Conductance of Sidewall-Functionalized Carbon Nanotubes: Universal Dependence on Adsorption Sites

We use density functional theory to study the effect of molecular adsorbates on the conductance of metallic carbon nanotubes (CNT). The five molecules considered (NO2, NH2, H, COOH, OH) lead to very similar scattering of the electrons. The adsorption of a single molecule suppresses one of the two available transport channels at the Fermi level while the other is left undisturbed. If more molecules are adsorbed on the same sublattice, the remaining open channel may or may not be blocked, depending on the relative position of the adsorbates. If the relative positions satisfy a simple geometric condition, this channel remains fully open independently of the number of adsorbed molecules.Peer reviewe

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

Waning habitats due to climate change: effects of streamflow and temperature changes at the rear edge of the distribution of a cold-water fish

[EN] Climate changes affect aquatic ecosystems by altering temperatures and precipitation patterns, and the rear edges of the distributions of cold-water species are especially sensitive to these effects. The main goal of this study was to predict in detail how changes in air temperature and precipitation will affect streamflow, the thermal habitat of a cold-water fish (the brown trout, Salmo trutta), and the synergistic relationships among these variables at the rear edge of the natural distribution of brown trout. Thirty-one sites in 14 mountain rivers and streams were studied in central Spain. Models of streamflow were built for several of these sites using M5 model trees, and a non-linear regression method was used to estimate stream temperatures. Nine global climate models simulations for Representative Concentration Pathways RCP4.5 and RCP8.5 scenarios were downscaled to the local level. Significant reductions in streamflow were predicted to occur in all of the basins (max. ¿49¿%) by the year 2099, and seasonal differences were noted between the basins. The stream temperature models showed relationships between the model parameters, geology and hydrologic responses. Temperature was sensitive to streamflow in one set of streams, and summer reductions in streamflow contributed to additional stream temperature increases (max. 3.6¿°C), although the sites that are most dependent on deep aquifers will likely resist warming to a greater degree. The predicted increases in water temperatures were as high as 4.0¿°C. Temperature and streamflow changes will cause a shift in the rear edge of the distribution of this species. However, geology will affect the extent of this shift. Approaches like the one used herein have proven to be useful in planning the prevention and mitigation of the negative effects of climate change by differentiating areas based on the risk level and viability of fish populations.We are grateful to the Consejería de Medio Ambiente y O.T. of the Government of Castilla y León, especially to Mariano Anchuelo, Fabián Mateo and the forest ranger team of Navafría. Also, we are indebted to the Sierra of Guadarrama National Park staff, and especially with Juan Bielva and Ángel Rubio for the temperature data of Lozoya stream. Juan Diego Alcaraz is the author of the temperature data of the Ebrón Basin. Valérie Ouellet and two anonymous referees provided valuable comments that substantially improved the original manuscript. The World Climate Research Programme’s Working Group on Coupled Modelling is responsible for the 5th Coupled Model Intercomparison Project, and we thank the climate modelling groups for producing and making available their model output. Climate change study was partially funded by the Ministerio de Agricultura, Alimentación y Medio Ambiente of Spain through the Fundación para la Investigación del Clima (http://www.ficlima.org/); by the European Union, DG for Environment (DURERO project. C1.3913442); by the Ministerio de Economía y Competitividad of Spain (IMPADAPT project CGL2013-48424-C2-1-R); and by FEDER funds of the European CommissionSantiago, J.; Muñoz Mas, R.; Solana-Gutierrez, J.; García De Jalón Lastra, DM.; Alonso, C.; Martinez-Capel, F.; Pórtoles, J.... (2017). Waning habitats due to climate change: effects of streamflow and temperature changes at the rear edge of the distribution of a cold-water fish. Hydrology and Earth System Sciences Discussions. 21:4073-4101. https://doi.org/10.5194/hess-2016-606S407341012

Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome in Spain: Clinical and Genetic Characterization

Hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC) is a very rare hereditary disorder characterized by cutaneous leiomyomas (CLMs), uterine leiomyomas (ULMs), renal cysts (RCys) and renal cell cancers (RCCs). We aimed to describe the genetics, clinical features and potential genotype-phenotype associations in the largest cohort of fumarate hydratase enzyme mutation carriers known from Spain using a multicentre, retrospective study of individuals with a genetic or clinical diagnosis of HLRCC. We collected clinical information from medical records, analysed genetic variants and looked for genotype-phenotype associations. Analyses were performed using R 3.6.0. software. We included 197 individuals: 74 index cases and 123 relatives. CLMs were diagnosed in 65% of patients, ULMs in 90% of women, RCys in 37% and RCC in 10.9%. Twenty-seven different pathogenic variants were detected, 12 (44%) of them not reported previously. Patients with missense pathogenic variants showed higher frequencies of CLMs, ULMs and RCys, than those with loss-of-function variants (p = 0.0380, p = 0.0015 and p = 0.024, respectively). This is the first report of patients with HLRCC from Spain. The frequency of RCCs was lower than those reported in the previously published series. Individuals with missense pathogenic variants had higher frequencies of CLMs, ULMs and RCys

Carbon nanotubes as heat dissipaters in microelectronics

We review our recent modelling work of carbon nanotubes as potential candidates for heat dissipation in microelectronics cooling. In the first part, we analyze the impact of nanotube defects on their thermal transport properties. In the second part, we investigate the loss of thermal properties of nanotubes in presence of an interface with various substances, including air and water. Comparison with previous works is established whenever is possible.Comment: 14 pages, 21 figures, 5 table

Design of solar cell materials via soft X-ray spectroscopy

This overview illustrates how spectroscopy with soft X-rays can assist the development of new materials and new designs for solar cells. The starting point is the general layout of a solar cell, which consists of a light absorber sandwiched between an electron donor and an electron acceptor. There are four relevant energy levels that can be measured with a combination of X-ray absorption spectroscopy and photoelectron spectroscopy, as illustrated for an organic dye as absorber attached to a p-doped diamond film as donor. Systematic measurements of organometallic dyes (phthalocyanines and porphyrins) as a function of the metal atom are presented for the metal 2p and N 1s absorption edges. In combination with density functional theory one can discern trends that are useful for tailoring absorber molecules. A customized porphyrin molecule is investigated that combines an absorber with a donor and a linker to an oxide acceptor. The bridge to device fabrication is crossed by correlating spectroscopic features with the photocurrent in hematite photoanodes for water splitting. For speeding up the development of new materials and designs of solar cells a feedback loop between spectroscopy, theory, synthesis and device fabrication is envisioned. © 2012 Elsevier B.V.This work was supported by the NSF with the awards CHE-1026245, DMR-1121288 (MRSEC), and DMR-0537588 (SRC), by the DOE under the contracts DE-SC0006931, DE-AC02-05CH11231 (ALS), and DE-FG02-01ER45917 (end station), by the Spanish Ministerio de Economia y Competitividad (MAT2010-21156-C03-01, C03-03, and PIB2010US-00652), and by the Basque Government (IT-257-07). RER and RJH acknowledge support from the NSF with grants CHE-0613010 and CHE-0911543.Peer Reviewe