Electron transport in carbon wires in contact with Ag electrodes : a detailed first principles investigation

The structure and electronic properties of carbon atom chains Cn in contact with Ag electrodes are investigated in detail with first principles means. The ideal Ag(100) surface is used as a model for binding, and electron transport through the chains is studied as a function of their length, applied bias voltage, presence of capping atoms (Si, S) and adsorption site. It is found that the metal\u2013molecule bond largely influences electronic coupling to the leads. Without capping atoms the quality of the electric contact improves when increasing the carbon atom coordination number to the metal (1, 2 and 4 for adsorption on a top, bridge and hollow position, respectively) and this finding translates almost unchanged in more realistic tip-like contacts which present one, two or four metal atoms at the contact. Current\u2013voltage characteristics show Ohmic behaviour over a wide range of bias voltages and the resulting conductances change only weakly when increasing the wire length. The effect of a capping species is typically drastic, and either largely reduces (S) or largely increases (Si) the coupling of the wire to the electrodes. Comparison of our findings with recent experimental results highlights the limits of the adopted approach, which can be traced back to the known gap problem of density-functional-theory

Mutant glycyl-tRNA synthetase (Gars) ameliorates SOD1G93A motor neuron degeneration phenotype but has little affect on Loa dynein heavy chain mutant mice

Background: In humans, mutations in the enzyme glycyl-tRNA synthetase (GARS) cause motor and sensory axon loss in the peripheral nervous system, and clinical phenotypes ranging from Charcot-Marie-Tooth neuropathy to a severe infantile form of spinal muscular atrophy. GARS is ubiquitously expressed and may have functions in addition to its canonical role in protein synthesis through catalyzing the addition of glycine to cognate tRNAs. Methodology/Principal findings: We have recently described a new mouse model with a point mutation in the Gars gene resulting in a cysteine to arginine change at residue 201. Heterozygous Gars^{C201R/+} mice have locomotor and sensory deficits. In an investigation of genetic mutations that lead to death of motor and sensory neurons, we have crossed the Gars^{C201R/+} mice to two other mutants: the TgSOD1^{G93A} model of human amyotrophic lateral sclerosis and the Legs at odd angles mouse (Dync1h1^{Loa}) which has a defect in the heavy chain of the dynein complex. We found the Dync1h1^{Loa/+}; Gars^{C201R/+} double heterozygous mice are more impaired than either parent, and this is may be an additive effect of both mutations. Surprisingly, the Gars^{C201R} mutation significantly delayed disease onset in the SOD1^{G93A}; Gars^{C201R/+} double heterozygous mutant mice and increased lifespan by 29% on the genetic background investigated. Conclusions/Significance: These findings raise intriguing possibilities for the study of pathogenetic mechanisms in all three mouse mutant strains

Application of Digital Terrain Model to volcanology

Three-dimensional reconstruction of the ground surface (Digital Terrain Model, DTM), derived by airborne GPS photogrammetric surveys, is a powerful tool for implementing morphological analysis in remote areas. High accurate 3D models, with submeter elevation accuracy, can be obtained by images acquired at photo scales between 1:5000-1:20000. Multitemporal DTMs acquired periodically over volcanic area allow the monitoring of areas interested by crustal deformations and the evaluation of mass balance when large instability phenomena or lava flows have occurred. The work described the results obtained from the analysis of photogrammetric data collected over the Vulcano Island from 1971 to 2001. The data, processed by means of the Digital Photogrammetry Workstation DPW 770, provided DTM with accuracy ranging between few centimeters to few decimeters depending on the geometric image resolution, terrain configuration and quality of photographs

Resonant Lifetime of Core-Excited Organic Adsorbates from First Principles

We investigate by first-principles simulations the resonant electron-transfer lifetime from the excited state of an organic adsorbate to a semiconductor surface, namely isonicotinic acid on rutile TiO$_2$(110). The molecule-substrate interaction is described using density functional theory, while the effect of a truly semi-infinite substrate is taken into account by Green's function techniques. Excitonic effects due to the presence of core-excited atoms in the molecule are shown to be instrumental to understand the electron-transfer times measured using the so-called core-hole-clock technique. In particular, for the isonicotinic acid on TiO$_2$(110), we find that the charge injection from the LUMO is quenched since this state lies within the substrate band gap. We compute the resonant charge-transfer times from LUMO+1 and LUMO+2, and systematically investigate the dependence of the elastic lifetimes of these states on the alignment among adsorbate and substrate states.Comment: 24 pages, 6 figures, to appear in Journal of Physical Chemistry

Survival impact of adjuvant chemotherapy in patients with stage IIA colon cancer: Analysis of the National Cancer Database.

