo más rara la asociación a teratomas. Los pacientes con quiste dermoide occipital asociado a seno dérmico pueden desarrollar meningitis y/o formación de abscesos como primera manifestación clínica, debido a la abscesificación del quiste dermoide en sí mismo o bien a la formación de abscesos secundarios, siendo esta última una entidad escasamente descrita en la literatura. Se presenta un caso de quiste dermoide asociado a seno dérmico infectado con desarrollo posterior de abscesos cerebelosos e hidrocefalia(AU)

A dermal sinus is a congenital defect arising from a closure failure of the neural tube that results in different degrees of communication between the skin and the central nervous system. A dermal sinus can occur anywhere from the root of the nose to the conus medullaris, and the occipital location is the second most common. Dermal sinuses are often found in association with dermoid or epidermoid cysts and less frequently with teratomas. Patients with an occipital dermoid cyst associated with a dermal sinus can develop meningitis and/or abscesses as the first clinical manifestation of the disease due to the dermoid cyst itself becoming abscessed or to the formation of secondary abscesses; few cases of the formation of secondary abscesses have been reported. We present a case of a dermoid cyst associated with an infected dermal sinus and posterior development of cerebellar abscesses and hydrocephalus(AU)

Acute lung injury/acute respiratory distress syndrome: a need for education

OBJECTIVE: To examine the timeliness of the diagnosis of patients with ALI/ARDS at the San Juan VA Medical Intensive Care Unit. We were also interested in determining the incidence and the overall 28-day mortality for ARDS during the study period. METHODS: Retrospective record review of all admissions to the San Juan Veterans Affairs Medical ICU during a two-year period (1997-1998). RESULTS: During the study period, 587 patients were admitted to the medical ICU. All had APACHE II scoring performed during their first 24 hours of admission. Twenty-three patients were found to have an A-a gradient of 350 or less. However, two patients were later identified as having radiographic changes compatible with Congestive Heart Failure and were excluded from the study. The incidence of ALI/ARDS was found to be 3.6 per cent at our institution. Of the 21 patients with ARDS, in only 4 the diagnosis of ARDS was documented on their charts. CONCLUSION: Our findings suggest that education in the recognition of ARDS should be aggressively done. In order to implement the recently published successful strategies in the mechanical ventilation of patients with ARDS, it should be first recognized. Our patients need it.