Utility of adjuvant chemotherapy for stage II cancer remains a matter of debate. Clinical guidelines suggest adjuvant chemotherapy for stage II tumors with high-risk features, in particular T4 tumors. However, limited consensus exists regarding the importance of other high-risk features (lymphovascular or perineural invasion, microsatellite instability). Our study aimed to investigate the impact of adjuvant chemotherapy for stage IIA (T3N0) colon cancer patients. Patients who underwent colectomy for stage IIA colon adenocarcinoma (2010-2015) were identified in the National Cancer Database (NCDB) and divided in two groups based on receipt of adjuvant chemotherapy vs observation. Inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier and Cox proportional hazards regression analyses were performed to compare overall survival between the two groups. Subgroup analysis of patients with specific high-risk features LVI, PNI and MSI was performed. Among 46 688 surgical patients with stage IIA colon adenocarcinoma 5937 (12.7%) received adjuvant chemotherapy, while 40 751 (87.3%) were observed. Five-year IPTW-adjusted survival was higher in the adjuvant chemotherapy group (79.7% [95% CI 79.1, 80.2]) compared to the observation group (70.3% [95% CI 69.7, 70.9]). Patients with high-risk pathological features showed an estimated 5-year survival benefit of 11.3% (78.2% [95% CI 77.4, 79.1] vs 66.9% [95% CI 65.9, 67.8]) when treated with adjuvant chemotherapy. This NCDB analysis revealed a survival benefit for patients with stage IIA colon adenocarcinoma and high-risk features that were treated with adjuvant chemotherapy

Readmissions Within 48 Hours of Discharge: Reasons, Risk Factors, and Potential Improvements.

Hospital readmission rate is an important quality metric and has been recognized as a key measure of hospital value-based purchasing programs. This study aimed to assess the risk factors for hospital readmission with a focus on potentially preventable early readmissions within 48 hours of discharge. This is a retrospective cohort study. This study was conducted at a tertiary academic facility with a standardized enhanced recovery pathway. Consecutive patients undergoing elective major colorectal resections between 2011 and 2016 were included. Univariable and multivariable risk factors for overall and early (<48 hours) readmissions were identified. Specific surgical and medical reasons for readmission were compared between early and late readmissions. In total, 526 of 4204 patients (12.5%) were readmitted within 30 days of discharge. Independent risk factors were ASA score (≥3; OR, 1.5; 95% CI, 1.1-2), excess perioperative weight gain (OR, 1.7; 95% CI, 1.3-2.3), ileostomy (OR, 1.4; 95% CI, 1-2), and transfusion (OR, 2; 95% CI, 1.4-3), or reoperation (OR, 11.4; 95% CI, 7.4-17.5) during the index stay. No potentially preventable risk factor for early readmission (128 patients, 24.3% of all readmissions, 3% of total cohort) was identified, and index hospital stay of ≤3 days was not associated with increased readmission (OR, 0.9; 95% CI, 0.7-1.2). Although ileus and small-bowel obstruction (early: 43.8% vs late: 15.5%, p < 0.001) were leading causes for early readmissions, deep infections (3.9% vs 16.3%, p < 0.001) and acute kidney injury (0% vs 5%, p = 0.006) were mainly observed during readmissions after 48 hours. Risk of underreporting due to loss of follow-up and the potential co-occurrence of complications were limitations of this study. Early hospital readmission was mainly due to ileus or bowel obstruction, whereas late readmissions were related to deep infections and acute kidney injury. A suspicious attitude toward potential ileus-related symptoms before discharge and dedicated education for ostomy patients are important. A short index hospital stay was not associated with increased readmission rates. See Video Abstract at http://links.lww.com/DCR/B237. REINGRESOS DENTRO DE LAS 48 HORAS POSTERIORES AL ALTA: RAZONES, FACTORES DE RIESGO Y POSIBLES MEJORAS: La tasa de reingreso hospitalario es una métrica de calidad importante y ha sido reconocida como una medida clave de los programas hospitalarios de compras basadas en el valor.Evaluar los factores de riesgo para el reingreso hospitalario con énfasis en reingresos tempranos potencialmente prevenibles dentro de las 48 horas posteriores al alta.Estudio de cohorte retrospectivo.Institución académica terciaria con programa de recuperación mejorada estandarizado.Pacientes consecutivos sometidos a resecciones colorrectales mayores electivas entre 2011 y 2016.Se identificaron factores de riesgo uni y multivariables para reingresos totales y tempranos (<48 horas). Se compararon razones médicas y quirúrgicas específicas para el reingreso entre reingresos tempranos y tardíos.En total, 526/4204 pacientes (12,5%) fueron readmitidos dentro de los 30 días posteriores al alta. Los factores de riesgo independientes fueron puntuación ASA (≥3, OR 1.5; IC 95% 1.1-2), aumento de peso perioperatorio excesivo (OR 1.7; IC 95% 1.3-2.3), ileostomía (OR 1.4, IC 95%: 1-2) y transfusión (OR 2, IC 95% 1.4-3) o reoperación (OR 11.4; IC 95% 7.4-17.5) durante la estadía índice. No se identificó ningún factor de riesgo potencialmente prevenible para el reingreso temprano (128 pacientes, 24.3% de todos los reingresos, 3% de la cohorte total), y la estadía hospitalaria índice de ≤ 3 días no se asoció con un aumento en el reingreso (OR 0.9; IC 95% 0.7-1.2) Mientras que el íleo / obstrucción del intestino delgado (temprano: 43.8% vs. tardío: 15.5%, p < 0.001) fueron las principales causas de reingresos tempranos, infecciones profundas (3.9% vs 16.3%, p < 0.001) y lesión renal aguda (0 vs 5%, p = 0.006) se observaron principalmente durante los reingresos después de 48 horas.Riesgo de subregistro debido a la pérdida en el seguimiento, posible co-ocurrencia de complicaciones.El reingreso hospitalario temprano se debió principalmente a íleo u obstrucción intestinal, mientras que los reingresos tardíos se relacionaron con infecciones profundas y lesión renal aguda. Es importante tener una actitud suspicaz hacia los posibles síntomas relacionados con el íleo antes del alta y una educación específica para los pacientes con ostomía. La estadía hospitalaria índice corta no se asoció con mayores tasas de reingreso. Consulte Video Resumen en http://links.lww.com/DCR/B237

Implicazioni geodinamiche delle recenti misure geodetiche nello Stretto di Messina

Il 28 dicembre 1908 lo Stretto di Messina veniva colpito da un disastroso evento sismico di ms=7.5. L'evento è il più forte tra i terremoti italiani degli utimi 100 anni.Published3-143.3. Geodinamica e struttura dell'interno della TerraN/A or not JCRrestricte

Genetic Continuity in the Franco-Cantabrian Region: New Clues from Autochthonous Mitogenomes

Background: The Late Glacial Maximum (LGM),,20 thousand years ago (kya), is thought to have forced the people inhabiting vast areas of northern and central Europe to retreat to southern regions characterized by milder climatic conditions. Archaeological records indicate that Franco-Cantabria might have been the major source for the re-peopling of Europe at the beginning of the Holocene (11.5 kya). However, genetic evidence is still scarce and has been the focus of an intense debate. Methods/Principal Findings: Based on a survey of more than 345,000 partial control region sequences and the analysis of 53 mitochondrial DNA (mtDNA) genomes, we identified an mtDNA lineage, HV4a1a, which most likely arose in the Franco-Cantabrian area about 5.4 kya and remained confined to northern Iberia. Conclusions/Significance: The HV4a1a lineage and several of its younger branches reveal for the first time genetic continuity in this region and long-term episodes of isolation. This, in turn, could at least in part explain the unique linguistic and cultural features of the Basque region

Strain-controlled criticality governs the nonlinear mechanics of fibre networks

Disordered fibrous networks are ubiquitous in nature as major structural components of living cells and tissues. The mechanical stability of networks generally depends on the degree of connectivity: only when the average number of connections between nodes exceeds the isostatic threshold are networks stable (Maxwell, J. C., Philosophical Magazine 27, 294 (1864)). Upon increasing the connectivity through this point, such networks undergo a mechanical phase transition from a floppy to a rigid phase. However, even sub-isostatic networks become rigid when subjected to sufficiently large deformations. To study this strain-controlled transition, we perform a combination of computational modeling of fibre networks and experiments on networks of type I collagen fibers, which are crucial for the integrity of biological tissues. We show theoretically that the development of rigidity is characterized by a strain-controlled continuous phase transition with signatures of criticality. Our experiments demonstrate mechanical properties consistent with our model, including the predicted critical exponents. We show that the nonlinear mechanics of collagen networks can be quantitatively captured by the predictions of scaling theory for the strain-controlled critical behavior over a wide range of network concentrations and strains up to failure of the material